2001 Chevy Impala Engine Surge Diagnosis - Vince Ciulla
This weekly Q&A session answers your questions about cars and trucks. This week explores a who has an engine that surges.
- I have a 2001 Chevy Impala with a 3.8-liter engine. I have been having problems with it surging and dying while driving down the road. I put new spark plugs, plug wires, and fuel filter in this summer. The car started surging probably about three to four months ago. About three weeks ago it started to die while driving it down the road and then didn't want to start. So, I replaced the fuel pump, and the fuel filter, and it continues to surge. What else could be causing the problem and what else can I do to try to fix the problem.
- Many things, both electrical and mechanical, can cause surging in an engine. One of the main causes is a bad Engine Coolant Temperature (ECT) sensor. If the ECT is malfunctioning it will give wrong information to the Powertrain Control Module (PCM) and the PCM will not be able to meter the proper amount of fuel the engine needs to operate efficiently.
- The best way to test this is to let the vehicle sit overnight and in the morning connect a scan tool to the diagnostic connector. See what the temperature the ECT is recording. It should be within two to four degrees of the ambient air temperature. If not the Engine Coolant Temperature (ECT) sensor is bad and needs to be replaced. Very often the ECT will not turn the Check Engine Light on since, electrically, it is still working. However mechanically it is malfunctioning.
- Another reason an engine will surge is because of a bad Torque Converter Clutch (TCC) solenoid. A bad TCC will also cause the engine to stall under certain conditions. If a vehicle goes over 45 to 50 mph and then comes to a stop and stalls, that's a good indication the TCC is bad.,
- Another more common cause has to do with engine basics like spark plugs, ignition wires and ignition timing. A partially clogged fuel filter or clogged air filter can also cause a surge. So it is usually a good idea to Check The Basics before looking for a more involved problem. Many times a problem has a simple cause and solution.
That's all for this week. Feel free to browse the archives for past topics and other resources. And, as always, if you are stuck and need an immediate answer you can always call Vince on the phone. For a limited time new callers get the first three minutes free!
Copyright Vincent Ciulla. Contact the author to obtain permission for republication.
Vincent Ciulla - Vincent Ciulla has been a professional automotive technician for over 35 years and is a certified master technician with experience in ...
