Coolant Loss on Passat Pd130

[UR-S4]

Get them to check the water pump impeller.They come loose prevent water circulation.It will thermosyphon as low engine speeds but under load cant keep up and the temp shoots up.often the heater stops working also.you can access the back of the pump by removing the thermostat an poking your fingers in and trying to turn it.Lots of people come to us and say ive read on the forums that the metal impeller pumps are better.They are NOT ! they are cheap quality & DO fail.

[Fat Audi 80]

It had a new waterpump 10,000 miles ago along with the cambelt etc. I have already discussed that possibility with my mechanic, and we sort of discounted that as the pump is so new. I will get him to check though....

Thanks,

Steve

[Fat Audi 80]

Get them to check the water pump impeller.They come loose prevent water circulation.It will thermosyphon as low engine speeds but under load cant keep up and the temp shoots up.often the heater stops working also.you can access the back of the pump by removing the thermostat an poking your fingers in and trying to turn it.Lots of people come to us and say ive read on the forums that the metal impeller pumps are better.They are NOT ! they are cheap quality & DO fail.

Give that man a prize!

My mechanic was loathed to take the head off and checked the 10,000 mile old water pump. The plastic impeller was spinning on the shaft. It now has a metal impeller type pump and is running a lot better, although the coolant system does seem to run at a slightly high pressure, so time will tell if this is the final fix.

I am very pleased the head has not had to come off, it has saved me ££££'s.

Cheers,

Steve

[dubmeister]

Sorry to be late to the game, but water pumps are notorious for failing! irrespective of mileage.............
Replaced cambelt/pump etc. recently on a pd130 passat.
Came back with coolant/overheating problems.
Long story short- impeller had become loose, car had done less than 3000 miles!!!
All genuine TPS parts fitted. Got new genuine parts fitted...again!!, car runs great again- customer not happy that new genuine parts had failed so soon.
Old pump sent back for warranty. I shall wait for the verdict, and then chase up the labour claim!!
Now remember this- certain vw pumps are exchange items!- go figure!!
Not just vw/audi related either, renault/vauxhall pumps have been found to be failing too. Have had cars in with strange metallic noises at idle, failed impeller causing noise but no overheating/coolant loss!!
Glad you got it sorted.

[Fat Audi 80]

Yes. We are sending the pump back for a warranty claim, but its 14 months and 10,000 miles, which we don't expect to win. I certainly don't expect to get anything for labour - 4+ hours....

Not very impressive design IMVHO....

[Fat Audi 80]

Pissed off today. It is still losing coolant under pressure when driven moderately hard. I put a litre in yesterday to top up the expansion tank and it is down to minimum again today. (30 mile trip)

Looks like the head will have to come off unless someone has got any bright ideas:

So far it has had:

Pressure test - no water leaks
Thermostat - Old one was locked solid
Water pump - impeller was spinning on shaft

Fed up.

Cheers,

Steve

P.S. I gave it a birthday and detailed it yesterday, it is looking MINT.

[johne]

Whilst I admit it looks like the head gasket is all that's left, given it's been apart so much I'd top it up again and give it a few runs before ripping the head off just in case you're working out the last of any air trapped in the system.

If it helps and I know this isn't your S2, the level in my S2 has always settled at just below the minimum on the expansion tank for years now.

John

[Tony Stark]

How long was the cooling system pressure tested for? did the pressure tester have a gauge on it that showed it to be holding pressure?

what about getting a block tester/chemi-test carried out on it to check for head gasket failure?

[mcandmar]

I had an 80 Turbo Diesel years ago that did the same thing, ran perfectly until you started driving hard, then it would over pressurize the coolant system, piss out all the coolant and overheat. Confirmed it wasnt thermostat or water pump and sold it as is with a head gasket fault, didnt have the money, patience or motivation to fix it at the time. Was either a failed gasket or cracked cyl head.

[Fat Audi 80]

Whilst I admit it looks like the head gasket is all that's left, given it's been apart so much I'd top it up again and give it a few runs before ripping the head off just in case you're working out the last of any air trapped in the system.

If it helps and I know this isn't your S2, the level in my S2 has always settled at just below the minimum on the expansion tank for years now.

John

Thanks John, I admire your optimism. I am going to see how it fairs over the next week or so. You can live with it, but you end up topping up coolant every 100 miles!

We shall see.

Apart from this, I absolutely love the car, it does everything we could wish for.

[Fat Audi 80]

How long was the cooling system pressure tested for? did the pressure tester have a gauge on it that showed it to be holding pressure?

what about getting a block tester/chemi-test carried out on it to check for head gasket failure?

A couple of hours and yes the gauge did not budge during the time it was under pressure.

Cheers,

Steve

[Fat Audi 80]

I had an 80 Turbo Diesel years ago that did the same thing, ran perfectly until you started driving hard, then it would over pressurize the coolant system, piss out all the coolant and overheat. Confirmed it wasnt thermostat or water pump and sold it as is with a head gasket fault, didnt have the money, patience or motivation to fix it at the time. Was either a failed gasket or cracked cyl head.

If it turns out to be the HG or a cracked head, I will fix it (or pay someone else as it happens) as apart from this the car is excellent. Mint condition and fully loaded. I could not replace it without spending a lot (more) money.

Cheers,

Steve

[Pirvu Eugen]

The heads are not soo prone to crack on this engines...but...because overheating..they deforme between the cylinders...
Remove the head...skim...exchange the injectors orings....and will work ok...
Goodluck!

[Fat Audi 80]

The heads are not soo prone to crack on this engines...but...because overheating..they deforme between the cylinders...
Remove the head...skim...exchange the injectors orings....and will work ok...
Goodluck!

Thanks!

[UR-S4]

a good check for head gasket failure is to check for cooling system cold.open the cap to nutralise the pressure in the system.use the car warm it up etc then allow it to cool again.if the system is still pressurised,when fully cold,then pressure is being introduced via a failed gasket / cracked head.very rare for a 1.9 tdi to crack a head.(unlike the 2.0tdi !) do beware of refacing the head only if absolutly ness as the valve seats req re cutting to lower the valves (they get a bit close to the piston crowns)