Temp Gauge Reading

[Seneca_Tiger]

I've noticed a few things on my wife's 2002 Malibu that are a little strange. First, the coolant temp runs consistenly about 1 tick mark over halfway (sometimes a little higher sometimes a little lower - it moves around a little bit). Since the gauge reads from 100 to 260, I estimate that this temp is about 190-200 degrees, which is normal operating temp (I think) but am I right about this? Before I had the lower intake manifold gasket replaced it would idle just below halfway but now it is a little hotter. The mechanic who did the repair (at Oconee Auto Service in Seneca, SC in case anyone here is familiar with the area) told me it was running about there after he did the repair but acted like it was fine. They put in a new thermostat when they did the gasket repair. They also told me the cooling fans don't come on until the coolant temp hits 235 degrees and cut off at around 215.

Also, when the car sits after being shut off and then I turn the key to "on" (I have a habit of stopping the key at the on position for a second before starting it) the temp will show higher than when I shut it off. Once the car starts running the temp comes down pretty quickly, whether it's idling or I go ahead and start driving. Could this be a faulty gauge, a bad sensor or something else?

[Johnny R]

1. "one tic above.." It's a steady reading; that's a good indication that the guage is reliable. I think you're good to go.
2. On my 99 Malibu I notice minor fluctuations, due to driving conditions such as, long idling on very hot days (Don't jump on me, I hardly ever idle while parked).

[johnschmitt]

My 99 does exactly everything you discribed. (so they're both fine or both broken) The stat supposedly opens at 195. Mine will fluctuate from 185 to 200 depending on if the red light's in the sun or the shade.

My gauge climbs when I restart it a few minutes later too. That's just the stationary water soaking up heat from the engine. Not a problem to my knowledge.




..btw, you're not the only one who lets the fuel pump build pressure in the lines before turning it over. I swear my fiance thinks she has to turn the key as fast as she can or it won't start. Opposite usually holds true.

[madmedix]

Mine was steady until her intake gasket went, and post-repair the temp guage bobs a little too. That was over 80K ago. You should be fine.

[Speedy_1234]

Ok But does the fans Work when it reaches the 190 or should I say two lines above the middle. Both fans should come on at the same time. Also Do you use the A.C. if not you have to use it in order the whole system to curculate Also When you turn on the A.C. does the fans go fast or slow one or both.

[Seneca_Tiger]

Originally Posted by Speedy_1234

Ok But does the fans Work when it reaches the 190 or should I say two lines above the middle. Both fans should come on at the same time. Also Do you use the A.C. if not you have to use it in order the whole system to curculate Also When you turn on the A.C. does the fans go fast or slow one or both.

I haven't checked mine. The 235-215 was how it is supposed to work from the factory - I assume mine is working okay since it doesn't overheat at idle. In fact, before the repair it seemed like the fans kind of came on whenever they wanted to, whereas now they seem to be more consistent (though this could be my imagination). I asked if there was a way to make them come on earlier but he told me there isn't, and if you did manage to do it the fuel economy would plummet.

[Speedy_1234]

Ok I remember When Suddenly My Malibu started to cause the radiator cap to pop off. I had barely fix the heads new half motor gasket set and temorstat. But What I did not change was the temp sensor (the one located outside of the housing of the temorstat). See the heads were ok the temorstat was ok but the fans were no kicking when they should the were kicking when the radiator cap pop off(in other word when the car overheated).

[Seneca_Tiger]

Had a '86 camaro with the 2.8L V6 (which is what the 3.1 is based on) do that once. It never overheated (primarily due to luck) but as soon as I would stop the temp gauge would start climbing. Since I was in college I was able to limit my driving and avoid long stops until I could get it fixed. In my case it was the relay. This is one advantage to the old-style fans that mount to the front of the water pump and have a clutch - they really can't fail like this. Of course, putting this type of rig on a transverse engine would present a slight problem.

As an FYI, I had a friend who had this same problem and, since he could not afford to fix it right away and since he was pretty clever, he wired the fan to his headlights, so if the temp started going up all he had to do was flip on his headlights! Could work temporarily in a pinch if you know what you are doing.

[wade623]

i drove my 99 malibu about 100 miles non stop on the freeway at times the temp was 4 marks over half when i was doing bout 85-90 but it usally stays on half or one to two marks above should it go up that high

[Speedy_1234]

If you have the termostat at 190 mostly that what the car comes with
but i think you can fine a lower one at 160. (it means that the when the temp reaches to that degree it open the termostat and lets cold antifrezze in the motor)

[Speedy_1234]

By the way are both fans working when it reaches that temp and plus do the spin slow or fast

[wade623]

it goes from 100 to 260 but it only got that hot when going that fast but the fans do work

[Speedy_1234]

What About codes anycodes com out, or does the service vehicle soon light is on

[wade623]

no the light does not turn on it doesnt stay that high all the time