Jeep Cherokee Misfire / Skip / P0300, P0306
video description
Date: 2020-08-05
Related videos
Comments and reviews: 10
Wilson
Grand Cherokee Laredo 4. 7 2000 - After replacing radiator, passing checks then doing deeper diagnose- Turns out (constant P0307) (and intermitant P0302) after extreme overheat situation,
cylinder #7 compression is 30PSi and doesn't climb after reset gauge to 0.
Compared to others (80's+ PSI. Don't see off the bat any effect on radiator fluid (cap off) while running, no bubbles or overflow (doing it solo.
However, spark plug has tar like buildup within 20miles. At this point; assume either rocker/ lifter popped, Cylinder O-ring is bad, head cracked when overheated.
Can I pull the head without major hassle? Should I. Gasket seal is a scary thing.
Trade in time? What are your thoughts? Thanks.
reply
Grand Cherokee Laredo 4. 7 2000 - After replacing radiator, passing checks then doing deeper diagnose- Turns out (constant P0307) (and intermitant P0302) after extreme overheat situation,
cylinder #7 compression is 30PSi and doesn't climb after reset gauge to 0.
Compared to others (80's+ PSI. Don't see off the bat any effect on radiator fluid (cap off) while running, no bubbles or overflow (doing it solo.
However, spark plug has tar like buildup within 20miles. At this point; assume either rocker/ lifter popped, Cylinder O-ring is bad, head cracked when overheated.
Can I pull the head without major hassle? Should I. Gasket seal is a scary thing.
Trade in time? What are your thoughts? Thanks.
reply
Dodd
Thanks for showing us how to do it!
Now, roll in bearings, pull the head and get a valve job, ball hone the cylinders and install some sealed power pistons and new cam and lifters only if needed, add timing set, already have new oil pump, in under 500
Will restore compression and maybe some oil pressure will run like new for years easy, keep running rotella, they need it anyway for the cam
Or spend another 1000 and build a 4. 6
reply
Thanks for showing us how to do it!
Now, roll in bearings, pull the head and get a valve job, ball hone the cylinders and install some sealed power pistons and new cam and lifters only if needed, add timing set, already have new oil pump, in under 500
Will restore compression and maybe some oil pressure will run like new for years easy, keep running rotella, they need it anyway for the cam
Or spend another 1000 and build a 4. 6
reply
Bryce
I had this happen to me this morning after heading to work, I will be looking to work on this tonight. Thanks for doing this video and giving good explanation of the procedures you did.
I can give you some info on the low oil pressure. It's the head. if the head has the 0331 casting number on it then it has small hairline cracks between cylinder 3 and 4. In late 99-01 the 0331 head was used and then in 02 a different head was used.
reply
I had this happen to me this morning after heading to work, I will be looking to work on this tonight. Thanks for doing this video and giving good explanation of the procedures you did.
I can give you some info on the low oil pressure. It's the head. if the head has the 0331 casting number on it then it has small hairline cracks between cylinder 3 and 4. In late 99-01 the 0331 head was used and then in 02 a different head was used.
reply
Daniel
Just something I noticed in the diagnostics. The 'CYL6 MISFIRES' maxed out at 255.
That's probably because of the old 8bit electronics - 255 is the biggest number you can count with 8 bits.
If something reads 255 my guess is the actual number is bigger and growing.
Not sure - but makes sense to me; )
The largest number you can represent with 8 bits is 11111111, or 255
reply
Just something I noticed in the diagnostics. The 'CYL6 MISFIRES' maxed out at 255.
That's probably because of the old 8bit electronics - 255 is the biggest number you can count with 8 bits.
If something reads 255 my guess is the actual number is bigger and growing.
Not sure - but makes sense to me; )
The largest number you can represent with 8 bits is 11111111, or 255
reply
Patrick
I've never seen a coil like that, I have a 98 grand 4. 0 and occasionally it stumbles in low rpm and after a few minutes of driving and pumping the gas to keep speed up it at tight end up, I replaced plugs but not the coil a year ago also the air flow and idle sensor both sensors aftermarket. Thanks for this lesson
reply
I've never seen a coil like that, I have a 98 grand 4. 0 and occasionally it stumbles in low rpm and after a few minutes of driving and pumping the gas to keep speed up it at tight end up, I replaced plugs but not the coil a year ago also the air flow and idle sensor both sensors aftermarket. Thanks for this lesson
reply
Heywood
4. 0 Liter I-6 has a reputation for being bullet-proof. Or at least in my experience. When I traded mine in, it had over 400, 000 miles on it, only went through 2 water pumps, a serpentine belt, and I blew the harmonic balanced off of it somewhere around 320, 000 miles. Anyone else have a good experience?
reply
4. 0 Liter I-6 has a reputation for being bullet-proof. Or at least in my experience. When I traded mine in, it had over 400, 000 miles on it, only went through 2 water pumps, a serpentine belt, and I blew the harmonic balanced off of it somewhere around 320, 000 miles. Anyone else have a good experience?
reply
ebrandon98
1999 Jeep Cherokee Police Package 4. 0L 6 HO, milage unknown, no code for misfire but, it has a random miss.
SINGLE COIL (have to say it loud because I've had tards tell me to check each coil pack. a couple were ASE certified. New cap, rotor, plugs, wires, and coil didn't change anything.
reply
1999 Jeep Cherokee Police Package 4. 0L 6 HO, milage unknown, no code for misfire but, it has a random miss.
SINGLE COIL (have to say it loud because I've had tards tell me to check each coil pack. a couple were ASE certified. New cap, rotor, plugs, wires, and coil didn't change anything.
reply
tractor
Never seen all the coils on a rail like that before I guess it's quick and easy like other people sad but I kind a like individual cold packs you can just replace the one that's not firing makes it kind of easy interesting how they built that one though, good Job as usual thanks!
reply
Never seen all the coils on a rail like that before I guess it's quick and easy like other people sad but I kind a like individual cold packs you can just replace the one that's not firing makes it kind of easy interesting how they built that one though, good Job as usual thanks!
reply
Knarles
Had 3 cherokees 2 95s and a 01 the second 95 had 345, 000 miles when the salt got hold of her. Original engine, original trans. Keep fram filters out of the engine bay and theyll run forever & best part no timing belt. cough 4. 0 Toyota motor cough cough: )
reply
Had 3 cherokees 2 95s and a 01 the second 95 had 345, 000 miles when the salt got hold of her. Original engine, original trans. Keep fram filters out of the engine bay and theyll run forever & best part no timing belt. cough 4. 0 Toyota motor cough cough: )
reply
Scotty
There is this misconception with these 4. 0 coil rails that 2 of them have to fail at the same time. I have heard (and now seen) this proven that one can fail individually. Thanks for the great walk through on misfire code and diagnosis.
reply
There is this misconception with these 4. 0 coil rails that 2 of them have to fail at the same time. I have heard (and now seen) this proven that one can fail individually. Thanks for the great walk through on misfire code and diagnosis.
reply
Add a review, comment
Other channel videos
