My chevy tahoe is very sluggish. It is especially slow when the air is on. Also, when the air is on and the car is moving slowly or parked, the engine shakes and makes noise. The car also seems to have an idle problem. It is worse when the air is on. Any suggestion on what could be the problem(s)

Ben

The compressor itself could be the problem. Unplug it right at the compressor and see if engine will run properly. Check for how the belt looks as in worn, loose or anything unusual? Has anyone touched the A/C system recently?

It may be that the engine is just reacting to normal load of A/C so you need to isolate it to rule it out,

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

Thank you for your reply. Nobody has touched the A/C system recently. I will unplug the compressor and see if the problem continues. Could the compressor make my car idle funny and feel sluggish?

Thanks,

Ben

The reason I asked about anyone messing with the A/C is that so many people see the "death kits" with claims for quick easy fix to all your problems and just pump in oils, sealers and refrigerant which can toast the whole system.

A/C uses a lot of energy when it works properly and when it's overcharged or a compressor failure it can stall an engine, break itself or the belt etc.

That load does affect the idle normally. It is compensated for by automatically raising the idle to cover that. You don't really notice it happening but it does and if anything about that system or excessive load will affect smooth idling of the engine.

Does the RPM drop a lot with A/C on?

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/