Porsche Enthusiasts Club Forum

Hey all,

New to the site (of course) since I'm considering buying a 928. Fella in the work is selling it - a 92J S4. Now it's got a blown head gasket, but apart from that(!) it seems pretty decent.

My research reveals a price of "from £1000" to do both gaskets up to £3.5k if it needs two replacement heads as well. I have a good independent man who should be able to do the work for me...

So - any thoughts on those prices? I agree it makes sense to do both head gaskets while it's all apart, and the timing belt/tensioners/water pump et al.

What's a rough value on the car? 92J 928 S4, 94k miles, paperwork up to 75k, new radiator/battery/front brake discs. Pretty good order, couple of minor rust bubbles on the filler cap and one door surround. Cheapo tyres, but still has original tonneau cover, toolkit, solid rubber spacesaver etc.
It's a sort of very dark browny-grey colour

Thanks in advance, of course, for any help you can offer...

Al

Hi

Value with head gaskets or heads gone really depends on condition of the rest.....

Personally I would offer him £500....or MAYBE JUST MAYBE £1000 if the rest was good.......

You cannot afford to offer more in case it needs a new engine...think many many thousands....

All the best Brett

Yup, I guess that was my thinking. The rest is fairly decent order, but as you say, I'd not want to risk spending an absolute fortune on it.

I've arranged to borrow it for a day and take it to my tame independent spannerman for a lowdown. If he gives the car (and the repair job) the nod, then I'll subtract his estimate from my personal 'fun car' budget and offer the vendor the difference.

Thanks for the advice.

Al

Worth a lot more in parts.

Not that they will sell at this price, but someone has an interior (seats and door cards) plus an exhaust cat for £700 on ebay.

It is a late S4 though and lowish miles. Would make a nice parts car if its been looked after??

Well I'm shocked to hear such a utilitarian approach being mooted on an 'enthusiast's forum'!!

You're right of course, and the seller is aware of this (he's spent a couple of months sourcing rad/brakes etc for it before he realised it had head troubles). All the specialists he spoke to said the same thing: worth good money as a breaker.

But there's no romance in breaking a car for bits - especially a 5l V8 supercar that's only a few days' spannering work away from running well. Much better to get it on the road for £4k and breeze about south London like a king - which is what I hope to do!

Update...

The seller has had some advice which suggests the problem may be down to a failed oil cooler (I believe there's an oil/water heat exchanger circuit in the rad?). This could explain the symptoms (losing coolant and water emulsion in the oil).

Does this sound possible/probable? A much easier fix than a head gasket gone of course if so. Any ideas how best to check it? My independent mechanic has already suggested a cooling system pressure check.

Cheers!

Al

Hi

Ask your mechanic to do a "Snap-On" block test....

Its a tube with some royal blue coloured fluid that inserts into the hole where you top up the water/antifreeze....

He uses a little rubber puffer to pull through some gases on top of water....NOT the water itself....

With engine hot....

If it detects COMBUSTION GASES it will turn YELLOW or GREEN...

The oil cooler/rad problem will NOT affect the block test so it WILL tell you which has gone...

So to summarise...IF the fluid goes green/yellow its heads or head gasket DEFINITELY !

NO colour change its probably oil/rad etc....

Ps. Any decent mechanic will have a snap-on block tester or you could buy one off the snap-on van for around £40...

I have one if you are near to me ???


All the best Brett

Yes the radiator has oil cooler at side, and weld can fail between oil and water cooler,

As well as Brett's suggestion (great tool - not heard of it before), another diagnostic is to disconnect oil lines to radiator, pressurize the oil cooler after emptying it, and see if you get any air bubbles in expansion tank.

If the car is overheating then head gasket failure is more likely cause.

Good stuff guys. I'd heard of using a Gunson CO meter in the past to 'sniff' the top of the rad cap hole for combusion gasses, but the Snap-On gizmo sounds even better. Pressurising the oil cooler is a smart one too.

I'm in Worcester Park/Kingston area, so not so handy for Bournemouth, sadly. But if my man doesn't have the block test doohickey, I'll get hold of one somehow.

Thanks again!

Al

Hi Al

Its a VERY good piece of kit...

The test I described is easy to do but it also does more complicated testing....

For example....lets say it fails the test ...i.e the blue fluid goes green (bad) or yellow (worse)

You could then remove 1 plug lead at a time and run engine for a few minutes without that lead attached.....then retest.....if the fluid now stays blue, you just found the cylinder with the problem or the cylinder with the head gasket blow nearest to it.....if you see what I mean....

It would mean 8 tests for our engines of course lol, but you only use a fixed amount of fluid up to a level mark (around an inch) and there is a fair amount in the bottle you get in the kit...

The newer type of kit will also do Diesels although its slightly more money....


Its worth buying this kit for anyone who even suspects a slight blow on a head or head gasket as its DEATHLY accurate....

Some sellers will say things like...its PROBABLY only the oil cooler/rad leaking when they may have already used this tester.....

Or they may genuinely be unaware of how easy it is to test...

Just found a link for the kit.....this is the GENUINE Snap-On one....

http://cgi.ebay.co.uk/snap-on-mac-Block ... 439764ed89

All the best Brett