Mk3 1.05 AAU

After putting it off, my car will not start anymore and I need to chnge the head gasket. Never done this before and am nervous. However, I can't afford a garage to do it so if it all goes wrong i'll probably scrap the car.

I've heard that I might need to get the head skimmed. I assume I'd have to disassemble the camshaft assembly for that but in haynes it says i'll need to use shorter valve stems or something. This looks like getting expensive. I'm sure a garage wouldn't go to all this trouble for the price i've been quoted (£400 including changing the cambelt and water pump) so how likely is the head to be warped? I don't think there's been any major overheating, and to be honest, all though I want to keep the car (the wife wants me to get rid) i'm not sure all this is within my capability. Any advice?

Chuck

Also - iv'e got one of those torque wrenches with an extra thin bar and a plastic guafe across the handle end, which bend to show the torque. Good enough?

Edited 21 June, 200719 yr by Chuck Yoghurt

If there hasn't been any overheating you should get away without skimming the head. I didn't skim my head when I changed the head gasket. It only took me and my dad an hour and a half as well, and neither of us had pulled the head off a Polo before, but have done a head gasket before.

You're supposed to use new head bolts as well. Why does your wife want rid? With the head gasket done the Polo would be more reliable than any modern shitheap...

Its not a bad job to do if you have some knowledge. Removal is simple, disconnect anything that is attatched to the head, installation, vice verca tighten bolts from middle out 40nm, 60nm then 2x 90 degrees.Pay no attention to the haynes manual if you do need the head skimming you can leave the valves in.

What makes you think the head gasket has blown?

Has it been to a garage to be diagnosed.

GOOD LUCK

if it never overheated then i wouldnt bother skimming it (flame me all you want guys) i didnt on the last 2 polos i changed gaskets on (gt and g40)

i have used same bolts before as they dont stretch but if your keeping the car, buy some new ones (about £15)

other than that you'l need a new gasket, some oil, a filter, some coolant and some water, a splined tool to remove/refit the headbolts, a torque wrench (and an angle tightener or a good eye for angles) may as well change the water pump and the cambelt if needed. (this will need... an allen key bit set type thingy just as you will to get inlet manifold off).. and of course some sockets &extension bars of various sizes. could probably do with new inlet and exhaust gaskets too

::: coz_g40 says 2x 90degrees... this is wrong, its 2x 45degrees or 1x 90degrees per bolt as the final stage :::

it'l probably cost you over a hundred in bits and tools, but worth it for the experience i guess.

Edited 17 June, 200719 yr by rae

The bolts *do* stretch and in an ideal world should be replaced, you can get away without replacing them but to say they don't stretch is just wrong. Otherwise, rae's advise is spot-on.

... what i meant was.... they aren't "stretch bolts" that stretch on purpose when you torque them up properly

... what i meant was.... they aren't "stretch bolts" that stretch on purpose when you torque them up properly

they are. aparently.

Its not a bad job to do if you have some knowledge. Removal is simple, disconnect anything that is attatched to the head, installation, vice verca tighten bolts from middle out 40nm, 60nm then 2x 90 degrees.Pay no attention to the haynes manual if you do need the head skimming you can leave the valves in.

What makes you think the head gasket has blown?

Has it been to a garage to be diagnosed.

GOOD LUCK

Yeah, i'm sure it's the HG that's screwed because of pressurised coolant system, water from tailpipe. Now it won't start, although it 'wants to' I think there's water in the pots.

Do you mean that if it needs skimming, it can be done with the valve gear and cam in place?

I've got one of these torque wrenches;

Will it be accurate enough, do you think?

I will replace the bolts just in case. The thought of putting it back together and having to re-strip it again gives me the cold-sweat!

How hard is it to get the timing right when I re-asemble?

What is an angle tightener? Will I be able to make one with a disc of card with the angle marked on it (or something)?

Thanks everyone.

Chuck

Edited 18 June, 200719 yr by Chuck Yoghurt

Yeah just leave the cam etc alone if it needs skimming but for the sake of about £30 + vat you may as well get it done.

That torque wrench should be fine.

Ignore Rae's torque settings, I'm a german car specialist and have been working on these for years.

As for the timing belt, line mark on the crank pulley (the "0")with mark on the belt cover (top of pulley) and the dot on the cam pulley with the arrow on the cover (bottom of pulley) turn the water pump clokwise to tighten. New water pump is highly recomende!! Could just mark the belt and pulleys with tipex but its a bit rough.

Keep us posted if your struggling let me know and ill try and help.

Keep us posted if your struggling let me know and ill try and help.

That is most kind of you!

I will start to begin to commence the operation this evening!

Chuck

... what i meant was.... they aren't "stretch bolts" that stretch on purpose when you torque them up properly

No they are stretch bolts which stretch on purpose.

Just read something that chilled me right through!!!

Do cylinder head bolts have a habit of snapping when you torque them up?

Has anybody had this dire experience?

If it happens, how the f;;k do you deal with it?

Also, regarding the headbolts:- are they torx or splines, and what size are they?

Chuck

Edited 18 June, 200719 yr by Chuck Yoghurt

... what i meant was.... they aren't "stretch bolts" that stretch on purpose when you torque them up properly

No they are stretch bolts which stretch on purpose.

Hope this helps. The bolts are not stretch bolts. They RARELYsnap as long as you clean all the bolt holes out and put o bit of copper grease on the end of the bolts.

DONT PANIC!!

Edited 18 June, 200719 yr by coz_g40

they are not "stretch bolts" on mk3 polos.

and re the tightening:

180degrees .. or 2x 90 ? no chance, its hard enough to do it 2x45 - or 1x 90 let alone go 180degrees.

if thats your attitude forget it!

oh, and if your such a specialist... why the post about injectors? that says to me you know naff all... ( http://www.clubpolo.co.uk/forum/index.php?...st&p=663022 )

Edited 18 June, 200719 yr by rae

they are not "stretch bolts" on mk3 polos.

and re the tightening:

180degrees .. or 2x 90 ? no chance, its hard enough to do it 2x45 - or 1x 90 let alone go 180degrees.

if thats your attitude forget it!

oh, and if your such a specialist... why the post about injectors? that says to me you know naff all... ( http://www.clubpolo.co.uk/forum/index.php?...st&p=663022 )

Listen mate,

I realise you feel aggrieved, but I just need help changing the HG on my car! Don't get shirty, instead, tell me how to get the fucking crown nut off the end of the camshaft. I tried jamming a spanner between the cam-wheel and the engine mount, with a length of scaffolding on the end of the wrench. All that happened was the engine wobbled up and down, the spanner bent and then got jammed behind the cam-wheel and I had to saw it in half with a fucking hacksaw to get it out. Not before gouging a load of metal out of the cam-wheel though, probably bent the fucking thing and knowing my luck most likely the camshaft as well. FUCKING HELL! You think you've got problems? I will prevail! Just give me encouragement guys?

The Haynes manual tells you how you can make a sprocket holding tool on page 2A-5. Or you can buy one but i am unsure as to how expensive they are.

The camshaft wont bend, they crack or chip so you can easly tell if they get messed up. However the sprocket is a different matter if it is in a bad way then you will want to replace it becuase its not good to have it unbalanced whilst running.

Dan

if thats your attitude forget it!

Don't get shirty,

wasnt a dig at you... lol

to get that end nut off the camshaft, and i know it isnt the safest way,... keys out of ignition, car in 1st gear, handbrake on tight, breaker bar or long torque wrench on a decent socket on the cam bolt...... lift..... tug it upwards and it'l come loose eventually... yes the engine will rock a fair bit...

just dont tell me you've been tightening not loosening it!!! :p

just dont tell me you've been tightening not loosening it!!! :p

ha ha very funny. I hope i've attached a pic of the cam-sprocket. you can see the damage on the bottom edga. Also slightly rounded that nut that hols the cambelt cover on. woe is me. think I need a new spreocket?

Chuck

errm oops. iv never tried doing it with the belt off...

if it spins round now youl hit the pistons with a valve or two....

if it were me - i'd put the belt back on ---where it was--- (ie timed up) and keep it tight until youve losened the nut!

best off using http://www.rotamag.co.uk/shop/images/sockets.jpg impact wrench sockets (as in they only have 6 sides) not the multi purpose sockets (that have grooves in them, like for a 12 sided nut - forgotten real name!)

errm oops. iv never tried doing it with the belt off...

I know, i know. Some 'helpful' urchin who thinks he knows about motors slipped it off while my back was turned. Little bastard. Wish I had a driveway. Help like that I don't need! First job this evening is to refit the belt - waste of bloody time. In order to do this I need to loosen the water pump - correct?

Using your method is there not a danger of the belt slipping or snapping, as it would be the only thing bracing the sprocket? If that little idiot costs me a set of valves i'm gonna try some amateur rectal surgery with a jack handle!

errm oops. iv never tried doing it with the belt off...

I know, i know. Some 'helpful' urchin who thinks he knows about motors slipped it off while my back was turned. Little bastard. Wish I had a driveway. Help like that I don't need! First job this evening is to refit the belt - waste of bloody time. In order to do this I need to loosen the water pump - correct?

Using your method is there not a danger of the belt slipping or snapping, as it would be the only thing bracing the sprocket? If that little idiot costs me a set of valves i'm gonna try some amateur rectal surgery with a jack handle!

sometimes you can just about slide the belt back on without loosening the water pump... not very reassuring that its tight enough but it does work. just be sure to put it back on where it was!

if youv knackered up the cam sprocket you'll need another one anyway, so why not jam a thick metal bar onto it somehow... such as your jack handle!

the belt wont snap - it isnt "that" much force... and it shouldn't take much of an attempt to get the bolt off with something holding the sprocket still like the belt. worst that can happen is the force turns the engine... big whoop its timed up right so no damage will be done

if you snap the belt or it jumps a few notches... thats a different story.

if in doubt, put the belt back on, tighten it up with the water pump, and undo the sprocket nut.

All the time I was struggling with the bolt, the belt was on thank god! The only movement that might have happened afterwards was through the previously mention idiot turning the sprocket by hand. Please tell me that won't be enough to bend the valves? If it has then I only need the valves right, not all the springs and other shit?

Why are you trying to take the camshaft sprocket off? You dont need to. Just remove the camshaft,sprocket,inner plastic housing and oil seal as one unit. Make life easy man,address the stress. Or just take the head off with it all attached,if you're not skimming the head. And leave the exhaust manifold on aswell,unless you like cans of worms.

All the time I was struggling with the bolt, the belt was on thank god! The only movement that might have happened afterwards was through the previously mention idiot turning the sprocket by hand. Please tell me that won't be enough to bend the valves? If it has then I only need the valves right, not all the springs and other shit?

depends how far it's been turned...

in all honest, i'd leave it if its being such a pain, and remove the water pump screws, and the whole black thing comes off.. just one other bolt in the middle of it (see attached)

water pump = 3x bolts - numbers 9 on diagram

black plastic thing retaining bolt = number 12 (cant rememebr if this screws into head or block... if its the head dont bother removing it for now

plastic thing will be stuck to head then.. at least youl get the head off and if you dont turn anything like the sprocket any more, you cant do any damage to the valves if none has been done already... because youl just be lifting the head off as it is now.

this isnt the best way of doing things but at least youl get the head off. you could always remove screw 6 and the plastic thing will spin around so you can move it out of the way

Edited 19 June, 200719 yr by rae

You dont even need to take it off - just lift the head a few inches,that plastic shield will bend okay and allow it to tilt far enough for you to remove the gasket,give the surfaces a clean,fit new gasket and drop head back down.