ztnedman1

Okay. IT started early this morning with radiator fluid starting to leak. During driving during the day my heat kept getting really high. By the end of the day I was very worried since the car is leaking radiator fluid like none other. it just doesnt stop leaking, its not even drips anymore its strait stream! Things I found were that if i reved up the engine the temp would drop from high line down to just below the bottom one. After 4 hours of this the car just wouldnt drop at all. I read an earlier post about grounds? When i turn on my lights the temp jumped up a little. Also my oil pump gauge is buried at the top of its range. So when i was driving home my car slowly kreeps up towards the red and once it got close I pulled the car over and turned the engine off. When i went to open the hood, the hood felt cold. There was no heat at all. I opened the hood and all was normal. The engine seems normaly heated. my fans work as usually and run for about 30 secs most of the time after i turn my car off. But i found it very strange that everythng was so cold. The hood, everything was not even warm to the touch, and I KNOW that an overheating engine would be hot as hell. So whats going on here? Is it really electrical and could the oil pump being buried be caused by a similar electrical prob? I stopped believing my cars temp since it wasnt hot but i dont get why its leaking SO MUCH radiator fluid. Is this a simple fix? And what would i need to do to fix it myself? Or should I take it to my mechanic?

P.S When I turned full heat on all I got was cold air.
P.S.S My car is an 86' 951

hosrom_951

Where was it leaking first of all? Leaking like a stream? too much pressure in your system

But in your case, i syspect an electical AND thermostat problem. You oil pressur egauge it pegged high means the sender is bad.

Try replacing the cap to see if it would continue to leak or not. If it does, you should find the source for leaks. But since the temp goes up and everything is at normal running temps, the thermostate for the turbocharger should also be checked.

Charlotte944

Either the engine thermostat is blocked closed, or the radiator is blocked.

ztnedman1

Im thinking that its the gronds since when i revved the car up the heat gauge started workign again. Also when i drove the car to put it in storage the heat gauge worked for a good 30 mins before it all of a sudden messed up again. I filled up the radiator fluid again when i put it in storage and over about 2 days it all leaked out again for the most part. (found out some was in the water pump).

Anyone know where all the ground are for the cooling system on this car so i can cheak them???

I want to check them before taking the thermometer out of the water pump since the snap ring holding the themometer in and location of the water pump seems like a REAL PINA to take out and put back in.

ztnedman1

someone surely must know?! I tired looking at my haynes manual to find them but........ what little i did know on how electiracal diagrams/drawings are made i have forgotten. Not to mention they were confusing as hell.

ztnedman1

anyone? anyone know?!?!

jerome951

I've found the main grounds contributing to a flaky temp gauge are the main grounds at the back of the engine (on the clutch bellhousing) and under the dash (lay on your back in the footwell and look next to the cruise control brain; should see 2 brown wires there).

Of course, as mentioned, you may have other issues...

ztnedman1

thank you

Bill

Water boils at 212 degrees farenheit. When water is pressurized, the boiling point is raised 3 degrees for every 1psi of pressure increase. The 944 cooling system is designed to operate at 7psi, thus raising the boiling point to 233 degrees.

So if you have a coolant leak, your system will not pressurize, causing the coolant to boil sooner. The thermostat will not allow coolant to circulate until the coolant has reached a minimum of 190 degrees. Normal engine operating temperatures are in the 190 to 200 degree range. Very close to the boiling point. So you can see how important it is that your cooling system can hold the 7 pounds of pressure.

If you have water leaking, you have a failure somewhere. A bad radiator, water pump, water hose, head gasket, loose bolt, cracked block, etc. You will need to locate the leak and fix the culprit.

Also, a temperature sensor needs to be in contact with coolant (not steam, not air) to detect its temperature. No coolant (read: leak), your gauge will not provide an accurate reading. No coolant, the fan sensor will not turn on the electric fans. Possibly by reving the engine, your water pump is able to send just enough coolant to the temp sender to get a reading and that is why you are getting fluctuating readings. Same applies for the heater. It needs coolant circulating through it to exchange heat. No coolant, no heat will be provided to the cab. This will hold true, even if your engine is glowing cherry red!

You must have really accurately calibrated hands. I for one would not risk melting an engine from using a hand temperature sensor.

ztnedman1

It wasnt my hands. But when i checked it this way my warning light kept flikering on due to overheating. I pulled the car over, opened the hood... there was no heat coming off of it. If it was truly overheating I would have been able to feel alot of heat coming off of it. IT was at night when i checked it so it was fairly cool outside ~75F, So any kind of exteam heat would be easily detectable by human senses.

As for the revving it worked for about and hour gradually not working as much till it stopped affecting it completly.

The fans still worked, turbo timer still worked.

When a car over heats doesnt it flush some of the coolant out of the engine? Thats what i thought the car was doing.

Plus i know the system was pressurized cause the next day i drove around then after letting it sit for around an hours to cool a little i slowly loosened the fillers cap and it definatly was pressurized. I saw the tank go from looking empty to full and air was wooshing out.

Bottom line everything in the car was working properly for the cooling system but it seemed that since the car thought it was over heating it was flushing the coolant when it wasnt over heating at all.

When i drove the car to storage, same thing. After the 30 mins of working right it all of a suddened reported the engine getting critically hot, when it was not over heating.

tconn

If the car is loosing coolant and the warning lights come on then you have a
cooling problem. Don't assume the gauges and warning lights are bad.
If the coolant tank is near empty then you are leaking it some where.
The car does not flush coolant because it thinks it's overheating, it will boil over because IT IS overheating.
If you have a leak you should find and fix it. If there is no leak but it overheats then consider replacing the water pump.

Luis de Prat

Car should not leak even when overheating.

Overheating can be due to a number of things, but replacing the thermostat can't hurt.

When doing this, go over all the coolant hoses and fittings checking for leaks. Hopefully, it's something minor.

Worst case, you're looking at a new waterpump, as was said.

ztnedman1

Im not assuming the gauges are bad. I just think the grounds are shot and they are reporting wrongly. But as i see it looks like i need to take the themometer out and check it.... UGH... hopefully its not the PINA that it looks like.

Luis de Prat

You're going to need a strong set of straight angle pliers. Do a search on thermostat "snap ring" removal, and you'll pin down the best way to get it done.

Worst part is the coolant mess, but if you have a place to work, using some catch pans ought to take care of the mess for you. Good luck.

tazman

[QUOTE=ztnedman1
When a car over heats doesnt it flush some of the coolant out of the engine? Thats what i thought the car was doing.

Bottom line everything in the car was working properly for the cooling system but it seemed that since the car thought it was over heating it was flushing the coolant when it wasnt over heating at all.
[/QUOTE]

The car does not flush the system, the way it works is when the car overheats the coolant system becomes over pressurized and causes the system to release pressure through the cap

Like the others have said you have another problem and my guess would be water pump or thermostat. The reason why the revving of the engine stopped working is because you probably do not have enough coolant to circulate anymore.