Questions and Answers

Chevy S10 Engine Temperature Q. I have a 1997 Chevy S10, 2.2 liter 4 cylinder, power steering, ABS, cruise, no A/C, automatic transmission, 90,000 miles. My tmperature fluctuates from about 160° to 195°, even when it is warmed up to full operating temperature. I look down one minute and it might read 170°, the next time I look, it might read 190°.

What is the deal with this variation in temperature? We also have a 1998 Blazer 4.3 liter, it reads a steady 200° once its warmed up. Also, my #2 and #3 cylinder spark plug holes seem to get wet with something. I was looking at it and noticed a fluid residue all around the plug. I got a sample of the fluid and it has no distinct smell, so I'm at a loss as to what it is.

Thank you very much for your help!

A. Those 4 cylinders are prone for leaking cylinder head gaskets. They leak outside the engine at the rear of head. If the system has air inside, this would explain your temp fluctuation. A pressure test of the system would be my first priority. Then replace the thermostat and make sure the radiator is not plugged inside or air is blocked from going through it.