High idle after timing belt change

[bichmgnt]

First post here but I've been around the online community a while. I also posted this on bimmerforums.

After doing a bunch of work on the car (91 325iC w/JC chip) started it up and it idles steady at 2K rpm. Valve train seems a bit noisy also but it might be my poor work doing a valve adjustment.

Timing belt change went pretty much by the book with no parts left over, not even a washer, and I didn't lose any tools (yay!). I did a lot more than a timing belt change (water pump, hoses, belts, etc.) and I did take the throttle plate out to clean it but that seemed to go back together ok with an even hairline of light all the way around the plate when closed (it closes all the way to the set screw). I also wrapped tape around part of the wire on the spark plug harness that monitors one of the spark plug wires and goes to the other side of the engine. The cover was damaged with about an inch of wire exposed. The wires still had their individual coating and seemed okay. Timing belt seems to be the one thing I have any real doubts about.

So questions:

1. If the belt is a tooth off could that cause high idle? I'm thinking maybe the car thinks the timing is advanced causing high idle. But I would have guessed it would run much rougher.

2. Could being one tooth off cause any damage? It seems unlikely that there would be so little tolerance for error.

3. What else might cause the high idle after the work I did?

I'm going back to check the valve adjustment although I thought I did a pretty good job at it. If it still has the high idle after that I plan to tear it apart and check the belt again. Hopefully you guys will come up with something.

All thoughts much appreciated.

Steve

[DaN]

A hairline of light all the way around the throttle plate?
That doesn't sound right. It's letting too much air in at idle.

[bichmgnt]

Alright, everyone can stop worrying about my car. :?

High idle problem fixed itself after a few minutes of running. The noisy idle was a loose power steering pump pulley (it was very late when I was doing this last night.) Anyway, tightened up the pulley and the noise went away and after running for a bit the engine seemed to run okay. I have a feeling the high rpm was due to new fuel filter and hoses having air in them and that air had to be purged before it would run right. That's my theory, anyway.

One problem remains - overheating. I put in a new thermostat, new fan clutch, new water pump, new radiator and all new hoses. There isn't much more I can replace. Heater runs cold as well. It almost seems as if there is a blockage somewhere but everything I looked at seemed nice and clean with no evidence of buildup. What's weird is that when I start to drive the temp goes down but not all the way to center and heat starts to come out of the heater. But if I stop the temp goes up and the heater goes cold. This was a problem before I did the work and it's a recent problem but it seemed to not be as severe before. Maybe the thermostat opened sooner.

Any ideas? Fixes? I'm think I'll make this a separate thread.

[EverWiser]

You'll have to bleed the air out of the cooling system...There's plugs/fittings on the T-stat housing for just this purpose. You can also loosen the housing itself and accomplish the same thing. Also, it doesn't hurt to fill engine with coolant/water mix through the t-stat housing before sealing everything up and running the engine....Just my .02...