Recently the radiator went out on my 94 850 turbo. Had it replaced. Overheated again. Under the hood coolant had spayed from the tank. Replaced cap and thermostat. Still spray and overheating. Could it be the coolant sensor or a clog in the system. What else could it be?

 

Did you watch it spray from the tank? I would maybe check all of your coolant hoses, a smaaaaalllll crack will spray coolant everywhere. I had the problem a little while ago.

 

Yes, I popped the hood and let it idle. Saw it coming from the tank. It was a slow bubbly seep around the cap at first like it was not sealed all the way. When you drive it and accelerate that is when it sprays it the engine compartment.

 

Huh. You got some pressure building up in there then especially with a new cap on there, I've never had that happen to me so I'm not exactly sure, wait for some pros to get on a little later.

 

I would first check the thermostat. If it's stuck at full open, coolant rushes through the radiator so fast that it doesn't have time to dissipate heat (knowledge given to us by Tech). Then, make sure that the electric cooling fan turns on when it should.

I would then have the cooling system pressure-tested, and have the engine compression-tested.

Ignition timing issue does not usually apply to modern cars, as the timing is controlled by the ECU.

I had the same issue, except mine was due to over-filling the reservoir. I followed the correct procedure, which is to fill the reservoir to FULL mark when the engine is cold. After the issue, I decided to fill the reservoir only about 1" under the FULL mark and the issue was gone.


JPN

 

I hope you are not driving the car like this. It sounds like the thermostat is suck open or closed. You should swap that out first and then take it from there.

 

make sure the thermostat isnt in backwards/upside down... saw one guy do that lol

 

You may want to have the system pressure tested...to be honest, sounds like you have a blown head gasket. If the gasket is blown you will develop higher than normal pressure in your coolant system causing leaks to be exposed. The pressure will leave wherever it can. You overflow cap can handle around 14 psi...the pistons will put much more than that in your system. Start your engine (cold) and put your hand over the overflow, do you feel pressure building?

 

No, I am not driving it. Can't drive it too far before it starts to overheat anyway. I will check the thermostat again. Maybe the new one was faulty. Will check the pressure on the tank also.

 

just for testing. remove the thermostat and see if you still have an issue