This 2001 Jeep Wrangler 4.0L is on its second engine at 379k miles.
According to the owner, it runs like GARBAGE…especially at idle and under acceleration.
It did make it to PHAD under its own power from 4 hours away.
Local shops have been STUMPED after replacing spark plugs and coil pack didn’t fix anything.
Cranking it over, sure sounds like at least 1 cylinder is very low on COMPRESSION…
Let’s diagnose this Jeep 4.0L and see if it can be repaired, or if it needs ANOTHER engine?!
PHAD PRESSURE TRANSDUCER:
http://www.pinehollowdiagnostics.com/phad-pressure-transducer.html
IVAN’S PICO WAVEFORMS:
https://drive.google.com/drive/folders/1k2j1qbvoP3x6M_QAaavJNcTtmCIta66l?usp=drive_link
TESLONG NTS 500 BORESCOPE:
https://www.amazon.com/dp/B07SQ4FLYX?linkCode=ssc&tag=onamzpineholl-20&creativeASIN=B07SQ4FLYX&asc_item-id=amzn1.ideas.BH34H8T28VY4&ref_=aip_sf_list_spv_ofs_mixed_d_asin
THINKTOOL PROS:
https://www.amazon.com/dp/B08XXWHQVJ?linkCode=ssc&tag=onamzpineholl-20&creativeASIN=B08XXWHQVJ&asc_item-id=amzn1.ideas.NHZL00NIDEPF&ref_=aip_sf_list_spv_ofs_mixed_d_asin
Enjoy!
Ivan
![Pin It](javascript:imwb_socialpress_window_open('http://pinterest.com/pin/create/bookmarklet/?media=https://i.ytimg.com/vi/C9sHlnsrJhk/hqdefault.jpg&url=http://carfixdiy.com/diy-car-repair-videos/jeep/jeep-4-0l-runs-like-garbage-part-1-diagnosis/&description=Jeep 4.0L Runs like "Garbage"? (Part 1 – Diagnosis)')){kind=link}
Can;t you use the CKP sensor for syncing the relative compression test?
You said they already replaced the motor. Was it a junk yard motor or a rebuilt from a reputable company? If it already is having a problem it wasn't from a reputable rebuilder then. There has to be a warranty on it if it's a rebuilt RIGHT ?
Thats got leaking valves. Oh dear, receded exhaust valves is my guess. Another Just Empty Every Pocket 4.0
what the heck is that white stuff?? san jose ca aint got that stuff..my 21 year rolla has zero rust. original exhaust try that
I do car my own repairs (as a DIY), and occasionally for family only. My standing rule is, if the the fuel tank is empty (or battery is spanked), I charge $25 labor, plus gas. (PS: I otherwise, don’t charge labor for family, and won’t work on anyone else’s cars).
one plug should be enough for the transducer as a sync
I love to watch your methodical step by step diagnosis and explanations. Always learn something.
Synch can still be used by pulling a spark plug and use in-cylinder pressure transducer alongside RC. Then with firing order identify the weak ones.
What is it with people's obsession with bringing the car to the mechanic with zero petrol in the tank It's silly
Retired now but it was common to see exhaust valves receded that far or further on cast iron heads running on LPG in the days of leaded fuel. LPG has no lead, hence valve seat recession caused by "welding" of the valve seat to the head with no lead to intervene. Over time the seat material goes out the exhaust pipe and the valve becomes recessed. The ticking that goes with it is the valve clearance in the "lash" of hydraulic followers running out of clearance. Usual cure was to put inkonel or other hardened valve seats in the head and stainless or inkonel valves in. Since introduction of unleaded fuel and aluminium head the seats are induction hardened or in aluminium heads, hardened inserts.
Glad to hear the customer approved the repair.
Rain or shine or snow, Ivan gets it done. I couldn’t help it. I’m a mailman.
I know these old Jeeps were infamous for dropping valve seats. Usually brought on by overheating issues. The Jeep Liberty with the 3.7 V6 had a bad rap for that. But when a valve seat drops out, mass destruction follows. I'm not seeing that here. So, did this valve seat pound it way deeper into the head? Or did it just burn it away? Ivan, I hope you take us along on a tear down. I'd really like to see what happened here.
Its a bitch to get those bottom intake bolts out!
Just put one of these 4.0s in a 2002 wrangler!
Just by looking at it the way the camera was it looked like that valve was to small as if it was replaced with one that’s not for that jeep
There is no reason to to have a Part 1 video that is 18 minutes long and put out Part 2 the next day, which you will do.
I would have been so disappointed (and shocked) if the owner didn't authorized you to do the repair.
They couldn't have dropped ten bucks of fuel into that thing before dropping it off?
That cranking sound and those codes, yikes. Cylinder 1 low compression…That's my guess at 4:21 in. 🙂
Did someone redo that head already and put an undersized valve in it? Not sure how a valve that otherwise looks ok could sink below the head surface. I'd love to see the valve train on that particular valve. Almost like a rocker slipped off but that doesn't fully explain the valve bypassing the seat. Even with a working valve in cylinder 4 that head still wouldn't run too great given those other cylinder pressures. Hopefully a valve job solves the compression issues and it isn't leaking/stuck rings. Thanks for the video Ivan, always love to see a new PHAD's post.
I am floored that people will travel hours to see you and yet can't put a drop of gas in their car for testing????? Don't they watch your videos? You are a trooper and I hope that you charge them double per gallon for the fill up (LOL I know that you wont but you should)
Great videos as always
This customer definitely has disrespected you with the gas BS. But he had no one he trusted to fix it, other then Ivan. Lol
wonderin' why you don't use a differential leakdown tester set up?
378 on the clock… The machine is a trooper.
I haven’t seen one of those in a while. You can tell it was driven like that for a long time.