Rough starts and sputtering
So my i6 is a little under the weather. In the past few months, randomly, it has a very rough start, sometimes with a scraping metal sound. After that it runs ok. But its also become more and more rough went driving. Not in handling, but with the engine. Its like its sputtering. It seems the worst when the engine is cold or been running for a while. Once when I was in park with it running after a 3 hours drive, it felt like it was going to stall. Every now and then, while in idle, the engine revs up and down- but not a lot.
Here are some of the things that have been replaced:
All O2 sensors 3 years ago.
TPS: maybe 5 years ago.
Idle Air Control: 3 years ago.
Cranks Position Sensor this summer (pCoded)
Throttle body cleaned this summer.
New tranny cooler put in.
Spark plugs last year
Leak in oil pan fixed
No P codes. Mechanic is worried my head gasket is going to blow, but it really isn't showing those symptoms. I'm more worried about a fuel filter or fuel pump. Fuel filter was changed at around 100,000 miles. I now have close to 190,000. Mechanic also thinks my PCM may be going.
Any thoughts or ideas?
The only other wildcard would be that I started towing for the first time ever this year. And on a hot, windy hilly day, my 'Engine Over Trans' light came on. Pulled over, let it cool down for a few hours and have been fine ever since. Also replaced all the tranny fluid, and it runs much smoother now.
2004 Grand Cherokee SE i6 | 2" BB with Daystars and brand spankin' new Bilstein 5100s | Summut Racing slotted & dimpled ultimate performance front rotors and power stop ceramic pads | JK Rubicon wheels w/ 245/70/R17 General Grabber AT2s