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So, how difficult are these head gaskets to change then?

G

GPF

New member
Well, I guess I'll be finding out!

Had a spot of bother on track yesterday and, to cut a long story short, no4 is now full of coolant. [&o]

I pulled no4 plug to check first because of the reputation no4 has and, sure enough, full of water. Steam vent kit will be going on next!!

Bugger. It was going so well too and passing pretty much everything else!

I'm pretty sure there is no rod/engine damage as it didn't fill the cylinder until after I shut it down - although it did start missing - and I'm assuming it is just the HG rather than cracked head but I'll see what there is when I get the head off.

Needless to say, there will probably be some stuff to upgrade while it's in bits. Big Valve head? One of those NA cams with the slight overlap maybe??[8D]

I was already thinking of refreshing the rings and bottom end soon. Does it make sense to do this at the same time?

To do it properly is it an engine out job? - in which case getting exhaust manifolds off to split the head will be easier once the engine is out of the car.

Then again, I'm not sure I fancy trying to get the engine out myself.

Can the rings and bearings be done just by dropping the sump? ("just" !!) In which case, is having the head off irrelevant anyway??

Any advice/things to bear in mind greatly appreciated.
 
Have only thus far dismantled mine following timing belt tensioner failure back in January....... dismantling was OK aside from struggling with damaged bolts that should have been replaced when the HG was last changed but no-one bothered. Used an awful lot of WD40 with overnight soaking to get a lot of the bolts out. Needed a few specific sockets especially a long 100-120mm hex socket to get through the cam box to the bolts securing the box to the head. Exhaust manifold simply leaned to one side to get the head itself off..... Spare pair of hands needed to lift off the cam box, otherwise you end up with hydraulic valve lifters all over the shop.

Been a few years since I have tried anything like this, but very satisfying to have at leaast got the head off - now I just need the time to rebuild the head itself and put it all back together......
 
In my opinion, doing the head gasket is a much nicer job than pulling the sump as it involves very little under the car. On an 8v car its easily doable on the drive in a day with beer breaks. The manifold can stay fitted to the head iirc, just undo the 6 bolts to the crossover pipe

The sump is a ball ache and means supporting the engine, dropping the wishbones, cross member, steering rack, cross over pipe and probably some other bits I forgot.
Its not that much more work to drop the engine but it depends how far you want to go refresh wise, lots of other jobs become a breeze with the engine out.
Unless its using oil I would leave the rings alone myself.

With the sump and the head off you can change the Con rod bearings and rings. The sump gasket can be a pain to get back in place also it is quite easy to strip the sump bolts, use a torque wrench.

Oh if its staying apart for a while, store the lifters in oil and make sure they are nice and pumped up before re-fitting.
 
ORIGINAL: JamesO

In my opinion, doing the head gasket is a much nicer job than pulling the sump as it involves very little under the car. On an 8v car its easily doable on the drive in a day with beer breaks. The manifold can stay fitted to the head iirc, just undo the 6 bolts to the crossover pipe
Click to expand...

Changing the HG is easy, rebuilding the bottom end is a lot more involved! I don't think its a while I'm in there case. My engine is nearly rebuilt now and I would not have wanted to do all that under the car! But then again I have replaced pretty much every replaceable component in the whole engine rather than just main bearings and rings..
 
I've not yet put a Turbo engine back together, but have stripped it down twice.

Taking the head off is actually straightforward - ISTR the most tricky bit was actually get the cam tower with lifters in situ off was tricky as they have a tendancy to fall out !

My best piece of advice = take photos of EVERY Step with a digital camera, that way when you come to put it back together again you can view them on a lap-top :)
 
Graham, I did exactly what you describe, cyl 4, bit of steam from the tailpipe, and a hunch somethings wrong.......

and the ambient temperature was a bit above the norm.....? if so me too.

I have the workshop CD and had not previously had the head off. I ordered all the gaskets (incl cometic HG) from Promax, and removed head and inspected the inners.
As everything was good, I reassembled, torqued etc and never any problem since. 1.2 bar limit.
The Victor Reinz HG was rotten and had distorted on Cyl 4.
Good luck
George
944t
 
Thanks for all the advice - all duly noted.

I'll get a head set ordered on Monday - just need to decide whether to go cometic or stick to widefire.

As for the rings & bottom end, I'd really like to get those done but don't want to bite off too much!

I think I'll just get the head off and look at the bores first, as if there is any scoring it will probably steer me down the engine out route anyway.

Oh, George, yes it was an unexpectedly hot and sunny day - plus I'd probably been hooning it round the track putting various exotica to the sword for one lap too many[8|]
 
Common fault with no 4 cylinder not getting enough coolant to the head (airpocket) the mod involves drilling and tapping a take off in the rear of the cylinder head and routing some pipework to the header tank, not done mine yet as everything is okay.
 
There is already a take off at the back of the head for the heater feed. Maybe easier to T into that but they are a pain to get near to and also remove when trying to get the head off.
Alasdair

 
Alasdair, the vent kit addresses an area of either poor flow which boils locally, or an airlock in the head casting. Therefore it has to be drilled and tapped into the head (and the head needs to be off).
The line then returns into the expansion tank.
I dont have this, but did study it. Its a good precaution IMO
George

944T
 
Finally found the tme to get the head off the other week - not a bad job at all really - even the exhaust manifold studs came out nicely!

Bores look OK so have decided to just do the HG rather than dropping the sump.

While the head's off, I've taken all the valves out and checked the guides etc. All are fine but I found that 1 of the valve stem seals was completely shot, one had completely come off the valve guide, and a few others were only just on them.

Doing a bit of seaching turned up comments that there are 2 types of guide - one with a lip or rib on top for the seal to grip, and one completely smooth that requires cement to bond the valve stem seals to.

Mine are smooth, and there is no sign of any cement or adhesive under the seals.

Is this "use an adhesive to bond the seals to the guide" correct, and if so any ideas what to use?

Regards

Graham
 
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