86' 944 runs hot
 

Hi guys,

I own a 1986 944 na, i had the water pump, all the belts changed and the thermostat, head shaved and new gaskets, new valves and guides. Runs good but run very warm. I flushed the system yesterday and put 2 gallons of new antifreeze in it. I will run in the middle on the highway but on the streets, it will run on the third white line up to the bottom of the red line. If i give it some gas the temp will lower somewhat. I made sure there was no air using the bleeder. Anything i should be looking for?

RE: 86' 944 runs hot
 

Bleed it again. As you heat up the cooloant, more air comes out of solution.

RE: 86' 944 runs hot
 

Thanks, i will try that tomorrow and let you know how I made out.

RE: 86' 944 runs hot
 

When i bleed it, i basically keep the bleeding valve open until the coolant comes out with no air gaps, then i close it, is that pretty much it?

RE: 86' 944 runs hot
 

Ayuh......

RE: 86' 944 runs hot
 

how much air should be in the system, i bled it when it was hot and the engine not running then when running. Seems to be air in the system still. Whats the best way to bleed the system? Still runs on the line before the red, sometimes it will run in the middle of the gauge when on the highway. Fans are running when its getting warm. Any suggestions?

RE: 86' 944 runs hot
 

Bleed it til you get all the air out.

RE: 86' 944 runs hot
 

I bled over a 1/2 gallon of antifreeze out of it, still sputtered a little. What is the best/correct way to bleed it? Running, not runing, hot, cold, etc?

RE: 86' 944 runs hot
 

Bleed vent at ambient temperature. Raise the front wheels on a ramp or similar, then bleed the air.

RE: 86 944 runs hot
 

Hi,

I bled it again, still ran hot. I "cleaned" the radiator on the outside, figured it couldnt hurt to rinse with some water, just in case it was dirty.The temps seem to be slowly getting worse, not its running between the 3rd line and the red line on the highway and the funny part is that its much cooler out, temps outside in the mid 50's. Any more suggestions, I am getting concerned since its my wifes daily driver.

Thanks

Eddie

RE: 86 944 runs hot
 

put in a new thermostat just in case the old one was no good and now its worse, runs almost at the red line. Bled it out again, one gallon this time and still running hot. I NEED HELP!!!! :)

RE: 86 944 runs hot
 

Ok, i decided to bleed it one more time, temps are now at the red line. I figured for the heck of it i would see what temps i get with my temp gun, (i am big into RC stuff) and I am getting 220 at the bleeder housing, 175 on the upper hose, 190-198 on the engine itself at the base of the valve cover, when you open the hood it doesnt seem very hot at all. Is it possible the sending unit is not working correctly? It reads at the bottom of the line when you first start it but quickly climbs to the 3rd-red line (within 10 minutes) and its in the 50's here. Where would I find this sending unit on the engine?

RE: 86 944 runs hot
 

Does anyone know where the temprature sending unit is on a 1986 porsche 944, not the one for the fan but the one thats for the temp guage, i cant find this anywhere, even the repair manual i have. Even though its at the red line i take the temps with a temp gun i have and it reads around 220 at the bleeder housing, 190 at the head, 180 at the upper radiator hose.

RE: 86 944 runs hot
 

Hey, another thing you should look at is on the reservoir by the cap is a rubber hose, that is your pressure release hose. Make sure that that hose isn't bent or stopped up. I just had the problems that you're having with my car and fixing that tube solved my problem.

RE: 86 944 runs hot
 

Thanks for the reply, i just checked all the hoses coming from the reservior and they all seem fine, its very strange. I honeslty dont think its overheating unless a 210 degree engine is overheating, thats the temp i am getting on the engine itself with a temp gun. I would think that the needle on the red that it would be warmer than that, the engine doesnt seem to be hot, you can usually smell or feel the heat from a hot engine.

For the life of me, i cant find the temprature sending unit, lol

RE: 86 944 runs hot
 

ok, the bottom radiator hose is ice cold, top is hot. I am going to remove the thermostat tomorrow and see what the deal is, i have put 2 new ones in but what else could it be, i will run without the thermostat and see what the deal is.

RE: 86 944 runs hot
 

that's normal. if you look back in this forum you'll know why.

RE: 86 944 runs hot
 

could you enlighten me? I have searched these and other forums with no answer. Why not just give the answer? I dont think an engine overheating orsaying its overheating is normal.

RE: 86 944 runs hot
 

sorry bout that, i was wrong.

RE: 86 944 runs hot
 

ok, put another thermostat in it, this one has a small opening on it, was told this is the correct one, its 180 not 195 like the one i just put it, runs in the middle now or goes to the 3rd line. Bleeding the air out of it and seems like its getting better, the serpantine belt flew off so i had to have it towed and replaced today and the mechanic took the the thermostat out to check for me and thinks thats the problem, i will let you guys know.

RE: 86 944 runs hot
 

Suggest you also check the thermo switch. This turns the radiator fan on at a pre set temperature depending on what part number thermo switch you have. I would replace the current one with the lowest temp one you can find.

RE: 86 944 runs hot
 

Thanks, i will check that out also, it seems to come on when it gets close to the third line.

I ran the car last night and today, runs at or right below the 3rd line, much better than before when it was at the bottom and above the red line. Will bleed it more and see since there was some air in it last night.

RE: 86 944 runs hot
 

Not to be to simplistic, but did you replace the radiator cap?

RE: 86 944 runs hot
 

cap is fine, tested it. Today its fine, run above the 1st line slightly on the highway, gets to the 3rd line on the streets and you feel the fans come on and the temp drops. Must have been that termostat.

Only problem is the cooling system is not holding pressure. Will drop from 14lbs to 0 in about 5 minutes. Nothing is leaking on the outside (hoses, etc.), the oil looks fine, not foamy or tanish looking. Hope the head/gasket it ok, i just had it machined and new gasket. I will keep my eye on it and see [:o]

RE: 86 944 runs hot
 

There may be an issue with your water pump pully, check out http://www.clarks-garage.com/
There is a procedure in the garage shop manual to check this -[align=center]TS-02, Troubleshooting - Cooling System[/align][align=left]Is the lower rad hose warm now when the thermostat is open?[/align]

RE: 86 944 runs hot
 

Hi,

It seems all is better now, i think it was the thermostat, it runs a little above the 1st line, when sitting it traffic it goes to the 3rd, fans kick on and the temp drops back down. Funny how 2 thermostats were no good, the one we put in this last time was a german one with a small bleed type hole in it, looked different than the other one too. I will check the link you gave and see what i can find out. Still a little concerned about the system not holding pressure, unless his pressure tester was not good because i let it sit for a few minutes when i got homeand checked for air and there was pressure and no air and no fluid is missing.

Thanks for your replies

RE: 86 944 runs hot
 

First of all,what temp thermostat did you replace the old one with?

RE: 86 944 runs hot
 

the original was replaced from a shopso i dont know, the second one that i had put in was a stant 195 degree, that made it worse, the one that was put in now is 180degrees with a bleeder hole in it and its been running fine.

RE: 86 944 runs hot
 

Also I have know racers that use a turkey baster to force coolant into the bleeder hole to get all the air out of the system.

RE: 86 944 runs hot
 

Thanks for the suggestion, so far so good, it must have been that thermostat, newest problem was the altinator. Changed and all good!!!!

Now i just need to figure out the oilpressure gauge and charging gauge are always pinned to the top, unless the key is off. Most likely the plug on the cluster, will take out over the weekend or something.

RE: 86 944 runs hot