Hy everybody, I have a problem with my 87 951. When engine it's at normal operating temperature, let's say when I park after half an hour drive, it starts to leak coolant right after I turn the engine off for like half a minute and it leaks like half a quart maibe a quart off coolant. Coolant leaks on driver side right next to the front wheel. I also can see that the oil pan it's wet. What I did so far :
changed water hose clamps between aux pump and turbocharger
changed thermostat
changed turbo thermostat
bleed the system
changed coolant tank cap
changed thermofanswitch
cleaned water and oil radiators
I also found traces off coolant on bellhousing visiting hole cap, but only a few drops.

 

Is it coming out of the overflow tube? What does the temp on the dash show when you are seeing this leaking? Have you flushed the coolant recently or done any service that requires draining the cooling system such as replacing the turbo?

 

no it isn't coming from the overflow tube and yes I changed the coolant when I cleaned the radiator and changed the thrmofanswitch. The temp on the dash stays at the second white line in the middle ( 80 degrees C ).

 

your turbo pump could be finished. look at the pump and see if it leaks coolant next time this happens

 

Pick up a coolant system pressure checker. In the states, we can "rent" one by buying then returning it at local auto parts stores. They're intended for rental, but you basically put down a 100% security deposit for the tool.

Since it's leaking a decent amount of coolant, you might be able to find it by just parking the car, while hot. Then, after the coolant starts dripping, look for the active leak. The only draw back, over using the pressure checker, is having to feel around a hot engine bay.

 

Check the hose that feeds the metal pipe off the turbo, it is notorious for leaking. It tends to take enough heat where the clamp needs to be tightened every so often.

 

I think Paulyy nails it here. The turbo pump is on a timer switch that engages when the engine is shut down. You're only seeing the puddle form at engine shutdown, right? Fill system, run engine until hot (heater on, and heater off), check for leaks, then shut down and compare. If no leaks prior to shutdown, I'd bet a dollar it's turbo pump.

 

you can cause the aux pump to run by quickly jumping the DME relay emergency jumper described on the 5th page here. Just plug it in for a sec and then pull it out. It'll make the aux pump run for a bit. Might be easier to test that way than going for a drive and trying to make the pump run on it's own.

Also, I've had several of the old style (brown) expansion tanks crack right around the seam on the edge closest to the left headlight... When it cracks, it usually doesn't leak when it's cold, just when it's hot. Check around that area for stress marks in the plastic.

Hope some of that helps

PS: I just noticed that you said you're seeing some coolant on the bellhousing - check the hoses between the head and the heater core (and the heater control valve). Also, are you really sure it's not coming out of the overflow?

 

Hey everybody, thank you for answers. Good news, I've checked as you told me and found an cracked hose from cylinder head to heater valve. I didn't saw it early cause the crack was below the hose. I replaced it with an old one and fixed the problem until new one arrives.
Thanks again for help!

 

Awesome! Glad to hear you got it figured out!