Since I seafoamed my car about a week or two ago my car is running great and is more responsive. over the past few days while I am driving and start accelerating moderately the engine will rev high and then drop down like nothing happened and won't do it again. It has happened only 2-3 times over several days and about 10 long drives(20miles+) but has me alarmed. I assume it is a misfire and my spark plugs are fouling from the seafoam. I have Denso iridiums and about 30-40k on them now, so it is time to change them anyway. I just ordered a set of NGK iridium IX plugs(I don't think Denso's provide any HP gain at all) hopefully when I install them everything will be fine. My question is do you think it could be something else?

 

Does it rev high then drop while driving or just at a stand still?

 

only when driving and accelerating moderately. there is no CEL yet either.

 

So the revs actually go up and drop while driving? Is it a fast many times in a row or just once?

 

just once, does not repeat itself either, car doesn't shift erractically at all when this happens its just like a little spike and then it goes away. revs go up about 1k and then back to normal.

 

"recommended to change sparkplugs after using seafoam" was posted all over the "seafoam'd the 'ol TL" thread. Maybe this is something to look at.

i seafoamed like 5days ago, but i have moderatly new spark plugs ~ 25,000mi on them

good luck.



*edit: Denso iridiums have a short life if i remember the old threads...unlike ngk...and iridium sparks itself have a much shorter life than platinum ones, just better conductivity.

 

that's what I figured. I already bought new NGK Iridium IX's a few days ago, should get them soon and I'll be replacing though along with timing belt and water pump, new front driverside wheel bearing being replaced, then mobil1 oil change, full alignment and an icebox. Gonna be a busy week for me and my car.