Sudden overheating.. ideas please!

[monsta]

Update for anyone interested, going into my trusted independent garage (not VW!) for thermostat and housing replacement + Water pump (while they're there since I'm over 60k now).  Total price £360 inc VAT.

[cossiegaz82]

I don't know what it is with VAG but they have to have the poorest water pumps known to mankind!

It's bad when aftermarket water pumps turn out to be better than the genuine VAG water pumps! I used to work as master tech at a Seat dealer and we used to recommend replacing water pumps during timing belt changes with an aftermarket pump as the impellers were made of metal rather than the crappy brittle plastic of the genuine pumps that used to break!

Over 10 years on they still have awful issues with water pumps! You'd have thought they'd have sorted themselves out by now!

[mcmaddy]

VW did go to metal impellers so they've obviously reverted back to using plastic ones.

[cossiegaz82]

Oh right, I didn't realise they went to metal but then I left VAG over a decade ago so a lot can happen in that time! 

I go to out to quite a lot of modern VAG cars with leaking water pumps (1.6 and 2.0 diesels mainly) but was out to 65 plate GTI PP in the next road from my house a couple of weeks ago for overheating that had just come out of a dealer for a new thermostat and water pump. I couldn't find a thing wrong with it though so whether it had an air lock or what, who knows! Lol!

[fredgroves]

Two colleagues suffered from broken water pump impellers on their 2014 GTD's. Plastic impellers...

[monsta]

I've been told the water pump is fine because I'm getting hot air through into the car on the heater, either way the amount of effort required to get to the thermostat housing, I'll spend the extra £60 for the water pump while they're there.

[mcmaddy]

Better safe than sorry.

[SabeMK7]

Just resurrecting this thread, my water temperature gauge sky rocketed this morning after sitting in traffic (Had ACC sensor intermittent sensor errors  in the past few days too) and I got a check engine light and warning come up saying I shouldn't go above 4,000 rpm.

My OBD Eleven reports the following codes;

P268100
P255600
P00B700

The first one was logged as malfunctioning 16 times so guess that's the real fault.  Myllermn was it just the thermostat or was the water pump replacement required?

Hey - I had the exact same issue coming down the A40 from London today. I had code P255600 come up first then followed by the other two. They're showing up on the OBDELEVEN app.

Can I ask, what was the final diagnosis and what parts did you get changed? I assume you have a MK7 GTI too? Mines a 2014 with c. 48k miles.

Any advice welcome.

Sabe

[Blades72]

I’ve just recently had the ACC error and engine management light come on, on my 13 plate. Turned out to be the water pump, so had to be replaced. Worse thing is the car goes in a few weeks as p/x against a new 7.5 PP so I’m out of pocket rather than the dealer. Timing not great!

[monsta]

Just resurrecting this thread, my water temperature gauge sky rocketed this morning after sitting in traffic (Had ACC sensor intermittent sensor errors  in the past few days too) and I got a check engine light and warning come up saying I shouldn't go above 4,000 rpm.

My OBD Eleven reports the following codes;

P268100
P255600
P00B700

The first one was logged as malfunctioning 16 times so guess that's the real fault.  Myllermn was it just the thermostat or was the water pump replacement required?

Hey - I had the exact same issue coming down the A40 from London today. I had code P255600 come up first then followed by the other two. They're showing up on the OBDELEVEN app.

Can I ask, what was the final diagnosis and what parts did you get changed? I assume you have a MK7 GTI too? Mines a 2014 with c. 48k miles.

Any advice welcome.

Sabe

Thermostat housing and water pump in the end. Basically one unit so not a cheap exercise.