Alright guys well as the cold has begun to set in...my 2.7L has been giving me some trouble. It has 144000 miles on it and still pulls strong. However, lately I've noticed that the engine surges... only noticeable when you are driving and when the engine is cold. At idle it is fine and even reving it...its still fine.
I"m not sure what the deal is with it. I run Mobile 1, good air filter, fuel filter, pvc, spark plugs, wires look ok although I haven't replaced them in the 4 years of owning it (25k miles i've put on it). I have replaced the stock manifold because of a crack ...that was with a cheap one from ebay though.The TB look fine and so does the MAF although I went ahead and cleaned them anyways.
So, I'm stuck...I did a TPS check last winter when I first noticed it and it was fine. Its only when the cold months hit do I really start noticing and this year seems to be notably worse than last already so I need to get it diagnosed and fixed.
Could the plug wires or o2 sensor cause these symptoms? I'm also thinking it could be another manifold leak since the surging seems to go away once it warms up...still there but very slight...?
Please help!!
Kyle