Mechanic says it’s not the head gasket.

[87 Supra]

Originally Posted by igosaur

I had the same problem as you for months and yes, it was driving me nuts as well.

Everything suggested that it wasn't the head gasket, exhaust looked fine, no water in the oil and vice verse.

The first thing I did was change the thermostat and this seemed to work for a while but sure enough, not long after my problems were back. Each time it overheated it would dump loads of coolant in the expansion tank and sure enough, the next morning it was back in the radiator.

Eventually I have come to the conclusion that it was a succession of dodgy hoses. Each time I had an overheating problem I would listen carefully under the bonnet, with the engine off of course, and more often than not I could hear a hissing sound.

I have now repaired or replaced at least 4 hoses and changed the clips on countless others and, touch wood, no more problems.

It just takes a small split in a hose or a badly fitted hose to stop the whole system becoming pressurised properly and so it boils and either pops a hose or dumps coolant into the tank.

I also did an oil change and added some oil additive to keep the engine as cool as possible.

Thanks! I will try that this weekend and see what happens.

[ddmcse]

watch the over flow bottle and keep fluid in it

if you have to keep filling it on a regular basis ,,, guess what
you have a bhg and you can continue to drive for thousands of mile this way before you finally have to throw in the towel ...

[ethan12510]

Originally Posted by ddmcse

watch the over flow bottle and keep fluid in it

if you have to keep filling it on a regular basis ,,, guess what
you have a bhg and you can continue to drive for thousands of mile this way before you finally have to throw in the towel ...

its safe to drive with a bhg?

[IHateHacks]

An overflowing coolant recovery bottle = a blown head gasket. Its a sign that excessive pressure is entering the cooling system, and can you guess where that excessive pressure is coming from? I don't care who says otherwise. Come down to my shop and I'll pull your head off in 3 hours and show you your mangled, disfigured head gasket.

[ddmcse]

safe ?

you might pop a hose here and there but you can nurse it along for a long time

[IHateHacks]

You will also erode the coolant passages in the cylinder head from the corrosive exhaust gases entering the cooling system. And the water pump impeller will erode away as well. This is if you drive the car with a BHG for ANY length of time. If it gets really bad and coolant starts to enter the crankcase you will also ruin the rod bearings.

[linuxgurupodboy]

And even worse Hydraulic your motor. Thought I had a bad battery, but Water doesn't compress too well.