Overheating

[seatkid]

You may not loose coolant, the pressure of the engine firing may be enough to breach the gasket, but the pressure of the coolant may not be enough. Sounds weird but it happens.

 

As for pressure in the coolant, the cap will let out excess pressure.

In my experience...(with other engines [sAAB])

If the head gasket leaks, the (hot) gas pressurises the water system, the cap blows off and this is where most of the water exits.....rapid overheating then follows due to low water....Its usually a dramatic sequence of events, as the leak almost always causes a rapid distortion of the head/block interface.

[MatTdi]

Well As I started this I better add some more info!!

 

I got a second opinion from a VAG specialist who confirmed that the head gasket has NOT gone, they had the test running for 30 mins and no change in color.

Also they confirmed that the most likely cause of the overheat at speed and no heating is the waterpump.

 

Its booked in for Friday to change belt and pump (with a metal impeller!!!), so fingers crossed 'till then......

 

 

Thanks for all your help and info so far

 

 

M@

 

PS DannyBoy, after speaking to the guys at the VAG specialist and the info from the guru's on here i'd put money on your water pump being stuffed.....

[Masked Marauder]

Well As I started this I better add some more info!!

 

I got a second opinion from a VAG specialist who confirmed that the head gasket has NOT gone, they had the test running for 30 mins and no change in color.

Top banana! The chemical colour test is the best way to look for a gasket fail between cylinder and waterway.

 

If the other garaged had done it it would have been clear that the problem was not the gasket, so it really makes me wonder if they did do it and the mis-inform you. It would have likely been a

[MatTdi]

Well I can honestly say that I now would not trust the original garage as far as I could throw my car!!!

 

I reckon they must use the headgasket as a money earner... they collect the car do some "tests" and tell you the bad news, then say they would not be prepared to drive the car back as the gasket has gone......

 

if you didn't know any better you can see how it works!!!

 

 

Regards

 

M@

[GSMGuy]

Mat - just a thought, I had a similar prob with a couple of 405's a few years back - they only overheated at speed..

 

Turned out the rads were partially clogged with silt from poor quality antifreeze... They were about

[Danny Boy]

MatTdi,

 

Great thanks for the info, will now persue the garage and get it sorted.

 

Great relief its not the head gasket!!!

 

I'll keep you updated on my progress

[MatTdi]

Well its thanks again to this forum!!!

 

I have finally had the waterpump replaced, upon removal the impeller remained in the engine as it had fallen off.... what a great peice of design work by VAG. (its a plastic impeller pressed on to a knurled shaft).

 

So it only taken me 3 weeks to get sorted, 1 cowboy with a head gasket claim, 1 mechanic who rescheduled and then didn't show!!

 

I have now found a good reliable mech who is local and will be getting my work from now on!!

 

 

I will post a photo of the pump and impeller tomorrow to give you all an idea....

 

 

THANKS AGAIN (yes I meant to shout it)

 

M@

[Masked Marauder]

I have finally had the waterpump replaced, upon removal the impeller remained in the engine as it had fallen off.... what a great peice of design work by VAG. (its a plastic impeller pressed on to a knurled shaft).

 

 

That is a common practice now, and not limited to VAG!

 

I have seen a few Vauxhall ones that have done the same.

[seatkid]

Danny Boy take note....

 

So now we know, VAG design standards are rapidly heading for the dustbin.

 

So...... lets add to the list.....

 

Water pumps

tensioning rollers

tie rod ends

arb links

MAF sensors

[long list of a/c components]

.....

.....

.....

[Masked Marauder]

I think VAG have been resting on their laurels for quite a while now, and before too long their perceived build quality status is about to come crashing down.

[Danny Boy]

Dont worry seatkid I have taken note. Wife goes in tomorrow to a C section so another addition to the family tomorrow.

 

Will then book the car in to get sorted!!

 

Cheers MatTDi :(

[Guest vr6galaxy]

Dont worry seatkid I have taken note. Wife goes in tomorrow to a C section so another addition to the family tomorrow.

 

Will then book the car in to get sorted!!

 

Cheers MatTDi :(

C section? :o the amount of times she's popped em out before Danny it's more likely to be H section, while she's there get them to put in a zip for next time :(

[seatkid]

another addition to the family tomorrow.

 

Will then book the car in to get sorted!!

While you're in the hospital why not book yourself in and get whatever's causing this recurring problem sorted..... :(

 

Hope it all goes well and get that booze chilled...... :(

[MatTdi]

Guys as promised.... the great example of VAG design....

 

http://img.photobox.co.uk/895200112ab10e507846bf182fa2bc42c050d1314addf46908f5e85b.jpg

 

At least the new had a metal impeller!!!

 

 

M@

[Masked Marauder]

Is that the original pump? I am a great advocate of changing the pump whilst you are doing the timing belt anyway, especially so in timing belt driven pumps.

 

Lets face it, they are never going to be life-time items, so for the sake of an extra

[MatTdi]

I think it was the orignal pump, it looks like its done 90k :(

 

I have always changed waterpump on all the other cars, but the last belt change was done as the car was bought so did not have the chance to ask....

 

M@

[Danny Boy]

Yeah at last....got water pumped changed. exactly the same problem as u MatTdi.

 

cost

[Guest vr6galaxy]

Glad to hear your all sorted now Danny :unsure: at least the sleepless nights wont be you worrying over the car now B)

[Topbloke]

Don't like to say it but " told you so " :unsure: B) :unsure: B)