Exhaust Back Pressure Testing - 2 Methods

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  • เผยแพร่เมื่อ 18 ธ.ค. 2024

ความคิดเห็น • 442

  • @garywanamaker2602
    @garywanamaker2602 8 ปีที่แล้ว +25

    Your ability to break down complex concepts into understandable (and often hilarious) terms never ceases to amaze me. I've learned so much from these videos - not just about automotive issues but about the troubleshooting process in general. Thanks for the time you put into these!

  • @philkohl9679
    @philkohl9679 7 ปีที่แล้ว +41

    In a Buick I worked on 40 years ago I had a similar situation. The car ran fine at idle... but as the load and speed went up the engine bogged badly. The problem was a collapsed exhaust pipe. Not that you could see any deformation the outside .. but the pipe delaminated and one layer collapsed and choked off the inside. I couldn't believe it until I sawed it open. Replaced the pipe and all was well. Kept that pipe on the wall for years.
    Phil

    • @Trident_Euclid
      @Trident_Euclid 5 ปีที่แล้ว +2

      Laminated exhaust pipe?

    • @douglasgerrard5094
      @douglasgerrard5094 5 ปีที่แล้ว +1

      Phil Kohl I had the same happen long time ago.

    • @stevendunn6255
      @stevendunn6255 5 ปีที่แล้ว +7

      GM used a double wall exhaust pipe on many vehicles from 1969 to 1973. If you were driving with a hot exhaust pipe [ high speed cruising for example ] and went thru a large puddle of water, the cold water would hit the exhaust pipe, then the inner pipe layer would collapse and block the exhaust flow. You had to cut the pipe open to see it most of the time as it would do this near the middle of the length of the exhaust pipe. I saw this on a Bonneville and an El Camino..

    • @pitchforkpeasant6219
      @pitchforkpeasant6219 ปีที่แล้ว +1

      Sounds like a problem you’d see in a cast iron plumbing pipe which will “delaminate” over time. Went to put a pipe plug in once and couldn’t get any to fit. Even chipping some away

  • @billyd1703
    @billyd1703 8 ปีที่แล้ว +2

    I'm waiting for you to get ahold of an old 70's, 80's model without all the high tech computers involved. All your "gadgets" are over my head. Love It.

  • @satamanschmidt3428
    @satamanschmidt3428 8 ปีที่แล้ว +18

    The 3800, best V6 ever created. I miss mine already. Small, light powerful and can be swapped out in four hours. A thing of beauty is a joy forever. With the supercharger this thing was fast as well.

  • @RealCadde
    @RealCadde 8 ปีที่แล้ว +82

    What i really wanted to see was what was plugging the exhaust.

  • @co1bateman
    @co1bateman 8 ปีที่แล้ว +7

    i'm just a diy, driveway joe, i find this kind of stuff absolutely fascinating. way beyond my skill set, another gr8 video from SMA ,,Thx Eric O

  • @jcduff-bn2eo
    @jcduff-bn2eo ปีที่แล้ว +3

    23:44 I need to see this video it really helped me with my problems with my 2002 Chevy Silverado I could not figure out what was going on with my truck until I saw this video. I had the same problem with my exhaust stopped up

  • @DaTwistedOne1
    @DaTwistedOne1 8 ปีที่แล้ว +11

    Every so often I hear "Welcome to the self made auto channel" and I think, "Yes it is". Then I remember you are saying South Main..lol

  • @lesbender236
    @lesbender236 8 ปีที่แล้ว +61

    Are you going to show where the blockage was,CAT,crushed pipe,muffler?

  • @scflooring8658
    @scflooring8658 5 ปีที่แล้ว +1

    You the man Eric nothing like watching a real pro do his job. Not many mechanics like you anymore really wish you worked in Maine you would have a new customer. Keep up the great work! Really enjoy your videos watch them daily!

  • @roadstar499
    @roadstar499 6 ปีที่แล้ว

    I watched a couple of guys do these bad cat bad flow video's on different cars... the performance varies a lot... i am 99 % sure i have this issue and possibly i installed my distributor in a tooth off because it used to be drivable and idle like a kitten...but when i drove it ..it lacked half its horse power bucked and hesitated intermittently... thax for all your great repair video's...

  • @btasler
    @btasler 6 ปีที่แล้ว +3

    IMHO you are too quick to beat yourself up. It was a good hypothesis, and you went through the steps to prove it. The easy stuff is easy, and if you have to get dragged through the mud a little bit to satisfy yourself on the hard ones, that's okay.
    Every decision you (or anybody) make is done with consideration of the cost associated, based on previous experience. This didn't strike me as too high of a cost to really get a solid diagnosis. Sure it's a bit of time spent, but that time spent will yield positive results for you (and now me) in the future, so it was time spent but not time wasted.
    Once again, thank you.

  • @rogereastman3187
    @rogereastman3187 ปีที่แล้ว +2

    Seems to me that the old school vacuum pressure gauge test....is quicker and easier to find the problem. Which as being the old coot that I am.....is very encouraging

  • @backwoodsfreak
    @backwoodsfreak 4 ปีที่แล้ว

    You guys want a good laugh turn on the self generated captions on this and watch it again. Love the videos keep up the good work, (not on weekends though) I appreciate what you do here. Helped me not only with certain procedures but you explain it to the why people like myself that like to "get it" the first time.

  • @jimintaos
    @jimintaos 6 ปีที่แล้ว +2

    Oddly, I believe I am dealing with the same issue on a 2001 Toyota 4runner. Idles like a champ-sounds beautiful. Then you get out of the driveway and 10 to 20 miles an hour, can't get above 1800 rpm. Exhaust is wimpy and very hot at idle. A while back I had to replace the turbo on my lady friend's Subaru and while I was doing it, I came across a mention that when the turbo goes out, it dumps a lot of oil into the catalytic converter and plugs it up. I took it out and sure enough, filled with sticky, nasty carbon gunk. New cat, oil changes every 500 miles for the first three thousand miles and 20,000 miles later it is still running like a champ. Now, back to the 4runner-time to order cats--dagnabbit.

  • @MrJcardimen
    @MrJcardimen 8 ปีที่แล้ว +3

    Another great video. So glad you decided to make it once you saw the issue and its magnitude. I'd love to see a follow up that shows where the blockage was and the "after" readings.

  • @shaneharrison4775
    @shaneharrison4775 4 ปีที่แล้ว +1

    Best constipation video I've seen with exception of that 4 banger frontier from nissan

  • @kevinedward1234
    @kevinedward1234 6 ปีที่แล้ว +2

    Eric, great video, great to learn multiple methods of diagnostic testing to verify a suspected failed component!!

  • @AntonioClaudioMichael
    @AntonioClaudioMichael 2 ปีที่แล้ว +1

    So awesome of ivan to make you a Pressure Transducer Eric O @3:20 @SouthMainAutoRepairLLC

  • @HouseCallAutoRepair
    @HouseCallAutoRepair 3 ปีที่แล้ว +5

    4 years ago... And still relevant! Nice episode!

  • @scflooring8658
    @scflooring8658 5 ปีที่แล้ว +6

    Eric you should make up some hats or shirts from SMA with “there’s your problem lady” I would definitely buy one and I’m sure others would too!

  • @mikechiodetti6737
    @mikechiodetti6737 6 ปีที่แล้ว

    I've had several V8 Fords (460 cu in) that had the wrong cat on the vehicle. The cat(s) were plugged. This was pre pressure transducers. The old vacuum gauge at the intake manifold port, start the engine, good vacuum reading at sea level, 20 inches, until reved. WOW! Literally, the gauge went to zero within 10 seconds, shutting off the engine!
    Disconnected the "Y" pipe at the cat, STRONG RUNNING ENGINE!
    Just another way to test.

  • @wyattoneable
    @wyattoneable 8 ปีที่แล้ว +1

    I see the references in the "Information" icon. Thanks, that helps. Ivan will be proud of your math skills and the display of his Pine Hollow shirt was a class act. I appreciate that you thought to make a video. As you know, I'm a sponge for learning this stuff and videos like yours sure helps! Plus you crack me up with your sense of humor. See you on the next one and thanks for the help on my truck. My wife is very happy to have "her" truck back, I thought it was mine but whatever. lol

  • @cojones8518
    @cojones8518 8 ปีที่แล้ว +4

    It's easier to take off the digital EGR valve on GMs and use an adapter plate for back pressure tests. Better than risking breaking an O2 off in the manifold. You can make an adapter pretty easy out of a small piece of aluminum plate. Drill and tap the center hole for whatever size fitting you use on your gauge.
    You can use the gasket to lay out the hole pattern.

  • @ronaldcach2779
    @ronaldcach2779 8 ปีที่แล้ว

    It does not hurt to double check one method with another if something weird is happening. You did it again Eric, THANKS FRIEND

  • @johnaclark1
    @johnaclark1 8 ปีที่แล้ว +2

    I learn so much from every video. Sure appreciate you taking the time to post this stuff.

  • @jonypalacios
    @jonypalacios 7 ปีที่แล้ว +17

    hey Erick.I have been watching your videos and noticed that in every other video you have different scan tools. and was wondering if you could make a video comparing the different scan tools. thanks for sharing your knowledge.

  • @kc360awareness
    @kc360awareness ปีที่แล้ว +1

    Cool. Eric sporting the PHAD shirt.

  • @firstielasty1162
    @firstielasty1162 10 หลายเดือนก่อน

    Thanks, very informative. That pressure transducer is a really cool tool.
    The cause of the high pressure would be good to know, I'd guess a clogged cat.
    Another reason that babying your car is just no good. You're asking for stuck rings and the resulting oil consumption, or this. This (if it is a clogged cat) is unusual, but the cat does require heat to function, and I suspect that many short and/or easy trips reduce catalyst life.
    I make sure I always get on it a few times- good for my car, and for me, too.
    That exhaust valve opening is probably at about 40 degrees before bottom dead center, rather than at it.
    Thanks for your informative and entertaining videos!

  • @RedneckRickem
    @RedneckRickem 8 ปีที่แล้ว +1

    Just had a GMC Savana with the same problem, idles great, but no beans when you get on it. The van had just had a distributor replaced so initially thought timing was off, not the problem, took the O2 sensor out, gave her some beans and had lots of give, easy way to test for plugged Cat.

  • @johnchristopherson2718
    @johnchristopherson2718 8 ปีที่แล้ว +4

    Could you have used a temperature reading using Non-contact Digital Laser Infrared Thermometer at the cat to confirm the symptoms?

  • @savinggracekennels5588
    @savinggracekennels5588 2 ปีที่แล้ว

    Jerry is Jodie's cousin for the record😂 Discovered your channel while researching testing procedures for Exhaust Backpressure Sensor on 6.0 Powerstroke. I'm learning how to use my new scan tool and this will be my 1st attempt at setting up the scope. Matco Maximus 4.0. Replaced sensor (OEM), pigtail & tube couple of mths ago. Not sure if I may have disrupted something with the MAP sensor as I rebuilt the fuel injectors on that side last week and now this. I should've replaced the vacuum line when I noticed how stiff it was. Enjoyed watching you thoroughly test your hypothesis.

  • @samg5543
    @samg5543 8 ปีที่แล้ว +2

    A naturally aspirated engine probably would never be able to create that much back pressure. This is definitely a special case. Good work.

  • @workingshlub8861
    @workingshlub8861 8 ปีที่แล้ว +3

    good lesson eric..wouldnt a clogged exhaust make it overheat from just running at idle?

  • @anomamos9095
    @anomamos9095 8 ปีที่แล้ว +16

    Has anyone simply tried a tire pressure gauge and an air compressor? You pick a cylinder with an open exhaust valve and pressurise it and read what the gauge gets to. Anything higher than atmospheric and the exhaust is blocked.

    • @waynemoore5259
      @waynemoore5259 5 ปีที่แล้ว +2

      I like your idea boss

    • @kain0m
      @kain0m 4 ปีที่แล้ว

      @@waynemoore5259 Problem with that is that engines flow an awful amount of air. Regular shop air won't do much there.

    • @daveschidlmeier6425
      @daveschidlmeier6425 3 ปีที่แล้ว +1

      The only problem is, if any other cylinder has even a slightly cracked exhaust valve. Your reading is out the window. It would work on a single cylinder engine. We're talking multi cylinder engines. To be sure you'll have to pull the valve covers.

    • @anomamos9095
      @anomamos9095 3 ปีที่แล้ว

      @@daveschidlmeier6425 . As the test is for a blocked exhaust system a bad valve would be a different problem.

    • @daveschidlmeier6425
      @daveschidlmeier6425 3 ปีที่แล้ว

      @@anomamos9095 sorry I didn't mean to confuse you by the turm " craked valve". I should have stated, if any other exhaust valve is slightly open at the time you pressurized your test cylinder, the air would go into an other cylinder , giving you an inaccurate pressure test for a plugged exhaust system. You would have to verify all exhaust valves are completely closed and sealed at the time of test... But I do like the way you think!

  • @donaldrackley626
    @donaldrackley626 4 ปีที่แล้ว +1

    That was so interesting. Fantastic video Mr owe

  • @93grandamgt
    @93grandamgt 7 ปีที่แล้ว +2

    love the 3800 supercharged engines definitely fun in my GTP I had

  • @frugalprepper
    @frugalprepper 8 ปีที่แล้ว +2

    Jerry-Rigged comes from an old english sailing term "jory saile" which means a make shift sail/rigging setup on a ship.

  • @motorcyclesandridingfree2899
    @motorcyclesandridingfree2899 8 ปีที่แล้ว +1

    Good video and very good use of the pressure transducer. You make Ivan sound like a mad scientist lol. You both do a very good job with your videos

  • @ChrisLove713
    @ChrisLove713 ปีที่แล้ว +1

    Back pressure is never your friend. It's always your enemy. The ideal setup is a straight pipe with no cat or muffler... while that's typically illegal to drive on the streets (and loud as hellfire), it's absolutely ideal for perfect flow and no volumetric reflection or power robbing back pressure.

    • @konasan
      @konasan ปีที่แล้ว

      There may be exceptions. Consider this: I bought a used CJ5 Jeep that looked good, with a strong engine (304 v8) and a suprisingly low price. It was all good until I got onto a steep off road hill in 4wd low and instead of climbing the hill it hopped like a rabbit as the tires would slip with any throttle at all. The engine had too much power! I replaced it's after market headers and mufflers (cherry bombs) with a stock single muffler (to get some back pressure) and 4wd worked like it was supposed too. The gearing was matched to the horse power which was influenced by the back pressure. I hated to lose the cherry bombs. They were pretty.

  • @graymodeler
    @graymodeler 8 ปีที่แล้ว

    I have this engine on a 95 Riviera. I got a lean code. Turned out to be a blown supercharger gasket that was found with a smoke test. Early ones had an awful accessory bracket covering the water pump and the SC snout. I think they built the engine around the water pump. Snout couplers rattle on these. I replaced mine a while back.

  • @donaldales7739
    @donaldales7739 ปีที่แล้ว +1

    I'm old school, if you think you have a restricted exhaust, raise up on hoist tap test converters check for noise. If you think firebrick is plugged with oil and soot, disconnect header pipe and run engine.....

  • @JimmyMakingitwork
    @JimmyMakingitwork 3 ปีที่แล้ว

    I have an adapter that threads into the O2 hole for a vacuum/pressure tap. Intake vacuum will show restricted exhaust as well, if it can’t get air out, it take air in.
    All your vids are popping up since I subbed. :)

  • @CHIBA280CRV
    @CHIBA280CRV 8 ปีที่แล้ว +3

    Hey thanks for sharing the find with us...excellent ..

  • @stevent1074
    @stevent1074 6 ปีที่แล้ว +1

    Great way to go from a hunch to proving it with a systematic approach to troubleshooting. You’re a great mechanic-Thanks for sharing your experience 👍🏻

  • @michaelduke1405
    @michaelduke1405 5 ปีที่แล้ว

    When exhaust from the pipe wouldn't blow out a birthday candle; rearranging the spark plug wires during half time and petroleum jelly on the wipers could make for a long ride home. Backfiring through the muffler usually blew it to small pieces so the back pressure returned to normal. The un-burned gas left in the exhaust was used to help keep the valves at a lower operating temperature.

  • @shorty5352
    @shorty5352 6 ปีที่แล้ว

    Another indication or way to find out with boosted vehicles, On these Regals if you bring up the boost gauge on the cluster, it would give you a quick indication when you go into positive intake pressure, it would shoot up over the stock 8-10 psi under load, usually under part throttle to WOT and show you about the same results and fault.

  • @subwayguy1610
    @subwayguy1610 8 ปีที่แล้ว

    Hey Eric, my birthday is in 2 days. And a birthday wish from you would be great! Love your videos.

  • @DarrenCoull
    @DarrenCoull 8 ปีที่แล้ว +5

    I recognised that engine - exact same I expect as the Holden Commodore 3.8L V6 Supercharged - of course in the Commodore it's pointing the right way with the pulleys at the front and driving the correct (rear!) wheels ;-)

    • @matt.604
      @matt.604 6 ปีที่แล้ว +1

      Holden is Australian

  • @jessbayardo2068
    @jessbayardo2068 8 ปีที่แล้ว +2

    good video, thanks, can you share the site on how to make that pressure transducer please, thank you again

  • @shadowdog500
    @shadowdog500 8 ปีที่แล้ว +3

    Could you hook Ivan's pressure transducer up to the line that you had running to the front O2 bung? It would be neat to see a plot of the pressure there instead of just looking at the bouncy needle. It would also be good to confirm/calibrate the transducer output before using it by hooking an air chuck adapter to it and testing the pressure of car and truck tires that were inflated to known values. Chris

  • @joemartines5208
    @joemartines5208 7 ปีที่แล้ว

    I thank you very much for sharing your knowledge on demostraiting on how to used the EScope t diagnost a plug converter. Thank you.

  • @russellhattal2363
    @russellhattal2363 ปีที่แล้ว

    Eric, just to let you know since ya asked, Jerry is Wills best friend, That poor bugger that everyone is firing at { : Love Your Work!
    Thank You { :

  • @robwinder4282
    @robwinder4282 4 ปีที่แล้ว +1

    Seems like the “hose effect” might be more from the expansion of the rubber hose absorbing / dampening the pressure before it gets to your gauge. What do you think?

  • @richardwhite6943
    @richardwhite6943 3 ปีที่แล้ว

    Where can I buy this pressure transducer? The link for tools and toys is not working. Also great video and your not the only one that didn't trust the results of it. The in cylinder pressure testing is the future of engine performance mechanical diagnostics and even tho you didn't really know why you made the video it for sure helped me gain a little more experience with a known plugged exhaust. Thanks Richard White, shop Owner/Technician

  • @Wildturkey10121
    @Wildturkey10121 5 ปีที่แล้ว

    the fact that you didn;t trust your data is what makes you such a great mechanic! I'm having an issue I wish you could deal with right now honestly p0420 I cant afford cats and am hoping it is o2 sensors but I don't have a scan tool to do any testing. I could use the temp test but I have one of the chevy 2.4 motors with the oil burning issue and had that fixed by top end rebuild a year or so ago but the car has been fine till today.

  • @kellismith4329
    @kellismith4329 2 ปีที่แล้ว

    Loving the crickets in the background

  • @punker6506
    @punker6506 8 ปีที่แล้ว +3

    i had one that was 8 psi at idle and still ran. gotta love the w body.

  • @haywardsautomotive6156
    @haywardsautomotive6156 8 ปีที่แล้ว +1

    Nice case study! Look at my FB answer on your SMA page @1AM and my @9AM one. The 2 things that jumped out at me was when the exhaust valve opened prior to BDC the pressure immediately increased which normally it will continue to drop until after BDC and the piston is just starting it's exhaust stroke and the other was when the intake valve opened pressure dropped like normal but then immediately rose back up until the exhaust valve closed when normally the pressure would drop after the intake valve opened due to intake vacuum prior to it starting on the intake stroke BUT being supercharged the intake pressure would change the waveform to a less pronounced drop & being supercharged it just keep throwing the beans to it. What failed on the original engine & it had to be getting HOT & knocking like crazy?...How bad did it go BOOM? Snap-on has a new adapter that comes with their vacuum/pressure tester that has 2 different adapter threads & the hole is @1/4" to dampen pressure pulses. Nice transducer from Ivan! As usual great video & another satisfied SMA customer!

  • @carlodonnell146
    @carlodonnell146 2 ปีที่แล้ว

    I made one with a o2 sens by drilling out the center and installing a piece of copper tube with some epoxy and it works

  • @philh9238
    @philh9238 7 ปีที่แล้ว

    i understanded the backpressure test perfectly on the scope now!

  • @FJB8885
    @FJB8885 ปีที่แล้ว

    Jerry was the German soldier back in WW 2
    Great video.

  • @ozzstars_cars
    @ozzstars_cars 8 ปีที่แล้ว +1

    Enjoyed the vid Eric. Nice comparison between the mechanical and digital data.

  • @TheDisgruntledMechanic
    @TheDisgruntledMechanic 8 ปีที่แล้ว

    Your right as you told me that this video would be interesting and you were right. And I forgot to ask when at SMA, what was plugged?

  • @canonevans1207
    @canonevans1207 5 ปีที่แล้ว +2

    Hey Eric, with a huge blockage like that would you be able to recognize the blockage by putting your hand kinda over the exhaust at the rear of the car and having someone hit the throttle?

  • @ColdWarVet607
    @ColdWarVet607 6 ปีที่แล้ว

    BDC occurs before the point at 28.5 ms you noted on the o-scope. At 10:00 you put cursor at time peak to peak divided by 4 or at 28.5 ms and said its BDC. But...it was at 501 mv or the average level of the exhaust pressure trace section. Problem with that is, about 5/8 of a div before that point or what would be 27.25 ms we see pressure hit a low then rise up to about atmo at 28.5 ms.
    The piston can't just have hit BDC at 28.5 if pressure is rising between 27.25 and 28.5 ms. BDC was actually hit at the low point of the curve about 5/8 of a div or at 27.25 ms before the 28.5 ms point you noted.
    At 28.5 ms the valve is nearly or already fully open. The valve started opening at 27.25 ms because pressure starts rising right after that. I thought perhaps the piston may be rising but we are not 1/4 way thru time and the valve should open/opening before piston rises.
    So BDC first occurs at 27.5 ms and the pressure rising at 27.5 ms is start of valve opening. At 28.5 ms I'd say thats where the exhaust stroke and piston physically rising starts, not where BDC occurs albeit the piston may still be at BDC then.
    Don't mean to be anal here, it was strange to hear you say this is BDC and the scope shows pressure has already been rising, we think of BDC as the low point in pressure.It may have been between to say, this is start of exhaust stroke at 28.5 ms.
    Or......I could be completely wrong.....................
    Please don't shoot me I'm only the piano player.
    Your Navy Nuc Sub Veteran fan in internet world -Don

  • @treowayne
    @treowayne 8 ปีที่แล้ว +1

    If you suspect a clogged cat, remove the front oxygen sensor. It will be very noisy, but if it runs better (and it should run a LOT better if the cat is clogged), you have an exhaust restriction.

  • @davidhoekje7842
    @davidhoekje7842 8 ปีที่แล้ว

    I would speculate that the rubber hose on the O2 sensor port was getting heated from the exhaust, causing the reading to fall over time. Very interesting piece. Thanks!

  • @comingundone27
    @comingundone27 7 ปีที่แล้ว

    I just ran into this on a 02 Malibu. 2 psi at idle but 15psi raised up. Engine ran just fine.

  • @autotech1467
    @autotech1467 6 ปีที่แล้ว +1

    So helpful! Very good video

  • @johnnyautotech4722
    @johnnyautotech4722 8 ปีที่แล้ว

    HI Eric, Nice testing method,, I had a Buddys GTP 3800 sc with a clogged Cayt,, so bad it tore the tubular exhaust manifold open , Banged it back together and mig welded it closed ,, wonder what kind of back pressure he had ,,

  • @mohabdallah992
    @mohabdallah992 5 ปีที่แล้ว +1

    Great analysis man

  • @michaelherbert8213
    @michaelherbert8213 8 ปีที่แล้ว

    Whoa. Personally I hate trying to remove an o2 sensor to hook up a back pressure gauge. In NY that's easier said than done. I also don't drill holes in the exhaust either, I suppose it wouldn't hurt if you plugged it back up. But yeah, I will try it your way now. thanks for sharing.

  • @Fahrenheit38
    @Fahrenheit38 8 ปีที่แล้ว +10

    Jerryrig is just a modern bastardization of a ye old english phrase "jory saile" which meant Makeshift sail.

    • @I_M_Nonno
      @I_M_Nonno 6 ปีที่แล้ว +1

      That may be, but I've always known it as WWii GI solder slang for hastily repaired German equipment and now a days no one remembers who jerry was.

    • @davidworsley7969
      @davidworsley7969 6 ปีที่แล้ว +1

      2 Explanations-Jerry rig-poor quality repair; Jury rig-using parts to hand to effect a temporary repair.

    • @acidking202
      @acidking202 5 ปีที่แล้ว

      @@davidworsley7969 Jerry is the "POLITICALLY CORRECT " version of JEWRY rigged. Jewish, and as time goes on Italians, Mexicans , Etc, were considered CHEAP, or excessively poor,so a poorly rigged repair with little to no expense , was so Named.

    • @davidworsley7969
      @davidworsley7969 5 ปีที่แล้ว

      @@acidking202 Can't see it myself-any evidence?

    • @acidking202
      @acidking202 5 ปีที่แล้ว

      @@davidworsley7969 Just The word of an old jewish neighbor who duct taped the crack in his kitchen sink while his son giggled in the background. He Called it the JEW-Rigged plumbing Repair. I cant think of it at the moment but there is a Loosely translated french expression about the boy who used a safety pin to hold up his Gold spun Trousers, There is the expression "N-Rigged", It basically can be used by any ethnic group, But "Jerry" sort of takes the Insulting factors out,

  • @Super032208
    @Super032208 8 ปีที่แล้ว +1

    @South Main Auto Repair ?? how was the reading on the 02 sensors

  • @ericcorse
    @ericcorse 8 ปีที่แล้ว

    Excellent tutorial Eric O

  • @salvadordlicon9467
    @salvadordlicon9467 8 ปีที่แล้ว

    Cool video. Its hard to believe that backpressure was so high.

  • @dalandser562
    @dalandser562 7 ปีที่แล้ว +1

    @15:04 Whoa. WHOA! rofl
    Noob question - so cylinder pressure will be the same even with a spark plug removed? It makes sense since the piston is still traveling to the top of the stroke since it's connected to the crank shaft and has to travel the same path as usual.

    • @SouthMainAuto
      @SouthMainAuto  7 ปีที่แล้ว +1

      Yes except it goes into a vacuum at the bottom of the stroke and there is no "pressure" from combustion

    • @dalandser562
      @dalandser562 7 ปีที่แล้ว

      Got it. So the pressure would be way more during combustion, but since you remove the spark plugs in each cylinder as you go through and compression test them then the pressure is usually the same. I've seen numbers from 140-190 (psi?) on tests I've watched so I guess you knew 50 psi was low enough to be indicative of a leak. This channel has taught me a lot about taking guesswork out of fixing vehicles.

  • @rrmech11
    @rrmech11 8 ปีที่แล้ว +1

    Awesome as always
    Mr O
    😎😎😎😎

  • @jameybarisoff
    @jameybarisoff 4 ปีที่แล้ว +1

    Where was it plugged and what did you change? Also how to determine where it is plugged.

  • @patricktonz7833
    @patricktonz7833 8 ปีที่แล้ว

    Keep the videos coming, great case history !

  • @vincebauer4777
    @vincebauer4777 7 ปีที่แล้ว

    great video I didn't no u could use your fuel pressure gauge for that and does Ivan sell them to anyone

  • @mitchell5828
    @mitchell5828 ปีที่แล้ว

    Thank you-
    Do you happen to know what the maximum sample rate of that transducer is? I was curious just how fast of pressure measurement I could take with something similar. It's two stroke over 10k rpm wanting it to be able to at least sample every crank degree. I'm new to this but id assume I'd need a sensor at least 60khz? Didn't know if that even exists

  • @davesministry7789
    @davesministry7789 8 ปีที่แล้ว

    Old school, method I started doing 1970"s when I found a lot of plugged converter's. You just put the engine in to, very easy, except for your neighbor's. Remove and tie up the exaust pipes and drive it.

  • @billb6899
    @billb6899 ปีที่แล้ว

    Similar symptoms on my 1994 Olds 3800 (love these engines!). Runs fine under 2000 rpm, then bogs like crazy. Ordered a used el cheapo gauge set on eBay today - after testing everything else I could think of and studying live data for hours I'm suspecting exhaust has to be clogged. That and the cat has been rattling for a couple years...
    Similar symptoms on a Safari van a few years back, but it eventually self-cleared (out the tailpipe).
    Guess I'll have to bite the bullet this time and get a cat. A shame really, no downstream sensor on a 94 so no MIL for cat efficiency.

  • @stevesgarage1977
    @stevesgarage1977 8 ปีที่แล้ว

    That was awesome I have never seen a reading that high

  • @gmak1n785
    @gmak1n785 2 ปีที่แล้ว

    Great video dude thanks for sharing

  • @PineHollowAutoDiagnostics
    @PineHollowAutoDiagnostics 8 ปีที่แล้ว +2

    Awesome testing, Eric! Cool to see my psi transducer in action! Now I'm wondering how you saw 7V on that...did I give you Version 1.0 without a 5V regulator?
    One note that someone brought up in one of ScannerDanner's vids is that the in cylinder pressure during the exhaust stroke will always be higher than at the O2 sensor since the exhaust valve orifice acts as a restriction. Try a snap throttle on a known-good vehicle and you will see what I mean.
    Don't wanna get slid by trusting your data blindly! Kudos for using two methods to confirm the diagnosis. A true scientist!

    • @SouthMainAuto
      @SouthMainAuto  8 ปีที่แล้ว

      Yes sir this is the OG 1.0 no regulator just straight hard core haha. It is funny you mention that because the whole night I was thinking... why was that different! Then about 3am I awoke and smiled because it finally hit me :)

    • @PineHollowAutoDiagnostics
      @PineHollowAutoDiagnostics 8 ปีที่แล้ว +1

      Oh man science experiments are keeping you up at night huh? Well you might as well keep it simple if it works; with a 5V reg it would top out at 175psi unless you upgraded to a higher range transducer!

    • @phillipdotson3589
      @phillipdotson3589 8 ปีที่แล้ว +1

      +motoYam82
      you should do a video on pressure transducers or a how build one and the science behind it

    • @tctwg1
      @tctwg1 6 ปีที่แล้ว

      Pine Hollow Auto Diagnostics 🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕

    • @tctwg1
      @tctwg1 6 ปีที่แล้ว

      Pine Hollow Auto Diagnostics 🖕

  • @thomasstreetman8066
    @thomasstreetman8066 2 ปีที่แล้ว

    I once had a 1983 Ruick Begal with a 231 cubic inch engine and even though it wasn't blown, it felt like it was blown. It went from 0-60 in like 4.7 days. It was a dog. The Grand Nationals and GNX were sweet though.

  • @bborkzilla
    @bborkzilla 8 ปีที่แล้ว +3

    Well at least you knew all the exhaust gaskets were tight!

  • @themfknightrider420
    @themfknightrider420 8 ปีที่แล้ว +1

    dang first video i caught this early from you, great video, good moring

  • @aboutmyfathersbusiness8324
    @aboutmyfathersbusiness8324 8 ปีที่แล้ว

    Usually the pre cats melt and plug the post cats. Had my vette do that exact thing. When plugged, nothing when the beans were applied. Would have loved to see the SMA chain saw action to the exhaust and beans given at the end...

  • @philmerrifield1163
    @philmerrifield1163 4 ปีที่แล้ว +8

    20:44 wank means something completely different in Britain 😂

  • @subwayguy1610
    @subwayguy1610 8 ปีที่แล้ว +1

    3800 is notorious for knocking if conditions aren't right. The stock exhaust was designed horribly and is way too restrictive. Removing the u-bend just before the resonator deletes a good chunk of knock. Actually, upgrading to headers is the #1 way to eleminate knock on these motors (besides intercooling). I don't think there is much hope for the engine at this point.
    You should hook up the Snap-On scan tool and see what value of KR comes up. It should have less than 1 degree lol.

  • @boopunn
    @boopunn 7 ปีที่แล้ว

    Did you happen to see if the fuel trims were running high negative? I have a BMW I just rebuilt but bank 1 is running -28 and throws the computer into open loop fault. I am going to test the cats today.

  • @TraceElements-ti5ke
    @TraceElements-ti5ke 3 ปีที่แล้ว

    I could watch all night

  • @testosteroneinc.3800
    @testosteroneinc.3800 8 ปีที่แล้ว +8

    Thanks for the new vids Mr O. We are like crackheads. No going back now. 😎

  • @chekelley6861
    @chekelley6861 8 ปีที่แล้ว

    On plugged cats that are only showing 4 or 5 psi back pressure I think it would be harder to spot on the in cylinder transducer.

  • @JamesSmith-xs7sr
    @JamesSmith-xs7sr 2 หลายเดือนก่อน

    True! A Dr friend of mine can measure constipation by burping backpressure!

  • @AntonioClaudioMichael
    @AntonioClaudioMichael 2 ปีที่แล้ว +1

    Wow 70 Pounds Of Back Pressure that is impressive it even runs or idles pretty strong motor For sure Eric O good Video very informative @SouthMainAutoRepairLLC