Overheating!

[AlandAnn]

My bus overheated on my way home last week. Diagnosis was a faulty thermostat. Anyway, got a new one fitted and she ran fine all week until on my way home.
The hot air blower suddenly went cold and then the needle started climbing.
Maise is a 29 yr ld 1.9 wbx and so far I've had relatively minor issues with her.
Can any mechanically minded person on here give me any other ideas what could be wrong with her please?

[AlandAnn]

Just spoke to mechanic, he reckons it's the radiator. He has the old thermo that was rusty.Anyway he reckons £120.00 for the radiator and money for 30 mins work. How does that sound to the experts out there?

[California Dreamin]

The symptoms you describe are typical of a head gasket failure..

Martin

[chapperss]

Is the rad leaking? sounds like it had air trapped in the system to me after he changed the stat, if the heater went cold. make sure its properly bled before changing the rad. BUt if the rad does leak, £120 with labour etc sounds good to me.

[captain Byrne]

Just spoke to mechanic, he reckons it's the radiator. He has the old thermo that was rusty. Anyway he reckons £120.00 for the radiator and money for 30 mins work. How does that sound to the experts out there?

What does he say is wrong with the radiator?

[AlandAnn]

He thinks it's blocked up with crud and preventing the coolant from flowing through its cycle. I've changed the coolant twice in the last two years, don't know why I bothered. Any ideas? Weather's looking good this weekend as well.

[captain Byrne]

Doesn't sound right to me. If your rad was blocked it wouldn't just happen suddenly - it takes time. I'd be tempted to make sure the system is properly bled before you splash out £120 on a new radiator.
Is the mechanic who changed the stat aware of the difficulties you often get when bleeding a T3?

[AlandAnn]

He talks the talk. Not an expert myself so just relying on feedback from wherever I can get it.

[captain Byrne]

hhhmmmm, plenty of post on here about how to bleed the system properly. It's not really that tricky, even for a complete novice. Try that first but get a second opinion about your rad. I suspect it's fine.

[AlandAnn]

Just bled the bleeding radiator... had the Mrs sit and rev it for a good twenty minutes, and then I opened up the 13 mil bolt on the radiator...she hissed for ages and so did the radiator. I'll take her out for a ride in a minute to see how she goes.

[ajsimmo]

Compression seal (aka fire ring) on top of a barrel leaking, pressurising the cooling system with combustion gasses and forcing out coolant? Is the expansion tank overfull?

[AlandAnn]

Yes, the expansion tank is filled. I've taken her out and see seems fine, off to the Ben Aan tomorrow.

[California Dreamin]

Yes, the expansion tank is filled. I've taken her out and see seems fine, off to the Ben Aan tomorrow.

I think you're missing the point ^^^^^^^^^ when Andrew said is your expansion tank filling up. he wasn't asking if you filled it! is the tank behind the number plate OVERFULL due to what could be a failed top seal leaking.

Martin

[captain Byrne]

No offence but It's quite obvious AlandAnn aren't as technically proficient as some members here are, so phrases such as 'a failed top seal leaking' & 'Compression seal (aka fire ring) on top of a barrel leaking, pressurising the cooling system with combustion gasses and forcing out coolant' are probably as Greek as they get. First thing is to eliminate a possible crap mechanic who hasn't bled the system properly & is scratching his head assuming the radiator is blocked. AlandAnn, make sure you bleed the system properly. The top tank should be completely full & the bottom tank (behind the number plate) should be within the two marks on the tank. Run the engine, make sure the radiator gets hot & coolant seeps from the 13mm bolt at the top of the rad when you undo it. Take it for a decent run & keep your eye on the temp gauge. Have a good look for leaks everywhere, in the engine bay underneath & around the radiator. Check the level of coolant in the bottom tank (behind the number plate). If the level has increased dramatically then you may have problems. Otherwise, you're probably good to go.

[ajsimmo]

Can any mechanically minded person on here give me any other ideas what could be wrong with her please?

That's what I did. I don't dumb down, and try not to patronise, I just try to describe things simply and clearly. I assumed, as they won't be attempting the repair themselves, they'll go back to their mechanic and ask if the suggestion has any merit. He'll get it.

It's always risky to diagnose remotely, but I expect there was nothing wrong with the thermostat, or the radiator. The initial overheating and the more recent incidence are probably caused by the same fault. OP said it was fine all week, then heaters went cold and needle rose. This is typical of the fault I described, or as Martin said right at the beginning, "head gasket failure". I think most people would understand that expression.