20vt. 1 full day on the road = head gasket gone!

I've just had my 20vt conversion back on the rolling road, all running sweet at 210bhp- which was amazing for the day I spent in it!!!

The head gasket has now gone after an hours commute to work and back in it. Is this something I can expect going alot with running that power in an AEB, or is it more than likely down to the fact the engine has been stored and not ran for over 3 years? Just preparing myself really for rebuilding it, giving it some beans down the road, and the gasket going again.

Bad luck mate. Could be a few reasons why it's gone. Do you know the history of the engine and has the mileage been verified?

Could be a storage thing? You gonna do the repairs yourself?

yeah first step we need to find out why it went, the hg on 20v lumps are not known to be weak so I wouldn't say that was the issue.

how was the coolant temp? the waterpumps are a known issue so that could be the reason it went

Yeh gonna carry out the work myself mate. I was told the mileage was around 80k, and it has been stored for 3 years if not longer!

The coolant temp was around half way on the gauge John, how would I be able to test the water pump? Really dont want it going again if I spend hours if not days replacing it!

if in doubt replace it basically

Anything else it could be? My pipe routing should be ok, as I've been driving the car for a while now and havent experienced any problems with it

how have you routed the matrix piping? did you fit some kind of bypass pipe as per factory mk1 so coolant can still flow out of the head when the heater valve is closed? this is often overlooked...

I've routed it, as the picture in this thread mate:

http://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=big-block-injection_2%2Fcoolant-lines

No theres no bypass, would this have created the problem?

its possible, if you look at the side 20v flange feed to the matrix when you block it off this may stop coolant flow out the side of the head to the waterpump.

if you look at a mk1 the side flange has an extra pipe to the metal hose, so if you block the matrix off coolant will still flow out the side flange

but then again there is an oil cooler feed from the side flange, that might be enough?

I mean the car has been running on the road like this for around 3 weeks. Its just since it has been put on the rolling road and now has some serious power behind it that it has gone!

tbh it could just be the hg was less than optimal, once you put the extra power in it has popped.

basically you need to take the herad off and have a look, see how it has gone. ideally get the head checked for flatness too

Yeh I will do John, I'll let you know how I get on! Cheers

make sure you fit a metal impeller water pump. like john said hg could of been on last legs and more boost and heat killed it.

i only fit genuine vw pumps now, they carry a 2 year warranty and after speaking to vw technical im loathed to fit aftermarket pumps with metal impellors,they are hard plastic for a reason,when the bearing in the pump collapses the impellor then hits the block and in a quite a few cases cracks the thin casting,the plastic impellor just shatters protecting the block,thats why the vw men stick to the plastic and so will I 8-)
Bert

even worse case with the metal impellers it could jam and shred the belt then bend all your valves, with plastic as above it'll shatter and worst case cook the head much cheaper to skim than replace valves or entire head

rubjonny said

even worse case with the metal impellers it could jam and shred the belt then bend all your valves, with plastic as above it'll shatter and worst case cook the head much cheaper to skim than replace valves or entire head

Aeb engine has external waterpump , so this is not a issue on this engine.

i read that its best to use a metal water pump. less prone to fail. oh well its on now

Right guys, I've been checking the car over for the head gasket going before I strip it down. Heres some things I have found:


The white smoke isnt bad all the time, and ran without any smoke for around 10mins.

The PCV valve is pressurising and if I cover up the outlet from the crankcase, it seems so smoke alot more.

There seems to be no mixing of fluids in either the sump or radiator, and theres no bubbles appearing at all within the radiator.


Whats anybodies verdict to this, does it still sound like a head gasket issue?

mark83 said

rubjonny said

even worse case with the metal impellers it could jam and shred the belt then bend all your valves, with plastic as above it'll shatter and worst case cook the head much cheaper to skim than replace valves or entire head

Aeb engine has external waterpump , so this is not a issue on this engine.

its a referral to the impellers and the material they are made of.

yeah sorry i was assuming internal waterpump!

try running the pcv to breather atmosphere if this is possible with the 20v(?) see how it is.

compression test might be an idea, do a wet and dry test. maybe the rings have gone if its breathing excessively from the pcv?