Hey all, I feel like this topic has been beaten to death, but I figured I'd post another thread to make sure I'm not needlessly spending money. I have a 2010 SHO with around 98k on the clock (owned since ~60k). Recently I've noticed a problem where it'll sometimes shudder and fluctuate RPMs under certain circumstances, mainly when trying to accelerate on the highway. Before it downshifts, it'll shudder real bad and the RPMs will bounce around a little. It feels a lot like a misfire from another car that had coilpack issues, but there's no CEL.
It seemed to go away for the most part, but then I got the power pack from Torrie at Unleashed. I applied the tune, spark plugs, and thermostat and the problem has come back worse than ever.
Today I drained about an ounce of oil-ly goop from the intercooler, but that didn't seem to help anything. I've monitored torque converter desired slip vs actual slip with Forscan, but there doesn't seem to be any deviation that correlates with the shudder. At this point, I'm leaning towards the PTU. I haven't had a chance to have someone check the TSB out on it yet.
Like I said, I'm thinking it's the PTU but I thought I'd get some second opinions before I start spending money needlessly.
Purely a guess but what are your Boost pressures like ? It might be a BOV/Wastegate issue.
I haven't logged it but it seems to hold fine. I saw some other post about bad gaskets, I'll check those anyway.
BOV gaskets were fine. I pulled and check all six spark plugs; two of them the ceramic disintegrated as soon as I took it out of the socket. Replaced those two, checked gap on the rest and reinstalled. I was unable to replicate the problem on a test drive, all seemed fine. Hopefully it stays that way.
That is good news sort of.
What plugs were in there ?
They were all NGK LTR7IX-11 6510.
hmmpf. Not to bag on NGK But I also had two different sets of NGKs fail i less than 20k miles. Went back (then) to the 542's and only had fouling issues from then on (to cold a plug for my 2010 non-pp)
Quote from: TopherSho on June 26, 2020, 11:37:16 AM
hmmpf. Not to bag on NGK But I also had two different sets of NGKs fail i less than 20k miles. Went back (then) to the 542's and only had fouling issues from then on (to cold a plug for my 2010 non-pp)
I agree as AJP said keep the OEMs in on regular tuned cars without extreme mods.
I'll keep that in mind. I've put another ~200mi or so on them without any issues. I'll check them again in a bit and see how they're doing.