Blown head gasket symptoms

Just curious on different symptoms of a blow head gasket…
1. Oil in water – may be oil cooler or head gasket (milk shake)
2. Water in oil – more apt to be a head gasket
3. Low compression in a specific cylinder or two
4. Continuous leak down test pressure loss
5. Continued high water temp at sender and fan switch???????
new pump, new thermostat, new gauge, changed senders (both), bled air, new radiator.

Have any idea why I would have #5 after all the work. Head gasket failure?????

 

You can also experience over pressurization of the cooling system. This can result in blown coolant hoses or even an exploded radiator. A good test is to look at your spark plugs, if your gasket is leaking one of your plugs should look a lot different then the other 3. Are you experiencing white smoke out the exhaust and a rough running engine?

 

NO smoke, engine seems to running fine I just continue to have a high temp gauge and continued fan run on. Not sure what else would give me these symptoms after replacing so much. Any ideas?

 

Perhaps a bad water pump. If it's not circulating the fluid it won't cool. Usually they start leaking when they go bad. Any drips from the front of the engine or excessive noise. When was the last time you replaced belts and or the water pump.

 

I bought a cheap 944 for my daughter and I can't get the temp gauge to drop. I replaced the pump, thermostat, radiator, hoses, all the block seals including the rear main, clutch, rear balace shaft O rings, transaxle, and anything else that holds or contains oil or water.......... Even went as far to change the gauge in the cluster and change temp senders. The temp goes to the second line and stays there with the fans running......does not get any hotter but the fans continue to run. I'm ready to blow it up and put in a nother engine but I know it's got to be something I can fix.

 

Jim,

I know that can be infuriating. It really shouldn't be doing that. I just replaced a head gasket in my race car. The symptom was #2, water in the oil. The wierd thing was that when I tore it down, the gasket was not blown. It was losing water the last 2 races, and the oil was getting fuller. Oil looked terrible, but the water looked good, so I know it must have been slipping around the gasket, but I could not really find anything wrong. I put a new head gasket, and it seems to have solved the problem. My car never did get hot, but it has a 944 turbo radiator in it, so it never gets hot, even on 100 degree days.

Have you checked to see if the radiator is clogged, unlikely because they are plastic, but I guess it is a possibility. One other thing, I had a friend whose car was running hot, and it was because he had forgotten to put the thermostat back in when he changed water pumps. It will run real hot, if it does not have a thermostat..

That's as far as my thinking goes. But I agree with you, you will find out what the problem is, just be sure to share it with us.

Bill Seifert

1983 944 Race Car

 

Huh?

 

CCCP, Yeah, wierd as that sounds, it will. We were at St. Louis a couple of years ago, and a friend was having an overheating problem with his 944. It was hot as heck, and someone suggested getting a thermostat that opened at a lower temp. So we went to Auto Zone, and surprisingly they had one. We went back to put it on, and when we started to install the new one, we discovered, when he had put the engine back together, he had forgotten to install the thermostat. We put in the new one, and voila, it didn't overheat anymore. Someone told me that it was because the water cavitates without a thermostat. I honestly don't know, I've never had the problem, I have a turbo radiator, and a stock thermostat. My car always runs cool. I only use the fans if I am idling for a long time.

By the way, he got the pole the next morning, and blew his engine into a million pieces on his last lap. He loaned me his new tires, and headed back to Nashville, and I won the race. Wierd but true.

Bill

 

The thermostat problem is not from cavitation. The thermostat in a 944 open water flow to the radiator, just like every other car out there. It also closes flow to the heater bypass. If you leave the thremostat out, and thus both passages open, the pump is not able to create a pressure difference accross the radiator ==> no water flows though the radiator ==>> it gets hot inside.

As to the high temp readings. They may be correct. If there is a good (bad?) ammount of oil in the coolant, it will tend to stick to stuff and keep the water away. Oil is not a very good conductor of heat, so the engine retains it's heat and cooks. Happened to my Sable, but it was my Sable, so I didn't care. Hope you get the 944 sorted out.

 

I have a question about the pressure you are talking about........The thermostat is a dual release valve on the 944’s. The first (large) allows water flow into the heater pipe and the block. The second from my understanding releases water into the block when the heater flow is stopped.
If small holes are drilled in the thermostat (old racers trick) to have continuous flow, in reality this would do nothing but keep water in the block and head. Most racers run the heater tube straight to the back of the head which in turn would eliminate the need for a thermostat at all. I maybe way off based but I have been running my track car this way (holes in thermostat) for years with no issues. How would this be different in a street car if the heater core flow valves are closed at the back of the head and the water flows from pump to block to head to radiator?
All that really counts right now is the track can is running great and we are racing the double SARRC at Moroso in three weeks……………my daughter can drive my wife’s car until I can figure all this out.

 

hrsteel

Thanks for clearing that up. Jim, hope you find your problem.

Bill