hashiru

Ok...I have been through the numerous prior posts on this topic, but as a mechanically challenged owner I am looking for some advice...

I have a 1990 S2 Cab...The car usually runs just above the lower temp line, until two weeks ago. Since then the car seems to warm and run normally until I come to a stop (light, traffic, whatever). The temp then rapidly but steadily climbs to the upper white temp mark. Generally the temp comes right down as soon as the car starts moving. However, in the last few days that does not always occur. At times, becoming more frequent, the temp will remain at the upper white mark until the hearter is turned on. The temp then comes back to its "normal" position at just above the lower white line.

The 1st fan is on and I can hear the second kick on at the upper white mark, even when the temp does not come down. On only one occassion has the temp inched above the upper white line and that came down when the heater was turned on.

Now for the nut in this batter....last night I am driving along and all is as above, normal at first, climing to the upper white line at a stop and coming down when the car is moving. Toward the end of the drive the car is staying at or near the upper white line even while driving in cool air. I turn on the heater and feel cool air from the vents for about 30 secs followed by hot air for 15 sec and back to cool air...the temp stays at the upper line.
The other quirk was a "bouncing" of the temp guage...just last night and only twice, from the upper line to mid point and back.

I am planning on flushing the cooling system this weekend. Thoughts? Tstat? Someting else? The car runs fine and has no other problems...

Help......

Yabo

check grounds, or else you n eed to flush.

although, mine is flushed, and it stays at the 1st line until stopped at a litght for over 30 seconds or so, it goes up to the highest white line (not the red) and then there the second fan turns on and brings it right back down to at least half, until im driving again.

bearone

small leak over time, have you checked the water level?

Scooter

I had a very similar situation a few weeks ago. My car would consistently rise to the top white mark and sit there. If I got stuck in traffic, it would inch higher. Once I got moving, it would come down a bit. It got worse the hotter it got here in Toronto. I tried to bleed the system but the coolant tank level never dropped while I was trying, making me suspect the T-stat. the shop confirmed it was a new T-stat I needed, now I'm back to normal. I also added an additional engine ground and that stopped the needle from twitching when I raised or lowered the power windows. The needle also bounced a touch but not that much before.

Bhj0887

I never had this problem in the 944, but in my old beater Spirit this happened and now the new beater Spirit I got for 500 bucks. If flushing the system doesn't correct your problem, you water pump is probably on it's way out. If it is indeed your water pump, your looking at about 500 labor alone then an extra $300 or so for the pump, plus you might as well replace the timing belt (it's comming off anyway) while your in there as well as all the other things (seals, rollers etc.).

God luck. Hope it's one of those cheap fixes.

hashiru

Thanks...I don't think there is a leak. I will take on the dreaded, but thankfully cheap, Tstat change this weekend along with the coolant change just to be safe...

Chris_924s

sounds like one of 2 things-
#1 bubble in the coolant system .
Normally my fans kick on as I approach the 3rd line- and I know my coolant system is fine- no air.

#2 check the grounds in the headlight buckets. clean 'em off and see if the problem goes away.

I love problems that require ZERO dollars..

and Welcome to Rennlist!

led

And I thought it was just me having temp problems... It's that time of the year again!

pete944

Have the radiator cap pressure tested. If it doesn't hold pressure it can cause overheating.
If you have to replace it, don't buy a cheapo at the local parts store. Get a good quality Behr cap. I had this problem on my 85.5 and it was a cheap cap.

theedge

I had those symptoms when my waterpump was near locking up, then it started to leak.

Now, 2 weeks later, its doing it again

Anyway, try revving to around 2k rpm when it heats up like that, just sit there not moving and hold it at 2k or so. Any change?

hashiru

Just an update...flushed the system....re-filled...long drive...no temp problem....Hopefully it stays this way. A lot of "gunk" came out....Thanks for all the help..

Mongo

just where exactly are the headlight grounds you are talking about that connect to the radiator fans?

Andy