I just bought a 525i 1992 a water pump problem, but the engine was running great. After replacing the water pump thermostat, I heard some intake manifold sound coming from under the car. I found out that the fan clutch and radiator were bad, I got them changed, I then change the engine oil.

The noise still persist and sound like there is a whole in the muffler, but when I look under the car I saw the pipe from the resonator to the catalytic converter red hot, I turn off the engine. The next day I started the car I found out that the noise was still there and heavy white smoke coming from the muffler. At this point I am a bit skeptical whether the head gasket is gone or the resonator and catalytic are clogged. Any help is appreciated. Thanks in advance.

1992 BMW 525i
1995 Ford Ranger
1994 Lexus LS 400

Could be head gasket. White smoke usually translates into coolant getting into the engine. Try looking at your oil more closely to see if you see any mixture of coolant in there. Try looking at your coolant fluid too. Coolant usually looks like chocolate milk when oil mixes with it.

Might want to have your car put on a lift to see where the noise leak is coming from.

The Antifreeze looks good no oil mixed and the oil is in perfect condition. I feel that the resonator and the cat might be clogged because of the noise that is coming from under the engine and there is a leak in the muffler. I will get the car to a muffler shop to further diagnose the problems.

yea i've heard that if youre burning some cooant (white smoke) that it may actually cause carbon deposits in the cat, causing it to back up and get red hot.

this question might be useful to the thread.. could there be any other explanation for coolant getting into the cylinders other than a bad/leaky headgasket or warped head?

It sounds like your timing may be off. That would explain the noise and the red hot cat. Does your car feel especially sluggish?

A red hot cat coupled with white smoke to me means you've got way too much fuel being dumped into your car. Yes, black fuel means you're running rich, but fuel that hasn't been ignited, but just vaporized and pumped through the engine will look white. I'd check for a bad injector or a bad pressure regulator, put a meter on your o2 sensor and see if you're way rich all the time.

The car is still started ok but the smoke is coming out heavily, the muffler has a leak on it. I found out that the cat is no longer burning hot. I don't know what to do. Thanks for your response.

Does the white smoke have any kind of smell to it at all?

disconnect exhaust at the cats, and run the car. This will tell you if the cats are clogged.

Running rich will give you a light gray smoke. And you should be able to smell the gas.

Do you get a CEL?

I have to agree that it sounds like a blown head gasket.

Send an oil sample in to find out for sure:
http://www.blackstone-labs.com/

It is well worth your $20.

The oil has no antifreeze in it and the coolant has no oil in it also. The smoke smells like gas. The problem stated right after the cat got red after the oil was changed. I will update you guys on tuesday when the cat comes and puts on.

it's good that it smells like gas.. my headgasket is blown/leaky and believe me, you do not want to smell the white smoke that comes out of it! It's one of the weirdest smells ever

After the cat being installed I started the car for the first 15 minutes there was no white smoke but after I drove the car for a good a 1/4 mile the white smoke came back and suddently the coolant level + owner's manual, I stopped the car immediately. I re-started the car over to make sure that the white doesn't show anymore, but unfortunately the white smoke re-surface right after I start the car. I am waiting for your insights fellows. Thanks