I've had the paid channel for almost 2 years. Even having experience I find the channel exceptional for training. Let's say, top 3 best on You Tube IMHO. It has something for everyone for sure.

I love advanced diagnostics , this guy is a diagnostics master in automotive.

He gets to the root issues quickly, teaches his tricks all without editing, he's the real deal!

You are the Mike Rowe of KZfaq mechanics my friend. Top notch teacher and content!

Straight to the points. All of them. Acknowledged mistake in assumption and explained it all clearly. Thanks, Dan!

I like watching you do things hands on which puts things in perspective for those of us who lack experience with troubleshooting in certain areas. +1

I had a 94 Chrysler Laser years ago with intermittent low compression on one cylinder similar to this case. It turned out to be a bad valve guide. Using a compression gauge it would read bad one time and OK the next. It also fouled the plug with the bad valve. It was bad from new. The dealer knurled the guides and it worked for 6 months or so, long enough to get out of warranty. I ended up replacing the cylinder head after which it ran far better than when new. Oil in the cylinder made it want to pre-ignite. The knock sensor backed off the timing and it was a stone. After the fix I could lay rubber with it.

The best I’ve ever seen do it so far

Can't get much more professional than that, Thank you very much.

Excellent video. Although I don’t understand the scope diagnosis completely it certainly opened my eyes to deeper diagnostic techniques.

Happy to see that Pico scope out. Great Job Paul it's always a pleasure to watch you work.

Rear valve cover isn't that bad on that van. I did stem seals on one at 485,000 miles. Last I heard it was still running just fine North of 500,000. Commercial van with lots of miles and few cold start heat cycles as well as being in an arid environment and having a dedicated mechanic helped it reach a round trip to the moon and back. Great new tools for the toolbox on my shoulders. Thanks Paul.

Thanks Paul, The real time out in the field diagnostics like this drive the learning from the Premium Channel home. Take care Bill

My daughters 2002 mazda626 has a cylinder 3 misfire, changed the spark plug, coil and wires with no change with rough idle I’m at my wits end. Your video has given me other possibilities to explore. Thank you for your video.

I just changed the heads on the 2000 Ranger 3.0 with 188,000 miles. They had known exhaust valve issues over time. Turns out I had cylinders 4 and 6 getting coolant in the chamber which was cracking spark plugs and then once I had the old heads on the bench, 5 out of 6 had brake parts cleaner leak past the exhaust valve seats. Now with new heads with hardened seats, all new head, intake and valve cover gaskets, I am battling high LTFT's. Got new O2 sensors on the way since mine have about 60,000 miles on them with raw fuel from misfires for who knows how long. Good news is that there is no sludge in the motor and the cylinder walls still have the cross hatch on them.

I see why it's pointless to further check for anything else than physically checking the valve train, thanks I learned a lot today.

I have the same problem cylinder 4 .sometimes it runs good sometimes it runs bad.but always cyl 4 .the car had a ticking noise after the head gaskets were replaced .so I replaced both rocker arms and lifters .i don’t know that it had a code p0304 before I replaced the rockers because like I said it had a blown head gasket .the machine shop said the heads and valves were ok .when they resurfaced the heads .so now I’m stuck with the cyl 4 misfire .compression test showed bad compression .bit some times it runs great .you nailed it for me .its a bad lifter ona new rocker assembly but more than likely a piece of some thing is blocking the oiling orifice for that lifter. Thanks a million your thorough diagnosis lead me to the only problem it could be .bad lifter or more likely a piece of silicone blocking the lifter orifice intermittently.now I can fix the car for zero dollars .

You’re a beast. Definitely completely thorough.

When you present on video I feel like you are talking directly to me very effectively. Thank you for All your videos S/D!

Gonna sub, not only for the great info, but I see you are still replying to comments today on a 5 year old video. Very rare and commendable. Much respect. Thanks.

it's a dodge caravan, it was beat when it left the dealer lot :))

In the past have found as the valve is turning a warped valve face will intermittently not seal properly. its usually thinner on one side on the exhaust valve side. I made this repair back in 2009 with a year model 1999 town and country /200,00 and its still running good today. My point to new technicians, be confident in your diagnosis and don't be afraid to repair instead of replace.

Good job sharpening production skills Paul.. your channel is just getting better

My 2000 Grand Caravan gave me 343000 km (215,000 miles) before packing it in. 3.8 L engine. There is no substitute for timely maintenance.

Send it to Eric, he loves those vans

I say broken exhaust spring, it sounded like it was alternating/cycling while running. the broken spring is riding up itself and dropping back off the other piece, probably broken near the spring base =p

Scanner "no sugar coating" Dan, well done again. Nicely explained.

Dont skip anything please i wanted to see how you connected that vaccuum gauge. Edit: I'm a fairly new mechanic with 3 years experience and these videos have helped me advance in my career. I look like the smart guy at work thanks to your videos.

Lifter problem wouldn’t be intermittent like that though. Intermittent sticking valve is my guess. Caused by binding valve guide, or weak valve spring.

Always gain something from your channel, thanks for sharing your knowledge. If you ever get the opportunity, I'd love to see your take on ECU tuning. Especially for a forced induction engine.

Stumbled on the channel today and it's awesome. Wife's 2008 caravan 3.3 has a intermittent cylinder 1 misfire. I did plugs and coil and it ran good for a day now the light is back on. I'm guessing I'm dealing with a lifter problem. Thing has 109000 and is a decent ride. When you first start it she idles a little rough but smooths out after a bit.

I had almost the same problem on a 2000 dodge G/C the only difference was the misfire was sporadic but we couldn't recreate the misfire over several months and 2 trips into the shop. 3rd time being the charm my customer brought it in when it was actually misfiring. For the misfire to surface they had to be on there way home from work with lots of stop and go traffic and the temperature was above 85 degrees and still intermittent. After checking spark and fuel that were good, it had low compression on cylinder 3 with a leak down test proving it to be a bad exhaust valve. After removing the heads we could see the issue which was a hairline crack in cylinder 3 exhaust valve. After watching this I started to think what the vacuum gauge would show while doing a cylinder balance test. Next time I get a misfire like this I'm going to have to look at this just to see if there's anything of value in it. Thank you for the great videos you always have great content.

Nice job. Trying to catch that with a compression gauge isn't easy. I've been trying to get the guys I work with to do relative compression test because it is so quick and easy to do.

Wife's van with the 3.3 is at 235K and still running great. A little rusty around the edges.

Everybody has their own favorite engine cleaning/flushing concoction, and this van would be a prime candidate for it! That intermittent compression issue is just screaming "sticky lifter" to me, and I'm all too familiar with the need to "keep it running" that commonly comes with vehicles in this condition. Idle it for half an hour with a quart of Dex III ATF (or other personal favorite), throw some fresh oil into it with a bit of [personal favorite], and ship that baby!

I had a few of these Vans and I had good luck got over two hundred thousand miles on both of them.

Always start at square one even if it had new parts and never assume the new parts are good. Found a bad brand new spark plug more than once.

The crusher is the appropriate fix for that vehicle....

You have a unique ability. Thankyou so much for all the help

Hey Paul, thank you for an another excellent learning video showing your technique of performing an on the spot diagnosis of an engine misfire through the process of elimination. While others may overlook, I also appreciate you taking the time to discuss the economics of maintaining an obviously beat up vehicle with a high mileage on its rap sheet vs looking at other viable options. This is huge. You just don't run a vehicle and expect it to work for you without giving the needed TLC. Wear and tear caught up with it and just feel sorry for the owner who probably was thinking that you could reverse it. Albeit, well done, my man.

Quick, efficient and effective. Time to move on. Great vid Paul.

At 3:37 Cylinder drop test. I had just replaced my coil with an aftermarket and the car was running no different than the old original coil. I did the cylinder drop test with a test light and after I did, the car was hard to start, but it did run once it started. Apparently I had damaged the new coil, so I put the original back in and it starts easily again. So beware, in my case this test damaged the coil.

Haven't been able to watch much since Hurricane María sent us back to the stone age, but now that I could watch this I have to thank youfor all your work. Shalom brother.

I run from people who drive a car for 150K miles with no maintenance and then want you to tell them what's wrong for free and fix it for $100 bucks.😕

Dude this save me wasting money on ignition coils and fuel injectors on my z3... thank you so much. I do engine work in the Pittsburg, Ca bay area.

Frommy experience it possibly has a cracked spring, common in my area. They break and allow a random recurring misfire on single cylinder. IF repaired repalce all vs seals and springs. BUT car is beat, the estimated price of top end pull apart ie vc/intake/etc tell them to take repair costs and old car and trade on different car AFTER having car given an extended vehicle inspection with test drive.

I had to learn something before I could learn from your content. Thank you and Schrodinger!

Great video man. Thanks for sharing your knowledge. I wish if i could use my pico as good as you as im currently trying to find an intermittent missfire on an almost new engine

Thank you for sharing your skills and video,you are the best diagnosis master.

Absolutely brilliant! Great job. Very impressive.

Nice find Paul. Gravy :D!

I have that same problem on my 3.6l pentastar!i think you just solved my problem!i will keep you updated.Subscribed!

Picoscope should hire this guy to run a lab class for them. I have this similar issue with a 5.7L tundra. Compression jumps around and vacuum steady although I did notice very small needle vibrations once in awhile. Wet and dry compression tests very inconsistent but I don’t think rings will cause that, I’m leaning toward valve issues of some kind. There is no noise like this one where it sounds like a lifter is being beat to death. And same issue across all cylinders.

Paul, please consider a video outlining requisite diagnostic instruments for HOME mechanic, including affordable scan tools. Thx

Super! Never a sync done on a waste spark system. Thanks!

Valve spring broke have seen this before intermittent missfire

omg i died @ butt face thank you for making my day

I know this is an old video but I gotta ask, why not do a cylinder leakdown? If nothing else it would eliminate culprits

I had a dodge minivan with a 3.8 many years ago with a very intermittent misfire on cyl. 3 that it took months before they could get to the shop with it still miss firing. It turned out to be a cracked exhaust valve on cyl 3.

i totally understand the conclusion a hydraulic lifter would be the only component in a valve train that could fluctuate but how you got to that conclusion is way above my tiny brain, inverting 6 to diagnose 3 or whatever you said, for me it's simple, it's a Chrysler, lift up the radiator cap and roll a new car under it....

I just realise today that Ericthecarguy signed off about 3 months ago from uploading videos. I don't want the same thing happen to you my friend. Stop working too hard brother otherwise you will disappear too. I really want to share your videos with my friends and families but I am scared if they get better than me in this field. You are really an intelligent man and I love your work. I hope you don't be a stranger to us.

I went through all the checks on a Jaguar x type. Had a misfire on 3. #, is on the firewall side and underneath the intake manifold. No way to access the coil or injectors without removal of the intake. Fuel checked out, Fuel trims out of whack, no vacuum leaks. I broke down took the intake off and removed #3 coil....as I removed it, I noticed a drop of water...I looked in to the tube and saw that the SP tube was 1/2 filled with water! took the rest of the coils off in that bank and the same thing! Not sure where the water came from, but I'd changed the intake Man gaskets a couple of weeks before and cleaned the area with degreaser, and rinsed. I thought I had thoroughly covered EVERYTHING with plastic. Car ran well for about two weeks, then the misfire. I bet it was running on 3 cylinders! Anyway, I dried everything and engine is running like a top. However, I'm still leery and wondering if there is a water passage on the head that is seeping. The "water" was not antifreeze as far as I could tell. I'm hoping that maybe it's water leaking down from the windshield washer nozzles or that maybe I didn't cover the engine as well as I thought I had and it took a while for the water to interfere with the plugs.

Some great comments but I think a lot of you missed where he said it runs fine on test drive. That points to lifter, not valve spring. Though I have seen a burnt valve produce similar compression results. Keeping in mind that the valve rotates in the seat as it opens and closes, and can produce intermittent bad compression.

Nice troubleshoot Paul!! As always~ That's a tough call on this one. But face 😂

Like my Verus Pro...graphing shows you so much

2:11 - I thought coolant, engine, and transmission leaks were just a standard feature on Mopar vehicles. Lol. *Just a joke, Mopar fans!* Nice video, thanks for the helpful information.

You are amazing, your knowledge is exceptional.

Thanks,that is VERY nice; then it becomes guessing; need a compression test, with the old compression gauge, oil in the cylinder (don't think it's needed here, lol), and valve cover off.

Not that it could be related to this case. Had a 2005 Chevy w/ 3800 v6. Misfire only at idle. Checked fuel/spark and that was fine. Checked compression on all cylinders and got the same numbers within 10%. Stumped, I had to go into the engine. One of the cam lobes was slightly worn causing a misfire only at idle. Car ran perfectly over like 1200rpms.

Great diagnostics!! I'm so glad I don't work on those crappy Caravans anymore. Oh wait, gotta fix one next week....ugh. Well, it rare that I have have to fix them. Better than the Ford Aerostar, those uber-suck.

Very comprehensive video, thanks for the information

Which is why you diagnose before throwing parts on something. No way is that thing worth fixing, but you're already in plugs, wires and a coil. Only thing maybe worth doing is telling the customer to try running a flush or some kerosene/ATF through in case crud in the engine/oil is jamming the lifters or something. Kill or cure. Might just be worth it if it goes another year or two before blowing up. Nice example Paul! Stay frosty!

Just bought 2007 dodge caravan sxt 3.3v6, seller said runs great, thing has been misfiring since i bought it month and half ago, shakes runs rough, gets a little better when warmed up, sounds like noisy lifter possibly clacking once warmed up only 102k on that one im driving now, gotta get it looked at runs like crap, shocks were bad replaced, struts are on the way out. I did all the plugs wires coil pack, changed power steering resevoir and fluid, changed air filter, cleaned mass air flow censor in air intake to throttle body with mass air flow sensor cleaner, removed throttle body and cleaned it and cleaned the idle air control valve of carbon wasn't to bad. No help van still runs like crap idles rough, the whole engine shakes when driving, no codes. engine is visibly shaking some when just idling from cold start up to, seems idle better parked after warmed up but then it has that fairly audible clacking sound like lifter or something. I could do pcv valve and egr valve..and other stuff like thorttle position sensor, map sensor but really i think its probably in the engine the prob, I hope not. FIrst guys i brought it to muffler shop said it runs fine, so um they were way wrong of course so i gotta bring it somewhere else where they going run real tests on it like this guy. I did notice when i changed the plugs that cylinder 6 on right front part looked dark like had oil or carbon build up on it for first half inch of the spark plug the other 5 cylinder spark plugs looked clean. Also the air conditioning condenser thingy when air conditioning on sometimes the whole muffler system shakes guess that could be on way out, overall i'd say most other things on the van are in good condition.

I have a 2000 accord and its misfiring .. Took it to the shop they say they cant find the problem

Thanks a lot Paul for the quick response and great explanation. Appreciate Artie

While the engine turning since the valves also turn, maybe carbon deposits sometime dont let the valve close all the way!! 😏 Great video Paul!

I wish to have this level of expertise...

Yes I would do work I personally own 2 of these it sounds like basic maintainable maintainance has not been done. The breaking issue is caused by heat warp unfortunately meaning with these and many other minivans you have to turn or replace the rotors every 6 months to a year. At this point it is a bit of an uphill battle its still cheaper than a new vehicle and if you are in need of something such as a caravan then its one of the better options.... Side note may recommend an odyssey just for the lower maintenance requirements.

Scanner danner is in another level☝

05 dodge grand caravan sxt 3.8L 270k miles I just replaced all new seals ,injectors ,spark plugs, .. put all back to gather now misfire#5 .. (going to the shop).. but hey at least it don't leak and gas in oil not mixing .. always got to stay positive..

Good thing you qualified that POC comment. I drive a an 02 T&C Butt let's face it, it's another good won professor. Soooo .... Thumbs up. Tell the guy to do oil changes more often than 20 30 thousand mile intervals. Oh and nice partial view of God's country in the background at the end of the vid.

Soooo, the number 3 was losing compression intermittently but (face) with a regular frequency? Which would indicate that the hydraulic lifter is collapsing? I don't get it Big Dan.

Valves rotate as the open/close. I would definitely check the exhaust/intake. There could be a seating issue that comes about as the valve rotates. Of course, could be a lifter or something else. Could be a valve sealing issue though.

A simple compression tester would have probably told us the same thing. If it was mine I would pull the valve cover off and take a look. If I had to pay a mechanic for his time I may have a different attitude about it. My guess as was mentioned earlier by someone else is that it probably has a broken valve spring which should not be that hard to replace if you can get to it.

Nice one. Not including what happened to this gem of a vehicle, is borderline cruel...

Sounds like the car needs to go to a vechicle rest home for the rest of it's life. All good stuff Excellent.

Hydraulic lifter getting gummed up from lack of service most probably. Get some paraffin in the oil, run it up for about a half hour then oil n filter change.

Hmm, it may have started due to the insulation of that injector at that cylinder. It's always happens at cylinder that is closest to the firewall.

learned alot about the picoscope great vid very informative

Great video Paul, I'll be definitely watching more, I believe I'm hooked.

Hi Mr danner yes everything is good now. Since I logged in with me and my wife's Facebook account lol. But everything is good now and happy I will see you're very good videos you're the best teacher I ever had. Big THANK YOU MR. DANNER and to you're son that he's helping you do the videos say hi to him for me thanks .

Girlfriend's Jeep was a mess random and o3 04 06 cylinder replaced coil rail plugs and new injectors used a good motul engine flush and my God did that help the sludge cut free and she runs good have not had a code since

I cant say how many cars ive had that caused an intermittent missfire even after i did everything to them. sometimes i would hear a slight tic noise, happened on my chevy tahoe with a sbc, 1 other wierd thing i noticed was if you slightly touched the throttle and held it, the rpm needle would stop and go stop and go through the sweep, replacing the lifters solved it, now my best educated theory on why a lifter would do this is accessively worn lifter tolerances, becoming even worse as rpms increase the lifter will collapse more and reduce camshaft duration as well as lift, and late valve timing events, theres just no way you could ever catch that on a compression tester snce it reades the maximum compression that cylinder produced, and not individual compression cycles produced.

I'd try some seafoam in the oil to see if it frees up. Maybe a top cylinder clean if carbon is suspected.

I did not get how you were able to graphic individual cylinders compresion on your scanner tool

im bending in dust, god damn your a good mechanic... best regards from a vw/porsche mechanic in denmark

Hi Danner , please explain the tools you used and what they do , how you use them ? You were so quick in using your tools without any prior explanations ... Thanks ..

Excellent call

Nice Troubleshooting skills!

Paul I recently purchased a Pico 4425 kit. It is awesome by the way. I enjoy your videos and I am learning quite a bit from them. Quick question, I noticed the spark event was after TDC, do you recall if there was a timing issue? I was just wondering because I am not sure if I was looking at it properly. Thanks for all of your hard work.