Cooling 348

92 348TB Checking cooling over flow tube leaks after each drive.Opened coolant cap and found brown like oil in coolant.(NO Leaks) But I want to do a coolant flush anybody know the best type of coolant and anything I should know to do the change.

Might be a blown head gasket, Pull the spark plugs and check them. Do a compression check

Ooooh man, not good! Yeah if you have brown oil in your coolant you may have a blown head gasket. You should also check your oil for signs of water in it.

Brown but not oil is corrosion--and this is not good.
Brown and oily is a blown gasket and this is even worse.

Check the oil for water, flush the coolant, run the car for 50miles and check the systems again.

Yes brown not oil.A friend has the sam car with brown also,so does anybody know the right way to do the flush,and what kind of coolant.

Thank You.

I use the Prestone pre-mixed 50/50 coolant.

The right way to flush the 348 system is to drain the system at each radiator, left and right side, remove your thermostat and plug the bypass hole that is underneath the normal thermostat location, and then pressurize water through your coolant fill cap opening until no more brown radiator rust comes out anywhere...

Then drain the water and refill with Prestone pre-mixed 50/50 green coolant.

And of course, remember to unblock the engine coolant bypass underneath your thermostat.

Now, with your ignition key turned to Run (not Start), set your heater to max high while you bleed your system (you'll just put a wrench to loosen the bleed screws on the right side of your engine bay on the black coolant pipes).

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OK, some car owners install coolant filters at this point. You might consider doing the same (less debris hitting your waterpump blades).

Some race-car shops also replace their solid black rubber coolant hoses with transparent FEP Fluoropolymer coolant hoses...this lets you see air bubbles so that you know where your hot spots are located and when it is time to bleed your cooling system...and it helps you spot rust/debris sooner.

Just some thoughts to consider.

thanks for all the info.