[pnbell]

I drive from Baltimore to DC everyday and the temp has been 80-90f degrees outside lately.
In traffic my temp gauge -fluctuates a bit- but usually gets up, and stays a little above the second bar. (Late 944 gauge: above middle) According to Clark's garage over 212f...
Inaddition, this high temp causes my oil pressure to sit at 2 bars (.5 less than normal) and my engine seems to run slightly rougher.

Happens with AC on or off. Fans are running. Have bleed the air from the coolant.
I was thinking of installing 160 degree thermostat and lower fan switch.
Any thoughts? Anyone running lower thermostat? Issues?

[jerome951]

Sounds perfectly normal.

The lower temp thermostat won't help. It will open earlier but the steady-state temps when driving in traffic on hot days are well above when it opens.

The lower fan switch would help. Alternatively, you can wire a switch to manually turn on/off the fans while retaining full function of the factory operation (I've done this for my track car).

How many miles on the radiator? Those tend to get crudded up over time, both internally and externally. I saw a temp decrease when I replaced mine.

[racer]

If the coolant is "new", and has no air, and the fans are working, I would say that this is good.

As for oil, what oil are you currently running?

You also don't mention if the car has always behaved this way or if this is new.

Does the car spike while sitting in traffic? Does it cool off once you get more airflow over the radiator?

I only got my 944 last fall, so it hasn't seen many hot days, but yes, sitting in traffic, on 80+ degree days, i recall my watertemp sitting at the middle of the gauge and wasn't suprised by it.

I also changed out the 10w-40 that was in there with some 20w-50 (or was it 15w-50) as I feel it copes better in hot summer weather.

[pnbell]

I am running Mobil1 20w50. I have not seen temps this high, accept over the last few weeks. However i just purchased the car back in September, so i have never really seen hot weather with it...

A couple months ago while parked the coolant boiled over; it was due to a disintegrated Rad cap seal. Replaced.

Radiator could be original to my knowledge. Just wanted to get feedback because the next line is the danger zone!

Additional feedback is of course welcome -for both me and future forum searchers)

(As for wiring a manual fan switch) I am interested in doing this. Any tips?
I assume you could splice a line in the positive fan thermoswitch wire and run this to a manual switch with ground. Correct? Need for a fuse?

Thanks for the quick replies!

[Redroc]

Have you checked the coolant concentration? Coolant runs hotter than water. If your concentration is too high the car will run hotter. 50% coolant is what all the manufacturers recommend but if you look at the freeze temperature its something like -30°F. You can run a bit less concentration around here. I typically run just distilled water & water wetter in the summer. The car didn't even get hot at the track with that combo.

Porsche now recommends 0w40 for most of the 944 series (if not all). I used Brad Penn 20w50 for last year's track season. The car was running hotter than the previous track year's Redline 5w40 that I was using. I've got Mobil 1 10w40 in the car right now. We'll see how it does this weekend at Shenandoah Circuit. It's supposed to be a warm weekend.

[Lupin..the..3rd]

Originally Posted by pnbell

Radiator could be original to my knowledge. Just wanted to get feedback because the next line is the danger zone!

Revvin' up your engine
Listen to her howlin' roar
Metal under tension
Beggin' you to touch and go

Highway to the Danger Zone
Ride into the Danger Zone

[smo]

I don't have a "next line" for the danger zone, it's just marked off with an orange line on top that drops down denoting an area at the top of the gauge. Anyway, that sounds pretty normal on hot days. I've seen mine get above it a few times but the fans kick on when it gets pretty close to the bottom of the top most line.

It could also just be a simple grounding issue and you are just noticing the temperature now that it is hot outside. I've noticed in my car that prior to repairing my odo gear that the gauge would read near the second line frequently in warmer weather. Since I've put the cluster back in and reseated things I haven't seen it do this. We are just getting into the warmer weather though.

Additionally I've noticed that the gauge flicks around sometimes with the turn signal blink frequency. If the a/c is on the gauge reads higher. When I have the lights on the gauge moves up. When I stand on the brake the gauge moves up. At night at a dead stop with my turn signal on you'd think the engine was going to blow.

So I guess my point is. Check out the grounding around your cluster before worrying about the harder stuff. Also, if it drops almost immediately when you start moving again then that is normal AFAIK.

[pnbell]

OK. This is all good stuff to hear. -and no there is no Danger Zone line... just an area with orange at the top-
My gauge does electronic related things also; like clicking up a little when turn lights on...
My odo gear fail pretty recently so when I replace it I will check and clean the grounds. And replace my dim ass dash lights...

[RedOctober]

My '86 sits between the center line and the next line up (and there is one more line after that leading to red).

As of last month, I am running all distilled water with one bottle of WW and it does seem to run cooler now. The highest it gets sitting in traffic is just below the line above the middle. At Shenandoah a couple weeks ago, that was the highest it got as well.

Mine will start to go down as soon as I start moving as well. At the track, nice fresh air on the straights made it go down as well (of course I had nice clean air since I was not on anyone's rear bumper )

[pnbell]

I was thinking of adding WW to my coolant? Though I hear mist people running g only We and distilled. Any thoughts on just adding to 50/50 coolant?