What BAD Compression Looks Like! Jeep 4.0 Compression Test

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[@Jarod1941]

If it's 2 or more cylinders adjacent to each other, that's more times than not a head gasket. Keep us updated. Great vid.👍

[@dissociativecat7495]

good point

[@MrMrsregor]

but could also be a crack in the head or block

[@moabwheeling]

Hey Dale, I forgot to mention in my last post that I ordered a Jeep Solid coffee mug. Yahoo !! Looking forward to my morning and afternoon coffee with it. Take care sir.

[@JeepSolid]

That's awesome! Thank you for your support.

[@05glisedan]

I've just discovered the same problem on our 99 XJ with 235k miles. Compression test results. Cylinder #1 160 #2 165 #3 50 dry - 60 wet (teaspoon oil added) #4 50 dry - 60 wet (teaspoon oil added) #5 165 #6 160 Waiting for leak down tester to arrive at auto zone. Either way, it seems head removal is in my future. Gonna check out enginetech, see what they've got. Also waiting for Russ Pottenger to reply with parts list and price for stroker.. Gonna follow your build closely..... Thanks for posting.

[@SE45CX]

One advantage of having a female assistant. She will never give you criticism on your test approach. You know, you put effort to make a plan for a proper test and the last thing you want is to have an adult male share his preferences on doing a compression test at that time!

[@tynado1173]

I like that you take the time to teach what I'm assuming is your daughter. Good man

[@steffenmanderla7631]

Add a squirt of oil to the faulty cylinder's as that will tell you if your valves are shot or the rings.

[@dustincmills]

How so?

[@moabwheeling]

Great video Dale and very well explained. Hopefully you will get a handle on the problem. I'm still leaning at a cracked cylinder head but we will see . Take care and be safe my friend.

[@JeepSolid]

Yeah, could be. We'll pull the head and see. Hope your procedure went well

[@dissociativecat7495]

use an air compressor put about 30lb of air on the cylinder , bad head gasket will leak air into the cooling system ,bad valves will leak air out tail pipe or throttle body, rings will leak air out oil fill and oil dipstick. both valves need to be closed

[@HaleMoana]

Great vid. And great channel. Good luck and keep ‘em coming.

[@trevorjenglish]

Awesome vid! Keep up the amazingly helpful work🙏

[@xlsizedburrito7682]

Exact same issue I’m having with my 95 ZJ I just picked up! Cylinder 2 got 15PSI and Cylinder 3 got 30PSI. Others were all 120. Replaced a bunch of things before thinking about compression… oops

[@garyradtke3252]

Forget about pulling things apart to visually inspect. Perform a leak down test. You don't need a gauge just an air compressor and the compression tester hose with the Schroeder valve removed and the piston on TDC compression stroke. Of the two cylinders with low compression I would bet you will hear air escaping from the adjacent dead cylinder and if not you should hear or feel it from the tail pipe, carb/throttle body, and or the crank case breather. The center cylinders are real common for the head gasket to fail do to overheat on inline and "V" engines. Some engines can overheat in certain spots but not be indicated on the water temp gauge since that just shows the average of the engine.

[@FlawedOffroad]

I need to do this, I have blowby but I haven’t tested how bad yet. I’ll cover that after I finish my axle swap

[@BuiltNotBoughtTV2019]

Thanks for the video. Again an awesome help for a rookie like me 👍

[@tomasdipagio]

Great Cliff Hanger!

[@JeepSolid]

Yep. Compression is very bad in those 2 cyl. I will be continuing the work on my live streams Wednesdays.

[@troybrake5686]

Sounds like bad valve or stuck, having that low compression should create a ton of blow by if it's rings, jmo!

[@blurglide]

Wouldn't it make more sense to remove all the plugs so it cranks faster? Also, why test it twice instead of just letting it turn over a few more times? It seems like the additional time would give the engine more time to cool down (as would having to remove the spark plugs individually)

[@shawnmaver797]

Looks like another rebuild video. I'm in. 😃

[@liaison66]

Wondering why you didn't do the wet test?

[@claycoates5056]

Head Gasket ? Did It Run Hot? is the coolant clean ? I'll be watching

[@nyleanderson5557]

How would you know if it’s a cracked head?

[@caseybanter]

What did the problem end up being??

[@ky0611]

What happens if debris falls into the cylinders?

[@trhmlton9293]

I have the same tester and can't get any of the adapters to thread in as the threads are deeper then the top of the spark plug hole. What size adapter are you using?

[@jeremysard]

Same issue! I was hoping to find that adapter in the tool list in the description. Any help @jeepsolid ?

[@ujayet]

I have a feeling my 4.0 liter is also running like a 4 cylinder.. I wonder how much it cost to get this fix🤔

[@JeepSolid]

This turned out to be a cracked head gasket. Fixed it myself fairly cheap

[@estearagon9199]

Video ?

[@jaredlowe1303]

Found this, after doing a compression test on my ‘93, and finding super low compression in 2 and 3, as well. What ended up being the issue with yours?

[@JeepSolid]

Blown head gasket between 2&3

[@JeepSolid]

Blown head gasket between 2&3

[@JeepSolid]

Blown head gasket between 2&3

[@jaredlowe1303]

I’m thinking that’s my issue. Pulled the exhaust and intake, today, going to pull valve cover and head within the next couple of days.

[@JeepSolid]

Haha, wow! Did my reply post 3 times? LOL😂. Not a bad project, just takes time.

[@billyj.taveras834]

The adapter where did you buy it?

[@jeremysard]

Same question.

[@MrJoey1570]

Was Sasha the music producer?!

[@JeepSolid]

Sounds like it, huh

[@NoWr2Run]

I thought this was going to be you taking your head off & showing what is wrong with ? Waiting for that vid. You already made a video like this before , just waiting for you to remove your head on your low compression engine TOO SEE WHAT HAPPENED TO IT. IS THIS PREVIOUS VIDEO ?

[@JeepSolid]

Yeah, you watched the live stream. This is the edited video of the actual test

[@leskobrandon538]

Nice millennial techno music...

[@JeepSolid]

Haha! yeah