PDA

View Full Version : Bouncy idle, cold air, dash lights



vaaccess
10-28-2006, 09:49 AM
Well...I just took my '94 E34 525 in and got whallupped with a $1200 bill to do some general maintenance as well as replace the front brakes (and rotors), replace a front fog light assembly, and replace the control arm bushings. Just the nature of the beast I guess. :)

Anyway, there were three things they didn't get to that I would like some input on.

1) Bouncy idle - While the car is warming up and even moreso on a hot restart, the idle will bounce from 400RPM up to 700RPM. It sounds like I'm using my foot to rev the engine. Once the car is running at normal temperature, it does not do it. About a year or so ago the previous owner had to have all the air intake part replaced becuase something got cracked and cold air was getting in and it was basically un-driveable...Now, what's interesting as I'm thinking about this more is that this problem has been going on for a long time...If there was a lose clamp wouldn't the idle be jumpy all the time? I was thinking it might be an O2 sensor going bad, but I'm not getting any check engine lights...

2) My rear air vents blows cold. In the winter time it blow super cold air, but when I'm running the AC I'm pretty sure it blows cold air then, too. Could there be a valve that is stuck and not letting any warm air get into the mix for the rear vent?

3) The lights that light up the temperature and fan controls on the dash work 1% of the time at most. I think I've seen them on maybe 3 times since I've had the car. Typically I'll hit a little bump or something and then they'll pop on, but it's unusual. Hitting the controls does not turn them on. Any thoughts on what I'd need to do to fix it? I haven't taken the dash apart on this car so I'm not sure it's worth attempting.

Thanks!!!

DaveVoorhis
10-28-2006, 10:46 AM
1) Bouncy idle - While the car is warming up and even moreso on a hot restart, the idle will bounce from 400RPM up to 700RPM. It sounds like I'm using my foot to rev the engine. Once the car is running at normal temperature, it does not do it.
Mine does this for about five to ten seconds only after a cold start. I suspect a vacuum leak or gummy idle control valve, but haven't yet investigated further. The intakes on the M50 engines involve a festival of rubber pipes and seals that harden, crack, and leak over time.


2) My rear air vents blows cold. In the winter time it blow super cold air, but when I'm running the AC I'm pretty sure it blows cold air then, too. Could there be a valve that is stuck and not letting any warm air get into the mix for the rear vent?
They're supposed to do that. They're fresh air vents. Warm air comes up from under the front seats. There's a picture in the owner's handbook that shows where cold, heated, and semi-heated air comes from.


3) The lights that light up the temperature and fan controls on the dash work 1% of the time at most. I think I've seen them on maybe 3 times since I've had the car. Typically I'll hit a little bump or something and then they'll pop on, but it's unusual. Hitting the controls does not turn them on. Any thoughts on what I'd need to do to fix it? I haven't taken the dash apart on this car so I'm not sure it's worth attempting.
Thanks!!!
Mine does that, too. I'm saving fixing it for a dull weekend. The control panel comes out fairly easily once the radio has been removed. The radio comes out with either odd screws that can be finagled loose with a Torx driver or suitably filed flat blade, or by sticking rods of appropriate diameter down four holes. Once the radio is out, the control panel can be freed by popping it out from the back on the left-hand side.

Felixdacat
10-28-2006, 11:32 AM
Possible cold start injector? Dirty ICV? could be the o2 sen. Possible loose or shorted connection on the lights?





Well...I just took my '94 E34 525 in and got whallupped with a $1200 bill to do some general maintenance as well as replace the front brakes (and rotors), replace a front fog light assembly, and replace the control arm bushings. Just the nature of the beast I guess. :)

Anyway, there were three things they didn't get to that I would like some input on.

1) Bouncy idle - While the car is warming up and even moreso on a hot restart, the idle will bounce from 400RPM up to 700RPM. It sounds like I'm using my foot to rev the engine. Once the car is running at normal temperature, it does not do it. About a year or so ago the previous owner had to have all the air intake part replaced becuase something got cracked and cold air was getting in and it was basically un-driveable...Now, what's interesting as I'm thinking about this more is that this problem has been going on for a long time...If there was a lose clamp wouldn't the idle be jumpy all the time? I was thinking it might be an O2 sensor going bad, but I'm not getting any check engine lights...

2) My rear air vents blows cold. In the winter time it blow super cold air, but when I'm running the AC I'm pretty sure it blows cold air then, too. Could there be a valve that is stuck and not letting any warm air get into the mix for the rear vent?

3) The lights that light up the temperature and fan controls on the dash work 1% of the time at most. I think I've seen them on maybe 3 times since I've had the car. Typically I'll hit a little bump or something and then they'll pop on, but it's unusual. Hitting the controls does not turn them on. Any thoughts on what I'd need to do to fix it? I haven't taken the dash apart on this car so I'm not sure it's worth attempting.

Thanks!!!

DaveVoorhis
10-28-2006, 11:52 AM
Possible cold start injector?
There isn't one on the M50. Cold start enrichening is done by lengthening the injector pulse.

vaaccess
10-28-2006, 02:45 PM
Ugh.

Yesterday when I picked it up it was rainy so I had the wipers on and the windows up and the radio on, etc.

Today is much nicer and had my windows down...And, what the hell do I hear? A metallic rubbing noise coming from the right front, I believe. Definitely changes with speed and doesn't stop when I depress the brakes. They clearly ****ed something up. Not only that, but twice now when I started the car and started to back up a whining noise that was pretty loud started coming from the front of the car.

So, I'm obviously taking it back in Monday with a vengenance. Now, my question is, should I avoid driving it today and should I make them tow it in?

Felixdacat
10-28-2006, 06:14 PM
Good to know. Thanks for the info. That helps me get to know this car also.

vaaccess
10-29-2006, 01:01 PM
Mine does this for about five to ten seconds only after a cold start. I suspect a vacuum leak or gummy idle control valve, but haven't yet investigated further. The intakes on the M50 engines involve a festival of rubber pipes and seals that harden, crack, and leak over time.


So, should I care? I mean, is there any negative impact of this "problem" in the long run? It really hasn't gotten any worse in the last year so I'm wondering if I should even bother to spend money on having it diagnosed and fixed...


They're supposed to do that. They're fresh air vents. Warm air comes up from under the front seats. There's a picture in the owner's handbook that shows where cold, heated, and semi-heated air comes from.QUOTE]

Whoa. Awesome. Glad to know that. Guess I should have RTMF. :D

[QUOTE=DaveVoorhis]Mine does that, too. I'm saving fixing it for a dull weekend. The control panel comes out fairly easily once the radio has been removed. The radio comes out with either odd screws that can be finagled loose with a Torx driver or suitably filed flat blade, or by sticking rods of appropriate diameter down four holes. Once the radio is out, the control panel can be freed by popping it out from the back on the left-hand side.

Hmmm...Maybe I'll take care of it if I ever replace the radio then or have some time to kill...