Contour Enthusiasts Group Archives Forums General Troubleshooting Still bogging down/hesitating-getting worse!

Ok so here's the problem: Before the motor is heated up (before needle reaches 'N'), when you try to move anywhere the engine will bog way down, almost stalling, but it won't stall. I have to rev it way up and slip the clutch to get the car to move. After the motor is hot, it's fine, no bogging. Although it does seem to idle slightly rougher now, and the tach sits slightly above 500rpm at idle. The engine also doesn't seem to rev as smoothly as it once did. Recently someone suggested it was the egr valve, sounded like a good idea to me, so i replaced it. Didn't do anything. Spark plugs have been replaced recently, so was upstream O2 sensor. No CEL either, it's been bugging me for a while. Anyone please help!

P.S. what causes that slight clunking noise when moving slowly?

Mine is doing exactly the same thing, only when cold. If I force it to start moving you can hear a clunking noise that sounds like some hitting the exhaust with a hammer. Really wierd.

I'm thinking it's the IAC valve, but not too sure. Mine "sort of" does the 1200 to 800 RPM thing, but it's all I can think of.

Clunks from inside the exhaust manifold may be crumbled pre-cat elements. Use a mechanics stethescope (or big screwdriver) to listen for the source of the noise. When the pre-cats start falling apart the dust clogs up your exhaust and bogs down the engine. The cold engine bogging sounds more like an IAC or loose hose problem in the intake area. You still may have clogged up EGR ports behind the throttle body which can be cleaned with carb. or TB cleaner and a soft rag once the TB is removed. If the EGR gets really bad, it usually causes a CEL.

Time to pull the IAC off and clean it. It sounds like it is sticking. Two 7mm bolts and it is off.

-Lance

Thanks for the responses guys! I will try to clean or replace the IAC valve.