Need Help.... Wife will kill me if I dont get her car fixed...
 

The wifes is using my 82 300SD for the winter, and it started boiling over. Its the middle of winter so its not the weather. I just replaced the thermostat a few weeks ago. I was thinking it was the water pump but it the temp stays at 85-90 like it should, and I still have heat. It just makes a wired sound at the coolent tank and spits out a liter or so of coolent. I hope its not the water pump. Any other ideas would be great.
Thanks.
Jay

this may sound silly but, check and see if you installed the thermostat backwards.

Maybe has air in the system...suppossed to burp it like a baby. Some thing about parking the car at an angle with the nose higher than the rear. Other than that I don't know. be patient someone will help you.
I have always just let it run for abit standing there with the rad cap loose squeazing the upper hose. OF COURSE do only loosen the cap when the engine is cooled off.

Blown head gasket, engine compression is forcing the boiling coolant out of the cooling system. The failure in the gasket must have occured between the cylinder and coolant passage relief. A major repair if you're not mechanically inclined. Others may have more insight...

I wish you luck.

Ian White is probably right. But heres hoping that it is the wrong placement of the thermostat or an air lock. I have once done the last bit of filling through the heater hose that is attached to the head.
Given that you replaced the thermostat, it sounds like the overheating has a history. That could have caused a head gasket problem.

Maybe you should consider life insurance!! :D

Actually, life insurance is a bad idea. She'd think about how many pairs of shoes she could buy with that money.
If you know how to do it, get a cylinder compression check done. That will rule in or rule out a headgasket problem. A leakdown compression chick would probably be best. Make sure the engine is at operating temps before doing the test.

most shops today if you take a sample of the coolent to them can test it on the spot and tell you if the gasket or head is leaking compression as was said above - jz

Is it possible that the coolant is not in strong enough concentration for the temps you are seeing? Is it possible that coolant is freezing in the radiator, and preventing flow?

A long shot, to be sure. Buts its far better ( and cheaper) than replacing the head gasket.

Is there a DIY test kit you can buy for that?

its pricy from snap on - a good local shop should be able to help you out, most are in the customer service buzz and want to keep that open - jz

Yes there is a DIY kit. Mine has a liquid in a tube. You run the car with it stuffed in the rad where the cap goes. If it changes color it indicates a leak. The old time method sometimes work. look in the rad with the car running and if you see little bubbles you have hot gas escaping from the head gasket into the water jacket. Thanks

Forget all the coolant testing and compression testing. Ask a shop to do a coolant system pressure test. It's simple to do and will tell you immediately if you have a compromised coolant system. You can DIY this if you have the tool. The tool consists of a special coolant tank cap with a short hose connected to a smallish bicycle type hand pump and a pressure guage. You fill the system, install the tester cap and pump up the pressure to about 15 PSI and wait several minutes to see if the pressure drops. No drop in pressure means no problem. A drop in pressure means there is a leak and it's up to you to figure out where the water/coolant is going. A head gasket leak will usually end up in one or two cylinders and will show as steam coming from the tailpipe after the test. Do this on a cool engine NOT running. You can sometimes hear the leak if it's bad enough.

Thank you so much everyone. Will give a few of thoes ideas a shot. Oh My.... a head gasket would suck....LOL

If...
 

If it's a blown head gasket, even in the beginning stages, I think you would smell a problem from the exhaust fumes. Sweet smell would be a head gasket problem.

jeff

This test will only diagnose that there is a leak somewhere in the cooling system. It will not tell definatively that there is a crack in the hear gasket. However, start with the easiest thing first. Check to see if you put the tstat in properly, and check to see that the new one opens properly.
You might also want to see if there is a blockage in your radiator.... That could cause the problem...