[engine_work] Novice Attempt At Head Gasket Change

[Obey_R 23]

It doesn't look like it's been repaired to you then?

[feb 47]

Do heads always crack around the spark plug holes and why?

[Obey_R 23]

Well I got the block mating surface cleaned up today ready for when the new gasket goes on. Just quick going over with a wire brush followed by some 400grit. I lightly dusted over the tops of the liners, being very careful not to move them(!), as they had quite a build up of crap around the tops.

 

As for the head, I've got a bargain from Anthony (he doesn't know yet, though! ) for his partly reconditioned head.

 

 

On this picture you can see how the second cylinder has affected the colour of the manifold branch!

Edited July 9, 2011 by Obey_R

[Obey_R 23]

So after chatting to Anthony I need to check which tensioner setup I have. I've bought all the bits for the earlier, spring loaded type, but after looking at cambelt covers etc, I think I have the more recent, eccentric type.

 

 

Can someone please comfirm? If it is the later type, does this mean I have the 114 tooth belt (I will check when I take the old one off anyway). It would also mean I have the wrong waterpump fitted, wouldn't it? Again I have a new one but would need to swap this over if that's the case.

 

On a side note, I've just been cleaning the contacts on the start solenoid and the bloody thing has cracked and falled off, bugger! New starter now I think?

[Anthony 1,003]

Yup, that's a later 114 tooth belt and eccentric idler setup.

 

Waterpump should be like an Mi16 one were the casting forms part of the cambelt cover, whereas you've got the earlier style waterpump that doesn't have that casting. It's not the end of the world and still works, just means that there's a gap in the cambelt cover if you use the later cover that the engine is supposed to have.

[Obey_R 23]

Brilliant, thanks. Means I have to change all my cambelt kit over now! One problem after another with this bloody thing...

[Anthony 1,003]

Well, I'll apologise for suggesting that it would likely have had the spring tensioner setup - most do though!

 

The other option is to keep the belt and tensioner you've bought, and just pickup the few small extra bits needed to use the earlier style tensioner and belt - from memory, it's just a spring, the block/holder for the spring, the cam-shaped bit that slackens off the tensioner, and three nuts.

 

Probably easier just swapping the belt and tensioner for the later ones though, plus they're shared with the later 306/405 8v engines.

[Obey_R 23]

Brilliant, thanks. Means I have to change all my cambelt kit over now! One problem after another with this bloody thing... Started off as just a head gasket (took me £80 worth of parts changed before I even knew this) then thought I'd do waterpump cambelt tensioner etc, off with the head and that's cracked so need a new one of those. Now the waterpump etc has to go back to get changed and I need a new starter!

 

Ooops, hit enter too early.

 

It's not a problem returning any of the bits as I work in a motorfactor, I think the newer steup is cheaper from when I was pricing it all up, besides, I've got to fit all the head etc back before I start doing the cambelt and everything anyway!

Edited July 12, 2011 by Obey_R

[Anthony 1,003]

The joy of 20 year old French cars!

 

Atleast you know that it'll all be good and should (ha ha) last once you're done

[Obey_R 23]

That's what I thought when I bought a wreck covered in rust. Oh well, I thought, at least when all the welding is done I know I will have a good shell with a good engine...

[DamirGTI 342]

Do heads always crack around the spark plug holes and why?

 

Cos these spots are the most heat stressed on entire head/combustion chamber - exhaust valve seat as particular (and throat , the area just beneath the seat or above in the chamber , as on the Obey_R's pic ..) exhaust valve , area around spark plug hole (plug adjacent/indexed towards , closes to the exhaust valve rather than inlet or middle of the chamber ..) ...

 

It's mostly the exhaust valve seats which do the lions job of cooling the valve the milliseconds as it contacts the valve seating surface and transferring hot combustion gases into the manifold .

The temperatures in the coolant passages inside the head are extremely high around the exh. valve seats in-between the ex. seats and spark plug holes , they have much more going against them (heat from combustion process , hot exhaust gases , heat from exhaust manifold , poor air circulation outside of the head if placed exhaust side backwards to the engine bay ..) than the inlet side of the valve train ...

If exh. valve guides are sloppy , if the exh. valve seat is worn hot combustion gases will soon erode the seat/valve and then when that's done the damage , burns/cracks are to be expected ... also , most important .. if the coolant system isn't up to the job , if its un-efficient , if it cant hold system pressurized to prevent coolant boiling , if it isn't properly bled out of air bubbles etc. - localized boiling will occur creating steam pockets which will in the end lead to thermal stress and metal cracking ...

 

.. sorry for hijack boys , carry on

 

Damir

[Obey_R 23]

Ok so got the new head from Anthony today, very happy. Took it to get skimmed this afternoon, brought it home and put new valve stem seals in, oiled up the valves and popped those back in place, along with springs and tappets etc. Bolted the camshaft down and then realised I don't have the tools to shim it myself!

 

I'll try and get hold of a decent micrometer, but what's the easiest way to turn the cam without it bolted up to anything? Just to check, I turn it so that the lobe is fully vertical, measure the bottom and continue to the next one. Then measure shims, fit new ones and recheck with the cam back on?

 

Failing all of that, how much would it normally cost to send just the head to a specialist to get done?

 

Ross.

[Obey_R 23]

So I got all the shims measured up and clearances checked, only to be told to do it once the head is fully torqued down onto the head, so that will have to wait a bit.

 

Tried to fit the head back on today, got all the surafaces prepped, engine mount off etc and ECP have sent the wrong headgasket, so that will also have to wait!

 

So whilst I was doing that a bloke came and delivered my new starter motor from AlastairH (thanks!) so at least I could do something today! That's all fitted up with connections cleaned, it is the newer slim bodied type so hopefully will get rid of my clicky starter syndrome!

 

So now I have to wait for the new gasket to arrive, get the head torqued down and re-check all the valve clearances/adjust as nessaccary. I can then work at getting the crank pulley off without worrying about disturbing the liners, get the tensioner and waterpump swapped over and fit the new cambelt!

 

I sent my injectors off to InjectorTune on wednesday last week but I've not had them back yet, as soon as I do that should be the last peice of my puzzle!!

[Obey_R 23]

Oh and I'm still waiting on the new vac advance from the USA to be delivered.

[Obey_R 23]

Right so I've got the head on and torqued up, mount back on etc.

 

 

So next job was to remove the crankshaft pulley, which took a bloody age! Loads of plusgas and a bit of tapping with a rubber mallet soon (an hour) got it off. I then found what was left of my cambelt cover, or rather, the only peice that the last owner thought to put back on.

 

 

Waterpump and tensioner were then taken off and the mating surface cleaned up ready for the new one to go on. I used the gasket that came with the waterpump with a smear of red instant gasket to seal it up. Tensioner was then just nipped into place ready for fitting the belt.

 

 

So now I'm waiting on the correct size shims so I can do those, and in turn get the cambelt on without worrying about taking it off again. As we speak the inlet manifold is soaking in degreaser to get rid of all the black s*it inside it. Once the cambelt is on it's then just a case of putting it all back together!

 

Oh and I'm still waiting on the vac. advance from the USA

 

PS. I ordered a cambelt cover set from Pug, all of it arrived apart from the top plastic peice, but I can get that on here without a problem. So the other two peices and various bolts/screws cae to £54! Expensive, but I'd rather have it there for peice of mind.

Edited July 22, 2011 by Obey_R

[Miles 331 1 Cars]

Silly question, But what engine is it? as the Blocks a late 'Z' type with the top of the block being like that and the tensioner

[Obey_R 23]

As at as I'm aware its a standard 1.6 GTI on a J, 1992. Does it look like it could be something different?

[Miles 331 1 Cars]

yes, as said the block is a CAT type block which a 1.6 never used along with the tensioner, has it got the engine number and type on the tap by the front engine mount?

 

But it's got the 1.6 pistons so it could of been a block change due to a rod sticking out of it or cracking which they do

[Obey_R 23]

It says... B6E 031027

[Miles 331 1 Cars]

Is that stamped into the block or on a tag?

[Obey_R 23]

That was stamped on the block, I assume by 'tag' you mean litteraly a thing hanging with writing on it? No it was engraved into the block near the o/s mount. Is it not what you expected?

[johno_78 2]

Where did you get the work done on the head? I've just moved to the area and am looking for some recommendations.

[Obey_R 23]

Pauls Engineering I think it was called, in Swaffham