ShortyPH

OK so my car is a 92 sc400, it never ran for good since it broke down 5 months ago. I changed the radiator at one point and I had overheating problems before this. (smoke coming out of the hood, etc, but headgaskets are good)

What I found in a radiator pass was a pile of junk accumulated in a small pipe going from the bottom of the coolant reservoir to under the engine thermostat.

It was blocked for about 4 or 5 inches in the pipe, thick sludge that I removed with a metal brush.. only way I could get it out thats why the engine overheated.



However, the engine always overheated after the radiator change and coolant passes cleaning.


Could it be possible that some VERY old coolant (I don't know when the prestone was last changed... but the car was in a very bad state when I bought it) is stuck in the engine internal coolant passes.

I used radiator cleaner 3 months ago and the problem did not change. Is there a solution for this or I need to remove the engine head and take a look inside and change the headgaskets at the same time... do a port and polish maybe that would give some HPs too.

Thanks

attzor

iTrader: (1)

Is there any smoke? drain all the coolant and refill it, it will take 3+ gallons, I did my water pump and overheated because I didn't realize that it took so much coolant, just make sure its full.

ShortyPH

It is full I have looked over that for more than 2 or 3 months and the level is perfect, all the coolant hoses are clean.

I'm starting to doubt the engine internal coolant passes are clugged up because I remember when I changed the coolant I was pouring it into the reservoir and all the old coolant would come out into a container on the ground... not too sure.

What makes me think that something is not OK is that the big principal hose on the radiator that goes to the motor builds A LOT of pressure and wants to blow out after letting the car idle or run for more than 15 20 minutes. The radiator becomes extremely hot too... too hot.

Maybe the thermostat does not work and doesnt open up when it reaches it's temperature? There's no check engine light or whatever. Don't know whats going on but for now I cannot use my car.

I did not let it heat up so much yesterday but when it did smoke the smoke was coming from the bottom left in the rear of the engine bay.

Maybe it is the radiator cap too but the extra coolant comes out of the overflow hose I think the cap is doing it's job.

The water pump never been changed but it does not leak can it be defective which would cause coolant overheating or any blocking into the piping...?

cbrasian

cooling system water pump radiator fan and fan clutch radiator and thermostat coolant temp sensor any of those can cause your problem your gonna have to check them all to make sure in working order eventually you'll find the problem

ShortyPH

Is the hydrolic fan supposed to run very fast when coolant gets hotter, I swapped mine on the new radiator but it seems to just go at one speed...

The temp gauge in the car is working good does that mean there can be a problem with the temp sensor anyway?

In this case my guess would be the thermostat cause there is a huge pressure build up in the system. Is there any way to test a thermostat or a way to see if it works properly.

ShortyPH

Can a water pump be bad even if it makes no bad bearing noise and does not leak? I really want to keep that car and now it is worth nothing because of this overheating problem.

Last time I took it I looked if the thermostat hose was hot and it seems like it was at a normal operating temp. I will take a look at the lower radiator hose if coolant pass normaly.