2001 Chevy Astro Van idles rough when stopped in gear. But not in neutral (

steveb17

2001 Chevy Astro Van idles rough when stopped in gear. But not in neutral (?).

My 2001 Chevy Astro van idles and vibrates rough when braking to come to a stop, and while stopped (in gear).

But if I slip it into neutral it idles out fine(?). I was having problems with my heat. So, I replaced the thermostat, flushed the radiator and added new anti-freeze. This helped to care of the heating problem; And, relieved some of the rough idle symptoms I've been experiencing.

Any ideas as to the possible problem for the remaining rough idle vibrations?

classictrucks

i have same problem in my 2001 astro van.i was told by mechanic it was motor mounts which made since because when in nuetral there is no load on motor.hope this helps.

tools4u735

Mine is a 2001 GMC Safari with similar issues. Has anyone searched for a service flash from GMC/Chevy about the motor mounts. I would think that this would be a serious safety issue if they are inferior in quality, and should be recalled and paid for by manufacturer.

darrelk

hi steveb17,
did you figure out what was causing the vibrating? my 98 just started doing the same thing. when im completely stopped with my foot on the brake the idle is really rough while in drive. if i go into neutral or park or reverse the idle smooths out. if i take my foot of the brake pedal while in drive with the emergency brake on(so it wont drive on) the vibrating stops. it only seems to be vibrating while the brake pedal is applied and the transmission is in drive. i would think if it were engine/tranny mounts it would vibrate in reverse too, but it doesnt. wondering if it could be caused by the hydro brake assist system, like a brake booster leaking vacuum??

darrelk

update: problem fixed. replaced transmission mount and completely fixed the vibration. part was $32 autozone #EM-2879. for some reason autozone list the LS part in there system wrong. my van is a 1998 LS but the transmission mount part i got to match my van was listed at autozone for the LT model. 15mm open face wrench, floor jack and about 30 minutes is all it took.

the way i figured it out: with the engine idling i put my van in reverse and it would stop vibrating, so while holding down the brake pedal i put it in drive and gave it a little gas, that way the induction system had a chance to start working (iac,egr...) without the engine being able to move. it did not vibrate. when it came back to idle. when i took my foot off the brakes and let the engine move the vibrating would start again. that told me the induction system was not the cause but that it was only when the engine "moved". motor mounts or trans mount. got underneath and was able to lift up the driveshaft about and inch and saw the tabs on the transmission mount were both broken.