as the title says, how do you tell, my header tank was overflowing on monday. Took it to the garage and they chemi checked it and said headgasket had blown. Can you argue with that? I ask about a compression test, he said it wouldn't always show. The head was rebuilt and gaskets replaced about 40k ago. Wat u think?? Today I had it running on my drive for about 45mins and there was no problems.... heater kicked in, no overflowing what so ever. I had my antifreeze changed last thursday, he pulled the pipe off of the bottom of the header tank, and drained it off, put pipe back on and refilled. U think maybe an airlock?? But chemi test says its borked! Help
If it's fine now it sounds like it wasn't bled properly and had an airlock as you suspect. Drive it for a bit but keep an eye on the coolant level and temp. If you're still worried, check for the coolant smelling of exhaust, coolant loss without external leakage signs, damp plugs and piston crowns after it's cooled, excessive steam from the exhaast etc.
Check the oil give it a smell and check for water "bubbles" on the dip stick. Should give you fairly conclusive verdict.
Only if it's gone between the oilway and the water jacket. To give the symptoms described it needs to have gone between a cylinder(s) and the water jacket.
surely if its gone it would fire out of the header tank reguardless??? if its gone water-piston, if its water-oil then ill get more oil/water level in the sump wont i??
I`d mark the water level (or top it up exactly to the upper mark) and try a new cap to be safe (or check the seal at least). Keep an eye on the header tank level and if it doesn`t move when checked (cold) after a few good runs it should be fine. If it`s a breach between cylinder/water jacket it`ll probably pressurise the cooling system and fire it out after 10mins or less of running (before the fan comes on).
Not necessarily. It'll only fire water out if has gone cylinder-water and pressurising the coolant. If it's gone oil-water you will tend to get water in the oil and the infamous mayonnaise. If you do get a little mayonnaise it can be just condensation and a good run normally clears it.
Take the cover off the right hand side of the coolant header tank, check for weeping, if so try changing the cap first, if it still does it afterwards, then the gasket is probably gone. Also check the coolant hoses after a short drive, if they are hard then this is also a sign of a gasket leak, pressurising the coolant system. Its very common for the gasket to go between no.1 cylinder and the water jacket on early vr6 engines. If the symptoms are as described, get it done, otherwise head corrosion will set in.
it is booked in to be done, but i went to another garage today and he said BOLOX its gone..... the header tank hasn't leaked since it did 1stly, the chap down the garage told me to clean the cap, and replace it, might be a pooy seal. But ive had it running for over 45 mins outside on the drive and there is no problems at all. How does that chemical tester work anyhow? The head wont corrode, you will just get combustion burns in the head and wont be able to skim it!
