2000 OBW 70k mi.

 

This weekend while driving on the freeway I turned on the AC for the first time and I noticed a slight shudder from the car. Once the button was pushed the car ran like normal; when I turned the AC off it shuddered again.

 

Is this normal for these cars? None of my other vehicles have ever done this. It's almost like the alternator is underpowered or something.

 

Everything is stock (even the battery), in fact that brings up a second question; just before my 85 GL EA82 wagon blew a head gasket I bought a brand new battery for it. Do you think this battery will work in the OBW?

Shudder? Your loading up the engine, so a rpm drop then recovery is normal. Otherwise i would clean the IAC.

 

 

nipper

The battery should be fine as long as it fits in the car.

 

The shudder is the a/c clutch engaging not the alternator. It takes a second for the idle to kick up after you turn the a/c on. No big deal.

Hm.....I have an '00obw too and I'd have to say on the freeway driving as you stated I don't really notice the a/c compressor cycling, at least not a shudder like you stated. Maybe the compressor is having some issues and requiring more input shaft power to operate than normal?

 

Do you think the a/c belt is slipping? I've had that happen on my '96 suby and it'll squeak a bit until the compressor starts rotating, but it robs like 50% of the power for a second until it does start rotating and is very noticeable.

Shudder? Your loading up the engine, so a rpm drop then recovery is normal. Otherwise i would clean the IAC.

 

 

nipper

 

What's the IAC???

 

and BTW, when I say "shudder" that sounds really worse than it is. basically when I hit the AC button I can "feel" the AC pump, or clutch or whatever it is, engaging. It's felt through the engine which is transfered and detected as a slight bump, or, well... shudder through the rest of the car. I almost wouldn't notice it except that it happens as a result of engaging the AC (press button, car shudders). Today I turned it on and my wife even said, "What was that?".

 

If it's normal it's normal and I wont sweat it. I've just never experienced that with any other car I've owned...

IACV is idle air control valve. It can get gummed/crudded up with carbonaceous stuff, as can the throttle butterfly. Doesn't hurt to clean this stuff with throttle body cleaner (not anything that says only 'choke cleaner').

 

Not sure the IACV would cause an issue at freeway speeds, though I think the air to atomize the fuel from the injectors might still come from the IACV irregardless.

 

Rough IACV location is shown from my '96 2.2L below; '00obw is similar location:

What's the IAC???

 

and BTW, when I say "shudder" that sounds really worse than it is. basically when I hit the AC button I can "feel" the AC pump, or clutch or whatever it is, engaging. It's felt through the engine which is transfered and detected as a slight bump, or, well... shudder through the rest of the car. I almost wouldn't notice it except that it happens as a result of engaging the AC (press button, car shudders). Today I turned it on and my wife even said, "What was that?".

 

If it's normal it's normal and I wont sweat it. I've just never experienced that with any other car I've owned...

 

Just for the heck of it, check the motormounts too. Otherwise what you describe is normal.

 

nipper