Coolant Loss = Head Gasket Failure. 95000 Mile 1.9 TDi 130 VRS

[iamrcb]

After these two threads on my coolant loss:

http://briskoda.net/forums/topic/158253-still-cant-fix-my-vrs-coolant-leak-problem/

http://briskoda.net/forums/topic/155436-still-cant-solve-my-coolant-leak-problem/

All signs point towards head gasket failure that is letting exhaust gases into the coolant system, pressurising the coolant system and pushing the coolant out of the top of the expansion bottle.

£500 to £600 to get it fixed at a good VW independent. Ouch, but worth it as its a great car.

I've read lots of similar posts on other forums going back a few years. All but one fails to get to a conclusion, so I'll summarise my issue below:

Symptoms and Findings.

- 2004 Skoda Fabia VRS 1.9 TDI 130 (ASZ), 95,000 miles

- Coolant leak only from the top overflow hole (under the plastic flap on the expansion (coolant) bottle)

- Only leaks under high engine load (above 70mph)

- No sign of oil in the coolant bottle, no sign of water in the oil

- Coolant bottle replaced. Cap replaced

- No signs of exhaust gases in the coolant bottle when testes at the garage (i.e. sitting still)

- Water pump is ok

- Thermostat is ok

- No overheating ever (never above 90 deg)

- Heater working ok

- Big release of pressure every time the coolant cap is taken off, even when engine is cold

- All the power is there, drives well

Supposed to be more common on the 115bhp TDI PD according to other posts, also on the 2.0 140bhp TDI PD, but not so on the 1.9 130bhp PD.

A question I asked my garage is when a head gasket is fixed is it likely to fail again? They said they've never had one return.

In on Tuesday for a few days to get it sorted

Edited 28 April, 2010 by iamrcb

[RADIOTWO]

Hi Again

I know you have mentioned about the head gasket, and they have checked for gases in the water but what did they do ?

If they have not done the test correctly it could be a cracked block, and pressurizing back into the water system.

My son is having similar problems on his 115 TDI, he looses about a bottle full every couple of days or so, so I am keeping a eye on you posts

Radiotwo

[Jabbasport]

Sounds silly, but something to try is a 90 degree turn on each head bolt.

We had this on our standard octavia years ago, screwing the headbolts down fixed it..

Chances are the head bolts are stretching slightly over time?

Kev

[rwbaldwin]

...Coolant leak only from the top overflow hole (under the plastic flap on the expansion (coolant) bottle)...

My guess from the above, is that you have a faulty expansion tank pressure cap or even a faulty tank.

Any pressure test wouldn't necessarily show a problem as the pressure tester replaces the cap.

[thirty3]

Have not read other two threads.

But did they do a sniff test as that will tell immediately if exhaust gasses are in coolant.

[iamrcb]

Replaced cap, replaced tank, same problem

Previous sniff tests have not found anything but as I said it only happens under high engine load (70+) even after 50 mile trips at 60mph

Coolant is not leaking out elsewhere, oil is not leaking into the coolant.

Edited 28 April, 2010 by iamrcb

[thirty3]

Ah sorry didn;t read the OP properly.

This is a tricky one because the coolant system is supposed to be under pressure. It helps the coolant to stop boiling. Now whether you have too much pressure I dont know if there is a test for that ...lol

[radioone]

Hi Again

I know you have mentioned about the head gasket, and they have checked for gases in the water but what did they do ?

If they have not done the test correctly it could be a cracked block, and pressurizing back into the water system.

My son is having similar problems on his 115 TDI, he looses about a bottle full every couple of days or so, so I am keeping a eye on you posts

Radiotwo

Mine is the 110TDi, it is the none PD Engine, looks from what has been put that it is more common on the PD Engines!

Will keep an eye on this thread though to see the outcome!

[iamrcb]

I typed out a good long response but the page crashed and lost it so here's the ultra short version

Head has been skimmed as it was warped, something about "12 thou" (0.3mm) out. Being put back together tomorrow.

Big whacking great bill due tomorrow

I'll be asking the following questions

WHAT CAUSED IT?

IS IT LIKELY TO HAPPEN AGAIN?

HAS THE SKIMMING ADVERSELY AFFECTED THE CAR LONG-TERM?

WHAT CAN BE DONE TO PREVENT IT IN THE FUTURE?

Edited 6 May, 2010 by iamrcb

[anewman]

There's sort of like a designed in amount that can be skimmed off the head, 0.3mm won't cause any measurable issues I'd imagine.

The main thing that needs to be done to prevent it happening again is to have the job done properly (skimming is doing it properly) and the other main thing is to ensure the coolant system is in tip-top condition, and check the coolant level regularly.

[MoggyTech]

Skoda specifically state that the reworking of diesel cylinder heads is not allowed.

[anewman]

Skoda specifically state that the reworking of diesel cylinder heads is not allowed.

eek that kills off my post then

[DEAN0]

Skoda specifically state that the reworking of diesel cylinder heads is not allowed.

I would have guessed the same too.

The compression ratio and the squish band will have been changed by skimming so the timing will now be out (compression ignition)

[iamrcb]

I've read many many forum posts about skimming a PD TDI head, some say its fine, some say that the world will end if you do it.

The garage has been fixing VW's for 30yrs including countless TDIs, so I trust their knowledge.

[iamrcb]

I've got the car back from the garage.

£590 later it now runs perfectly with no coolant leaks and no pressurising of the coolant system.

Garage said that when they looked at the head there were two clean spots under the gasket, must have been where the leaks were. After skimming the performance and economy is certainly all still there.

Lets just hope that there are no more surprises for the next 30k miles at least, which is about a year from now.

Great to have it back. They even washed it too!

[iamrcb]

I would have guessed the same too.

The compression ratio and the squish band will have been changed by skimming so the timing will now be out (compression ignition)

Garage said that the new head gasket makes up for the skim depth, hence timing and compression stays the same

[MoggyTech]

Garage said that the new head gasket makes up for the skim depth, hence timing and compression stays the same

Sounds like you have been lucky. There are 3 thicknesses of head gasket available. The factory measure the piston top projection above the block and select a suitable gasket to suit. If your car had the thinnest gasket, they could skim about 0.28mm and use the thickest gasket to compensate.

[iamrcb]

Sounds like you have been lucky. There are 3 thicknesses of head gasket available. The factory measure the piston top projection above the block and select a suitable gasket to suit. If your car had the thinnest gasket, they could skim about 0.28mm and use the thickest gasket to compensate.

apparently it was 12 thou out, so about 0.3mm

[MoggyTech]

apparently it was 12 thou out, so about 0.3mm

It will be fine

[mds]

I've got the car back from the garage.

£590 later it now runs perfectly with no coolant leaks and no pressurising of the coolant system.

Garage said that when they looked at the head there were two clean spots under the gasket, must have been where the leaks were. After skimming the performance and economy is certainly all still there.

Lets just hope that there are no more surprises for the next 30k miles at least, which is about a year from now.

Great to have it back. They even washed it too!

Hi same problem, could you tell me where you had the repair done ? thanks.

[iamrcb]

Hi same problem, could you tell me where you had the repair done ? thanks.

NG Motors Cardiff, Independent VAG specialist, £580 inc vat, in for a week in total. Did not have the timing belt and water pump done as they had been done at 60k.

[Matt K123]

Had mine replace under a used car skoda warranty, and performance and economy hasn't altered. First noticed a fault when i went to clean the expansion bottle cap (sad, i know) removed the cap, and a noticable hiss was heard, as thought the engine had just been turned off and the was removed, but i hadn't used the car for days. The car was then booked in, and the sniff test quickly diagnosed the fault - Head gasket. Water is still coming out of the bottle, but this is due to the cap being faulty as it doen't stay tight, so its going back soon to get a new bottle and cap.

Matt

[skod fab]

i have an skoda fabia 1.4 mpi the azf engine here in greece it runs normally but after like 15 km the temp light comes on and like drunk all the coolant i put in it the next day it didnt loose anything i figured it drunk it all when it was raining anyone have any ideas

[stewyvrs]

SOS hi I just purchased a 54 plate vrs with 110000 on the clock the coolant resivour lid has popped off and it was using coolant and lots of it! It's been remapped to 170bhp and I have no idea what's wrong with it :-/ also seems to b a smell of diesel in the cabin? Help please? How much could this repair end up costing me

[Juka]

Sounds silly, but something to try is a 90 degree turn on each head bolt.

We had this on our standard octavia years ago, screwing the headbolts down fixed it..

Chances are the head bolts are stretching slightly over time?

Kev

 

Will just mention this to my mechanic as I have exactly the same symptoms as iamrcb, but it's probably the head gasket and head machining for me also...