Hey guys, my 2000 mustang v6 is my daily as I build my other car and enjoy it on nice days/weekends. It has 79k miles on it. Recently I've been experiencing a rough idle along with an occasional hard cold start. Well last weekend it started chirping/squealing in the engine bay and came out to be the camshaft synchronizer. Anyways, I thought that would have fixed the rough idle but it hasn't. I have replaced the fuel filter, I use mobile 1 full synthetic extended performance, shell 87 for gas and have recently used seafoam through the gas tank and vacuum line and fuel pump is good. Before I go spend money on new parts taking a guess every time I change something out, do you guys have any idea of what it could be? Sitting in the car it feels like I have a small cam in it. That's how the rough idle feels.

Thanks

 

Checked the IAC? Does it surge or get worse with the AC on? Blow a little carb cleaner on/in the IAC.

LINK

 

No I have not. I'll try that next I guess. I did have it at my shop a while back for rough idle and occasional hard start and they couldn't find anything. They said it may be timing related.