Technical Changing the headgasket on 1.2 8v

[Spookyb329]

Have a 53 reg Punto with mayo in the cap, gurgling in the heater matrix, and evidence of coolant seeping from the head gasket. If I bleed the system behind the engine near the heater matrix, then bleed again 5 minutes later, I get more air...I assume this is due to the gasket allowing air into the coolant circuit which then collects at the matrix?

Anyway, cheapest quote I've had is £280 including cambelt, but to be honest I want to give it a go myself, I could never have attempted a job like this on my (now sold) mk.3 Mondeo so might as well have a go whilst we have a relatively simple car

I've read the guide (Sorry, can't post a link to it as I haven't made 5 posts yet...:bang but its a bit vague in some areas, such as correct bolt tightening sequence and actual torque values rather than what appear to be a guess Also, I was under the impression I needed to rotate crank to top dead centre and mark the belt before removal blah blah, but from the guide it appears this isn't the case and the belt remains in situ?

I was also told I should get the head skimmed regardless, but now I'm wondering if the leak is just down to a knackered gasket rather than overheating seeing as the guide states that the gasket is meant to be a 2yr/24k serviceable part. Car runs fine. It leaks from the left and right front edges of the gasket. Its done 60k with little in the way of service history so I don't know how its been treated. Except the dealer claimed to have done a full service when we bought it a few months ago but the air filter is pretty clogged so I don't trust him

Thanks for any help.

 

[fingers99]

Get it skimmed. Will only cost about £30 and is a guarantee that your head is straight and clean.

I don't know that guide (or who wrote it) but the cylinder head gasket isn't a service item. Head Gaskets go for a reason -- usually overheating due to a stuck shut thermostat, low coolant levels (leaks!, improper bleeding, etc.).

Often it's worthwhile to get two guides, in which case the Mk1 Punto Haynes is downloadeable from rapidshare for nowt (Google will find it).

It'd be worthwhile fitting new belt and tensioner, water pump, cutting in the valves, re-setting the valve clearances and fitting new valve stem oil seals (they'll be included with the HG kit).

 

[Spookyb329]

Thanks fingers...I've just realised why the guide appears so simple...its the cam cover gasket rather than the headgasket Found a headgasket guide for the Cinquecento which apparently has the same engine, looks much more like what I'm looking for

cutting in the valves, re-setting the valve clearances and fitting new valve stem oil seals I assume all that involves specialist tools, and that a garage wouldn't include this in their quote unless specifically asked for?

The coolant appears to be seeping from the cam cover, I assume this wouldn't be the cause of the gurgling heater matrix and mayo in the oil cap? Would that definitely be the headgasket?

 

[rallycinq]

If you have coolant coming from the cam cover you have bigger problems than just a head gasket.

I would advise getting the head off and having your local engineering shop not only skim it, but pressure test and do the valves/shims.

A good machine shop will do this all properly and you can be sure that everything is OK.

It is completely unlikely that the garage quote incudes this level of care.

Cheers

SPD

 

[Spookyb329]

It may be oil, I just assumed it was coolant. Thinking about it I'm certain its oil, wiped it off and it was black, at the time I assumed it was just built up grime.

How much extra would I expect to pay to get the head pressure tested and valves/shims? Would I be expected to supply the valves/shims?

 

[beau]

i have done many punto head gaskets, if its not over heated then you dont need to skim it, just wasting money- as long as it looks ok anyway.

iv never touched the valves when changing the gasket either, no need to in the slightest imo.

tbh if you just took the head off, put on a head gasket, new exhaust manifold gasket & rocker cover gasket & new cambelt, it would be fine, thats what i would do, be cheap too, done many like this and all been fine.

 

[fingers99]

Frankly I'm gobsmacked by that.

Rather than waste time responding, I'd just point out that any decent engine shop will cut the valves for you and do the shimming. Cutting the valves doesn't usually require more than a tub of grinding paste and a swizzle stick (less than a tenner from your local factor), the shimming requires a set of metric feeler guages, a cheap digital caliper (maybe £15 the pair) and a calculator (you'll have one). Fluffy does shims at around £3 a hit, but you're unlikely to need more than a couple (they can be swapped around). Guy Croft does the special tool for the valve guide oil seals at £50, but you can use a suitable socket (as in the Haynes) to pop them on.

Done right, you'll have a head which is at least as good as new. Save money(?) and you may end up with a bent head, lots of tappet noise and poor compression and poor peerformance.

The choice is yours....................

 

[Spookyb329]

Thanks both, have found a localish machine shop so have emailed them for a quote. They do full head rebuilds etc so might be a tad more expensive than a normal shop but we'll see. Got digi calipers so might invest in a set of feeler gauges along with the torque wrench.