Any ideas?

If I take her above 40mph the temp starts to climb from 90 degrees, but drops back and holds steady as I ease off. It hit the alarm at 70mph- thats what let me know.

Coolant and oil levels are fine, no leaks, no smoke.

Runs and idles as normal, no loss of power.

Engine 1.8T 150bhp, no mods. 02 plate.

No water in oil.

Do they still use the old style thermostats or is it all electronic now?

Could I have an airlock preventing the radiator topping up?

I am now leaning towards a water pump failure.

I have heard a few noises on startup recently that sounded like a belt slipping. Is this pump belt driven?

Is it expensive to replace?

Can I test to see if is working?

Cheers

Mark

No ideas anyone?

The garage can't fit me in until Thursday :(

They are Vag specialists and had not heard of anything like it. Why does it always have to be something complcated

These Skodas are not as reliable as I was lead to believe. I think I will be going back to a Japanese car next time. Not had so many problems since owning a D reg Astra.

Another Friday afternoon car maybe?

I have heard of similar symptoms involving a faulty water pump. If it is the pump, it might be a good time to get the cambelt and tensioners changed if they haven't been already.

Thanks Denis

That is all I think that it can be.

If the pump stops completely would the car overheat at low speeds or idle? or does the water circulate by convection and pressure to some extent?

do the fans kick in?

if not try checking the connection for the fans at the bottom right of the rad as you stand in front of the car looking into the engine bay, can work loose with dodgy rad mounts...

I have not checked the fans, but at 70mph and 5 deg C, I thought there would be enough cold air rammed against the radiators to keep it cool.

It does not overheat at idle anyway, just at sustained 40 mph+

I had similar symptoms in a MK2 Escort when the radiator was only half full. Damned head gaskets

Thanks for the comments though :thumb:

Yes they do have old style thermostats, and the water pump impellars brake on the 1.8 ts, meaning the outer belt dreiven part spins and looks normall, but inside its not spinning! Thats the worse case, it could be something as simple as a faulty temp sender just making you believe its getting that hot. Good luck

Impellor has fallen off the water pump for sure.

Well they had a quick look at her today, but did not cure it.

The fans did not come on when the car started to overheat, so they wired them to be on permanently while the ignition was on.

Went for a drive and she still overheats. The radiators were only warm to the touch (which may explain why the switch did not activate the fans)

The skoda garage thinks head gasket, but it doesn't add up.

It is back in on Monday at a specialists. It must be the water pump.

I had something similar on mine on a Ring trip. Turns out one of the fans had got a blown motor (there are 2, a big one and a little one). The big one on mine went and was replaced under warranty. Was fine when at a steady state cruise, but when you gave it some beans it started to overheat. Tried wiring it permanently on (as you did) over the phone with my dealer, but it didn't work :(

Both fans are running fine, I just don't think the coolant is circulating through the radiator very quickly.

Other fault I had, also done under warranty, was a blocked/perished coolant hose - goes into the side of the engine IIRC

That really sounds like the water pump, had exact same symptoms on a mates car

(A knackered old ford).

The water pump appeared to be turning, but nothing was moving through the circuit, so as soon as you needed the cooling it wasn't there.

That or the thermostat isn't working, but then that would eventually show up after a long idel too.

Yeah, agree that water pump has broken - especially if fans work, radiator in/out is not hot enough, and thermostat is triggering the alarm: the pump is not pushing the hot water to the rad, so it never gets a chance to cool.

As people have already said, labour-wise, it usually makes sense to get timing belt, tensioner, pulley, etc all done at same time.

Don't know your mileage, but most people get belts done from 60k miles onwards on the VAG 1.8T engines. Safe is around 60k, tempting fate is around 80k, asking for a smack is around 90/100k.

Cheers

Mine is just coming up to 50K, but the log book says it has already been replaced. I wonder what broke that time?

Back in on Monday, all fingers crossed that they can fix it. It is not about the money now, I just want my car to work. That is unless it is the head gasket, I dread to think what that would cost to fix :(

I have just spoken to the garage.

The impellor has come off the water pump.

Getting the belt and tensioners done at the same time (I don't tempt fate)

£280 plus vat for the lot.

Oh well, its only money :cry:

Well it's not that bad, I mean £280 now, or 2.8k if it all went wrong.

I think that's quite a good price, and it does make sense to get it all done at the same time. I think I paid 330 when I had mine done on an Audi a few years ago.

I thought so, its happening a lot, especially on vrs. Its vary rare head gasket to go on them. Defently do the belt tensioners and rollers at same time.

The old water pump had plastic impellors which had snapped off the axle.

The new pump should last longer as it has brass impellors.