Head Gasket.1.4 TDi need tips on how to do it please...

Losing about a cup of water a day and no visible signs of a leak and the header tank is overpressurising too so assume its a head gasket. Will be doing it myself so any tips on how to do it and overcome the tricky bits would be gratefully recieved. Particularly:

What are the head bolt torque settings? and are they stretch bolts that need replacing or can you just reuse the originals?

Where is the best place to get the head gasket/ head bolts?

With all the inlet and exhaust items on the back end of the engine what is the best way to get them off and get access to it all?

Whilst it is all off are there any improvements i can make? its a 75bhp model with a chip.

Thanks in advance...

I believe that they are stretch bolts. Can't help you with the rest because it is a job way beyond my limited knowledge.

Hi David,

You don't say what year your car is, nor is it on your profile, so I have provided some info based on my own car, 2002 TDi 75

The PDF should detail the removal and installation of the cylinder head.

Hope this helps

Cheers

Jeff

Jeff thanks so much for that PDF!
Really helpful, just read it all through.
I note the Part where they take the cam shaft pulley and carrier off, is that necessary? ( as it seems to need a special holder and puller) thoughts anyone?

Hi David,

Not 100% certain, but I suspect the reason the PDF shows the pulley and carrier removal is because the main objective of the document is to detail a swap of the head itself, therefore these ancillary components would be swapped to the new head, which would not be shipped with these items.

As you'll only be changing the head gasket, the strip-down of the head is not necessary, unless of course you find damage on the combustion chamber side of the head.
Depending on the mileage of the engine, and also if you plan on keeping the car for the long-haul, it might be worth a full head strip-down and refurb as the hard work would have been done in pulling the head off.

Please let us know how you get on.

Cheers

Jeff

hi David
Before you go to the trouble of removing the head, best to check if you losing coolant into the engine. It can only go three ways;
out of the system into the atmosphere, you may pick up signs of a leak where you park or check for dried coolant marks (pink if it's the Audi stuff) on the engine and surrounds. this is unless it leaks onto a hot component and evaporates.
into the combustion chamber which wil be evidenced by white smoke out of the exhaust whilst driving.
into the lubrication system, check under the oil filler cap on the tappet cover, not the fold-away cap, for signs of coolant mixing with the oil, a light brown muck.

also check in the cabin for signs of a leak from the heater matrix.
best test to do of course is a pressure test.

hope this helps, let us know how you get along.

blue skies
tony

Hi Tony
thanks for your sage advice, i have already looked at those possible exit points, it does seem to be a bit "wet" from the exhaust on tickover as well and the coolant tank looks quite pressurised and sometimes leaks out the top past the cap

Hi David, No you have to remove the camshaft sprocket whether you're changing the head or not. The sprocket won't fit through the hole in the backplate so you cannot get the head clear until its removed. I made this mistake and broke the plastic backplate as a result. You can buy a cheap puller off eBay for less than £15. Joe

Thanks for that advice Joe, these are the things that can catch us out, can just the pulley come off or does the backing plate have to come off as well? I have normal puller will that do it or is it a special one?

Update
changed just the headbolts on the assumption that the leak was slight and that retorquing the head would sort the problem out ( did the same on a Skoda VRS and it cured the pressurisation in the header tank) will see if it makes any difference, got to be tried for a £15 fix!

the torque regime is 40nm then 60nm then 90 degrees then another 90 degrees, did one bolt at a time in the correct order however upon unscrewing the bolt the 2x 90 degrees they were loose which makes me suspect that the bolts were not torqued correctly and they might loose some tension over time even taking into account some stretch past the elastic limit on the M12x1.5 thread pitch, anyone have any thoughts on this?

The usual start of headgasket problems is an overheat situation. This results in the cyl head casting expanding significantly more than normal which crushes the gasket sealing rings, leading to compression leaks. The low initial torque setting for the headbolts does little more than snug the gasket so as you may have effectively lost some gasket thickness its not surprising there is no residual torque left after backing off the 180 deg angle setting.

If the car has never overheated, just forget everything I have said.............

Cheers Spike

its a great theory and would explain why it would do that but it has never overheated in the 7 years i have had it so the actual cause is still a mystery, although i hope i have found a method to rectify partial leaks under load.

If anyone else is trying it, all i did was to change each head bolt for a new one, one at a time in the tightening order from 1 to 8 torquing to 60nm then 90 degrees and 90 degrees again. The difficult parts are the rear two rocker cover bolts which need a 1/4 drive socket set with a 10mm universal joint socket on and varying lengths of extension bars. The air intake tunnel which is fiddly and tight to get over the aircon pipes. Worst of all is the right rear bolt that requires the EGR valve to be removed as it fouls the EGR diaphragm ( AMF engines only and you might as well clean the valve out whilst you are at it as it will horrify you as to how gunged up it is ) and the back left bolt which fouls the wiper motor housing which needs to be removed ( and you might as well grease it whilst you have it out to prevent future wear and ensure as smooth action. Nice bits are the fact that the rocker cover has lovely captive nuts that you dont need to completely extract and can never get lost and which have self starting spiggots on the end that help locate them when you are putting it back.

Sorry for the delayed response David, not checked in for a while. No you don't have to remove the backplate once the camshaft hub is removed. The tool I bought was just a standard tool with a selection of bolts to screw into the hub. Cost £15 and worked fine. I can send you the eBay link if it's still on there.

This is the one I used.... http://www.ebay.co.uk/itm/CAMSHAFT-...s_Equipment&hash=item3362485433#ht_1482wt_989

Hi David did this resolve the problem? I have a similar issue I think pressureis building up and forcing water out of the overflow on the expansion tank you can see water under the nsf wheelarch after a long run. hope its an easy fix not sure if the waterpump can be tested? I think if the pump was desintergrated this would cause the water not to circulate and boil and probably push it out of the same overflow on the expansion tank. Any other ideas I dont fancy doing a new headgasket.

unfortunately not
but it was worth a try

poo looks like a new headgasket it is then. Oh well trip to the country where its a bit cheaper unless anyone know's a place in West London/ Surrey that are good and well priced.
Thanks