Hi guys,

I have an '86 944 NA and I have noticed the coolant temps going up and down when driving around.

The temperature gauge is all over the place--it spends most of its time in the middle, but it can vary up and down to the 1/3 marks (both ways) depending on whether the car is sitting or whether I am driving hard, etc. However, I cannot find a direct relationship between the hardness of my driving and the coolant temps.

Is this completely normal? The previous owner told me this is normal and that I may just not be used to it because newer cars have idiot gauges.

 

On an 86 your temps while cruising on the highway should be dead stable at or slightly above the first mark. In heavy stop and go traffic the temp will usually go between the first to 3rd mark even if your cooling fans are operating right. Running the AC in traffic will usually push it between the 2nd and 3rd mark with the high speed fan kicking in when it hits the 3rd mark. If yours is bouncing all the time, no matter what driving, then you might either have a poor gauge ground, a loose sensor wire, or both your fans aren't coming on correctly. This is how most late cars I've owned react; yours may be different. The early cars bounced all over the place having only a single fan. Many people worry their car is overheating but it really needs to hit the red area for that from my experience.

 

When the fans cycle on, they stay on long enough for the temp to drop. What you describe sounds like more than that, tho.

 

Pretty much how it is. Takes a bit getting used to.

 

example- on the track my car stays horizontal completely the entire time- pulling off the track the temp will rise to the next line, then the fans kick on, then it goes back to horizontal. Sounds like you have an air pocket.

 

is the voltmeter moving too?

87951
95sl320 dd

 

If your gauge is just moving slowly and as you describe, you're probably fine.

What most people aren't used to is that these are real gauges. Get into a new Ford, Honda, etc, and they are "idiot gauges". The don't move all that much unless something is really wrong (they are usually heavily dampened like a fuel gauge).

 

The 944 gauge actually moves with temperature. So as the engine temp moves so does the gauge. Most modern cars have gauges so damped that they never move. This give the driver a warm fuzzy.

So as temps change the gauge will move between the white lines mostly. If it going outside those lines or moving very rapidly you have an issue.

 

I agree with other answers, but if you live in a moderate climate and regulalry see the temp swing all the way between the two white marks (i.e., the marks at 8 and 10 o'clock), then I would check the system before concluding it is ok. In ambient temps under 90 or so, I rarely see the gauge get above half way when all is working as designed -- occassionally yes, but not a normal part of the cycle -- with a stock thermostat too. If nothing else, I'd make sure you confirm the fans are coming on by the time the gauge gets over the first (8 o'clock) white hash mark. And that the fans run when the a/c is on. And that they kick into high speed mode as you approach the upper white hash mark. Also be sure that the system is fully vented, with no trapped air. If you hear gurgling when you turn on the heater for example, you have trapped air. If the temp climbs fast at idle, and drops very fast when you rev, then you likely have trapped air. If you find yourself venting over and over and over, you may have a leak letting coolant out and air in. Pressure testing will find external leaks. Also, the radiator can get old and inefficient, especially if dirty on the outside or blocked with debris. Also, sometimes people will use the wrong thermostat or thermofan switch (or mis-match them) which can make the car run hotter than normal or cause the temp to swing more than normal. Might want to check next time "you're in there" or sooner if obsessive.

 

...which seems to be a common failure, as the low speed resistor pack (or at least the wiring to it) fry. Easy check, and good for avoiding fires.

 

I looked at it more carefully on my drive today. It seems to go a little higher when I am stopped or driving in town, but when I'm driving at a speed above 35 or so (even if I'm driving hard) it seems to stay right in the middle.

Thanks for all of the replies!

 

lol. my moms van (2006 honda odyssey) does not move either. that stays in the middle all day long. nd everytime i go to nyc, during stop nd go traffic, i look at it, and its nice to know its not overheating. IE that warm fuzzy feeling