1994 Olds Cutlass Supreme problem

[Raydee]

My Cutlass(3100 SFI) is having problems once it shifts into Overdrive. It seems like it is studdering under the load. It will also do it after it is hot and I am going up hills or loading the engine up. It almost seems like a miss or something. Could the coil packs be bad? I was told not to get aftermarket ones and that the OEM are the best. Anybody have any experience with this?

[mrcutssupreme]

Originally Posted by Raydee

My Cutlass(3100 SFI) is having problems once it shifts into Overdrive. It seems like it is studdering under the load. It will also do it after it is hot and I am going up hills or loading the engine up. It almost seems like a miss or something. Could the coil packs be bad? I was told not to get aftermarket ones and that the OEM are the best. Anybody have any experience with this?

Don't worry I have the same exact car and that same exact problem. Are you talking about once it's in overdrive and you accelerate just enough to where it stays in overdrive and doens't drop a gear, the whole car shakes? if so, get your manifold cleaned out. We took it to the dealer and there was an unbeleivable amount of carbon build up, sure it cost about $300, but man was it worth it, she purrs nice and smooth in overdrive. Good luck!

[Slade901]

Originally Posted by mrcutssupreme

We took it to the dealer and there was an unbeleivable amount of carbon build up, sure it cost about $300, but man was it worth it, she purrs nice and smooth in overdrive. Good luck!

$300 ?
That's a lot for me.
You can get yourself the GM Top End Cleaner for about $5 (usually available at GM Dealerships) or get SEAFOAM Motor Tune Up for about $5 (usually available at NAPA).

I would however replace the PCV valve if it has not been changed for a long time. You can search the web and type "PCV Catch Can". It is designed to trap the oil from the air/oil vapor before going into the intake. Oil lowers the Fuel Octane Level and causes knock. The breather hose side of the PCV system is suppose to suck air in but pressurein the engine causes air/oil to come out instead of the breather hose and introduce it to the intake (lowering the fuel octane level). Oil in the intake causes carbon build up and gunk in the intake manifold and clogged up sensors.

[Slade901]

Originally Posted by Raydee

My Cutlass(3100 SFI) is having problems once it shifts into Overdrive. It seems like it is studdering under the load. It will also do it after it is hot and I am going up hills or loading the engine up. It almost seems like a miss or something. Could the coil packs be bad? I was told not to get aftermarket ones and that the OEM are the best. Anybody have any experience with this?

Just make sure you that the spark plug wires are separated from each other with a spark plug wire separator. Make sure that each spark plug wires are not rubbing the engine block and use some tie wrap to move the spark plug wires away from the engine block.

[Viper99991]

My car is doing the same thing i replaced the egr valve and it was fine for a week then it did it again now i know what it is you guys helped alot deep up the good work