Monday, September 19, 2011

'99 grand am, new engine..weird driving when engine gets hot?? help?

had a brand new engine put in about a year ago, now with 10k miles.

about 3 monthes ago, new ac delco plugs, wires, coolant, oil changed every 1,500 miles. well taken care of. car drives great!..

but... i notice when the engine gets hot, when you steps on the gas..it doesnt take off or have as much power as it did when the engine was cold... (when the motor is cold the car just launches when you step on it a bit).. but when it gets hot.. it doenst as much..... and every once in a great while, when your at a stop light and push the gas it has a tiny bogging.....for once for a tiny tiny bit.. and then its good.im not really sure how to describe it sorry guys lol... but yea is this normal for an engine to not have as much power when it gets hot???..



another question. every once in a while on a cold or hot start, right when you start it a tiny puff of blue smoke comes out of the tail pipes.? it never did that with the old engine, and it never smelled like it does now.??



its a 99 grand am gt... 3.4 liter v6 (notorious engine i know, lol). but yea.... someone help me out!!! :-)



and thankxxxx ahead of time !!'99 grand am, new engine..weird driving when engine gets hot?? help?Vacuum'99 grand am, new engine..weird driving when engine gets hot?? help?Well I know that a lot of cars, when the engine is cold, it will try to shift to a higher gear when you first step on the gas, than when the engine is warmed up. The reason for this is the engine is trying to warm up, and this method will assist the engine in doing that. So it could be that the car is just trying to warm up, but if it really concerns you, I would check it out just to make sure that's the case.'99 grand am, new engine..weird driving when engine gets hot?? help?1) Maybe a plugged up catalytic converter would account for the power loss when hot. get the car nice and hot (in your case drive it until it feels sluggish) then connect a vacuum gauge to manifold vacuum...open the throttle about half way and hold it there while observing the gauge. the vacuum reading should drop when you open thr throttle at first but then climb back up and hold a steady reading thereafter.



If the vacuum reading starts to fall and continues to do so as you hold the throttle open then you likely have a plugged up cat.



2) If you have a scan tool you can connect it and scan the car for trouble codes stored in the on board computer.



thats where i'd start....