Cowhorn

I took my ISV off last night and have spent a few hours and about a can of brake cleaner trying to free up the metal valve which at this time is nowhere to be seen. I believe it is stuck completely open, and it isn't budging.

Is there another way to free it up? What does the mechanism in there look like?

If I reinstall it as it is, can I drive the car with it wide open like that?

Cowhorn

I'm free. Got it to go.

Mike J

How did you free it up? I have undone the screws to adjust it, but never have split it apart - might do that once I encounter a permanently frozen one though, and that was going to be my suggestion if nothing else worked.

How did the car idle/run with it stuck open?

Cheers,

Mike

Slow Guy

I've only had 1 that was that stuck when I took it out ('97 M3), cleaned it up real well but within about 2 months I was replacing the thing (it was stuck again). It's a good bit harder to get to on the I6 BMW, it's under the intake manifold, didn't want to do that a 3rd time so I replaced it.

Mike J

Is it the same unit on the BMW? If so, interesting to know.

Slow Guy

Don't know if it's the same part number but it sure looks the same.

Edit: On the AutoHausAZ site the 2 ISV part numbers are 2 numbers off (....43 vs 45) and about $45 difference. Guess which one's more expensive.....

1pcarnut

The BMW? What did I win???

matt777

ISVs do deteriorate requiring replacement. After cleaning mine it was still slow to react as compared to a new one. I have a LWF which makes the deterioration more obvious.

Cowhorn

Mike-

It freed up with a single shot of WD40 after using almost an entire can of brake cleaner on it first to no avail. The valve cleaned up nicely.

The idle was a little rough when both cold and warm, and it would shudder just a bit from time to time and drop rpm from about 900 to 800. Now that I have reinstalled the ISV it is still doing the same, idling at about 800rpm and occasionally shuddering and dropping down to 700, maybe 600 rpm. No stalling.

So what's my next step? Look at the plugs/wires? Distributor?

Ed Hughes

I'd say your next step is to clean the WD40 out of it. With the exception of being good at displacing moisture, its about the worst lube you can use. That stuff will leave a gummy mess, and put you back in the same spot.

Cowhorn

Yeah, Ed. I blew it out with more brake cleaner before I reinstalled it. The valve was loosey-goosey when it went back into the car.