Rough idle

[jshannon]

I have a 2003 Pilot with 107K mileage. On Thursday I had work done including replace timing belt, water pump, hydralic tensioner, "tune up" to replace spark plugs, transmission fluid, engine oil/filter. It ran fine until two days later when the malfunction indicator light came on and later the VTM-4 light. The idle turned rough and there was vibration (off and on) in the engine when accelerating. The engine vibration goes away when with letting off gas or canceling cruise control. The gas mileage was affected significantly. EGR valve replaced in 2007.

Could this engine vibration/rough idle be due to the recent work or a new problem (O2 sensor or other)? Thanks for any info.

[theirishscion]

Well, get the code read immediately for sure, but yes, given the proximity to the timing belt job, I'd say it's entirely possible that the timing belt skipped a tooth or three. I'd take it back to whoever did the timing belt and raise a stink, and I'd do it quick before it slips another tooth and starts bending valves. Of course, it might not be that at all, but better safe than sorry in this circumstance.

[rocky]

I would also suspect a damaged engine mount. Especially since the vibration disappears when you lift off.

[jshannon]

Thanks for your suggestions. Going to Autozone for codes and will give updates.

[jshannon]

It is a P0300 code
Definition: random cylinder misfire detected
Probable cause: fuel system concern, ignition system concern, MAF sensor faulty, heated oxygen sensor/air-fuel ratio sensor fault, blocked intake or exhaust system

[jshannon]

I took it to the same place that did the original work. Within 30 mins they were finished and said it was a vacuum cover that had come off. It was put back on and the car seems fine.

[mclairmo]

Problems that happen soon after work was done is usually caused by that work. Always take it back and have them check it out before assuming something new has broken.