96 Taurus 3.0L driveability problem...

Hello,

Taurus runs fine normally, no codes. Sometimes temp guage is going all over the place, in traffic, at lights, uphill etc. Seems to be getting hot. Coolant levels good. Then it will run fine on the highway. I notice uphill or if I mash the gas, it seems to want to bog itself way down as if it's being smothered and if I let off the gas and ease it up to speed, it will run fine. I'm thinking maybe coil or ignition module, along those lines, but wouldn't I be getting a code, if it were those?

Thanks.

If you are experiencing a misfire, it may or may not set a Check Engine Light (CEL). There is a threshhold for setting a misfire code P0300-P0310. Your engine can be misfiring enough that the component parameters will show it on a professional scan tool, but not enough to trigger a code. When I still had my 1998 Taurus SHO, I had 3 coils go bad enough that I could feel the misfire while driving, but not a single one of them set a code.

When is the last time you had the car tuned up with a new air filter, fuel filter, spark plugs, spark plug wires, fuel injector cleaner added to the fuel tank, and possibly even the MAF cleaned?

-Rod

Thanks for the reply Rod. I keep the car tuned regularly. It's Mom's car so must be. I've experience coil problems on other vehicles, but thought it would give me a code. It's just this one is dogging me for awhile, with no obvious culprit. The temp guage rising up/down is my main concern though. I'm gonna try a few things and I'll let you know if they worked.

Regards,
Mike

The fluctuating coolant temperature guage could indicate an air pocket in the cooling system, a faulty coolant temperature sender, or an issue with the instrument cluster. You may want to consider plugging in a scan tool with a datastream capability if you have access to one and compare the readings for the coolant temperature against what the gauge would imply.

Your Taurus uses a coolant temperature sender for the gauge and a coolant temperature sensor for the PCM. If the temperature as reported by the scan tool does not fluctuate, then you should consider replacing the sender. If that doesn't fix it, then you are probably looking at an issue at the instrument cluster. Some Taurus owners have reported issues with the flex circuit on the instrument panel.

-Rod

Thanks Rod. I'll look into that.