So the basics - 95 coupe, v6, 145,000 miles, stage 2 heads and intakes. Replace the water pump about 3 months ago, replace the alt about a month ago - now to the problem.

In december I lost a HG and as a result upgraded a few things (intakes, heads, TB) and when I got the car back the normal operating engine temp was around "N" even on a hot day. About 3 weeks ago I noticed that the engine was getting up to "L" and that freaked me out being I had lost the HB once and was afraid I was going to loose it again. Well I was watching the temp gauge very close and notice that the temp will get up to "L" for about 30 seconds then fall back to between "M" and "A" for about 30 seconds then drop down to "N" for about a minute before going back to the "MA" position. It does not matter if Im driving side streets and sit at red lights or if Im doing 65 on the freeway (which makes me think there is something in the coolent lines like a air bubble or something) it keeps doing the same thing. The straingest part is sometimes the temp will shoot up to "AL" within minutes of starting the car, and other times it will take 20 minutes of running the car before it gets that high.

Any ideas?

Thanks,
Matthew

 

Temp sensor malfunction?

 

Fink I was thinking the same thing, but for the sake of argument that Ive already replaced the tempt senson. What would be the next thing?

Thanks,
Matthew

 

idk but mine does something similar. gets hot outa nowhere. i blast the hot air for a bit, turn engine off for a while and when i run it again its fine...

 

Loose connection to the sender?

 

I did that the first time and dont want to have to do it everytime the car warms up.I cant pull over and wait a 1/2 hour when Im on my way to work.

Which sender? The temp sender?

Matthew

 

You have two sensors Matt. One controls the PCM(closer to passenger side, and the other sensor near the tstat housing controls the gauge. I would bleed the system when it's cooled off. There's a bleeder screw on the top of the tstat housing. When you changed the water pump, did you change the tstat? It very well could be a faulty sensor, but IMO, probably not the case.

 

Update. I did check the coolent temp sensor on top of the tstat and it was in place, no wiggle or fraid wires. No I did not change the tstat when I changed the water pump. My feeling is that its not a bad sensor but something going on with the cooling system.

More info - turning the heater on FULL BLAST does NOTHING to bring down the engine temp. It stays close to "AL" on "Normal". I did notice that I did not get hot air blowing thru the vents with the heater turned to full blast when I was at a stop (red light, or stop sign). I would only get heat when I was moving.

Thanks,
Matthew

 

bummpy

 

Honestly check over the drivebelt, check the radiator & heater core for obstructions / abnormal bends, if you find nothing id just flush the **** outta the system put new coolant and burp it out just to be safe.

Maybe your radiator cap is just intermittently releasing pressure and showing signs of age? replace it? Could be an air pocket idk...

other than that stuff it's the obvious stuff like checking coolant levels and seeing if the thermostat is stuck. Or perhaps the harder electrical stuff....Good luck.

If that fails id definatly bring the car to a reputable shop and run a gas analyzer over the radiator just to make sure another head gasket didn't blow.