Did a CCT, #4 and #8 cylinders failed. I have been chasing the cause of a rough fluctuating idle and an increase in engine noise when hot for some time. The engine runs smooth and is much quieter when cold. I first tested in neutral and it passed, tested a second time in drive as suggested by the scanners "testing tips" and it failed. I did not try and do a second test in drive to confirm the results because the engine was making so much knocking and rattling noise during the test. During the test it came very close to stalling twice. Would the most rational next step be a compression test? or? I would appreciate any advise. Mike
Failed cylinder contribution test
- Thread starter 70jeeper
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bad12jr
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Check and triple check all connection's. Pull the valve covers and inspect everything. Check injector oil discharge.
How many miles on the engine? Oil condition? Tapatalk doesn't show sigs so what mods?
Sent from my x2 chillin in the middle of no where
How many miles on the engine? Oil condition? Tapatalk doesn't show sigs so what mods?
Sent from my x2 chillin in the middle of no where
The motor has 121,000 and bought the truck new. The oil has less then a 1,000 miles and has been changed at 3,000 with two exceptions when it went close to 5,000. Mods include Tymar intake, 4" exhaust, SD intercooler, TW tunes, SRP1 HPOP and gauges.
JD3020
Active member
My truck idles nice and smooth when cold, and like a complete POS when hot. Can't figure the damn thing out. LOL Basically changed everything except engine mounts, a few small/random sensors, and the PCM.
But i'd go through and check out every plug and wire. Last week I helped on a buddies truck, where every UVCH, except 1, was burnt up up at a GP pin. One was bad enough that the plug was melted into the gasket, and it was shorting and cutting off an injector. May not be your issue, but wouldn't hurt to check.
But i'd go through and check out every plug and wire. Last week I helped on a buddies truck, where every UVCH, except 1, was burnt up up at a GP pin. One was bad enough that the plug was melted into the gasket, and it was shorting and cutting off an injector. May not be your issue, but wouldn't hurt to check.
superduty4x4
Member
Sounds like an IPR issue.
JD3020
Active member
Thats what i think it is as well. Only thing that makes sense to me at this point, unless theres an underlying issue somewhere else that heat is effecting.
But I think this is the 3rd IPR i've put in the truck, 2 used and i borrowed a new one back when i bought my truck and never noticed a change. But that was the old engine, which had uneven compression, haven't messed with my "new' one yet.
96OBS
New member
My truck is pretty smooth when idling but when its warm it gets a little bit of a lope and shakes the truck a little. I just look the other way.
Would like to look the other way but this is beyond a little lope not to mention it sounds like a Dodge (an old Dodge) when warm. Mine started out as a little lope but progressed into much more. This truck is not only my daily driver, I regularly tow heavy with it and have nightmares about tow bills for truck and trailer.
lincolnlocker
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do the #4 and #8 cct codes stay when you switch tunes?
live life full throttle
live life full throttle
Binder man
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My personal truck when my first set of injectors started getting some scoring would run awesome cold and get a slight lope if you let it idle for a bit when warm. That was the only time it was noticeable.
96OBS
New member
I normally won't even run my air conditioning because it has a very weird idle/lope. It may be normal 7.3 lope cause I was always used to a tight Cummins sound.......
