DIY head gasket

[Javelin]

The head gasket blew just before Christmas and the van has been sitting there waiting for me to pluck up the courage to get the job done.

So, having run out of excuses I started yesterday.

So far,
Front seats removed, (a lot easier than I had thought)
Central gantry for handbrake/gear selector removed
Exhaust dropped down, turbo moved out and Exhaust manifold removed.

Will look at how to navigate my way through all the stuff on the Inlet side tomorrow.

I note that the cyl head bolts will need a special socket head, any ideas where I can get one.
Any ideas on other specific tools I'll need ?
or indeed any suggestions, things to look out for would be appreciated.

The last head Gasket change I did was 24 years ago on a Triumph GT6 !!

[Dave.]

Hehe old GT6 awsome cars i had a mk1 plus rotaflex rear end loved it ,

Anyway the socket is a multi point normal socket:) not the 6 flat side one .14mm i think

No need to remove the pump just the pipes and the inlet manifold .

You will need a big 38mm (i think) for the crank pulley to align the timing marks (the diesel pump drives the camshaft via a small cambelt )

There are lots of head bolts and some hide under the injector rail (easily missed)

Also on removal of the rocker cover there is a section on the camshaft for you to use a large spanner to hold it whilst you undo the cam pulley nut .

I cant stress this enuff .................GET THE HEAD TESTED FULLY FOR CRACKS ..i rarely do this with other vehicles but on the bongo WL engine it is an 100% must do

I had to have a new engine as it was cheaper than a new head !

i got a low miles complete lump for £450 it was also an easier job to fit it

Oh and your best changing the head bolts as they are "strech bolts" you can measure them after removal the exact measurments that are ok i cannot remember .

[francophile1947]

Best to use a genuine Mazda head gasket as well - there have been problems with the cheap Chinese gaskets and heads.

[321Away]

yes he's right its a 14mm multi point socket.
Julian

[Javelin]

Thanks for the suggestions thus far

Any ideas who I should use to get the head tested?
Any ideas on cost and/or suitable companies that can do it out here in the far east. (Suffolk)
Presumably I get it skimmed after it's been tested.

I guess it also makes sense to change the cam belt whilst I'm at it, are there any other jobs I should think about doing, assuming the head test comes out good.

[David Edwards]

I hope your bolts come out better than mine did, three snapped so I would order a spare set...good idea anyway, great what you have done so far, best of luck with the rest.

[Doone]

Any ideas who I should use to get the head tested?
Any ideas on cost and/or suitable companies that can do it out here in the far east. (Suffolk)
Presumably I get it skimmed after it's been tested.

Your local garage in Suffolk may be able to test for you.

[HeskinBongo]

Keep us posted of your progress

[Javelin]

Well after a week or two's delay I started on the engine again.
So sure was I that the head gasket had gone (due to some over heating issues we had before Christmas) that I didn't bother to check the cam belt until now and guess what ?

Hmm, bet you're gonna tell me this is an interference engine and I have to have the head off anyway as I'll of bent all my valves.

My other worry is now that the belt is bust I wont have any timing marks to set it all up again.
How much of a pain is it to time up ?

[HeskinBongo]

Hi there are timing marks on both the cam pulley 12.00 o clock on casing and about 9.00 o clock on the pump pulley

[Javelin]

Another delay but got cracking and got the head off.
Managed to remove it without snapping a head bolt which was a relief although I realise I'll need to fit new ones anyway.

On removal of the rocker box my heart sank as there were lots of "bits"
6 rockers had snapped.

However after removal there appears to be little if any damage to the pistons or indeed the valves.
I can see a slight valve mark on no 3 piston and maybe no2, which makes sense as these are the broken rockers but the mark is very slight and you do have to look hard.

I'll dissemble the head and get it pressure tested and skimmed.
I guess I should replace the valves where the rockers have broken.

Anyone got any additional thoughts ?

[HeskinBongo]

Hi very surprised the rockers failed

[sparkymik]

Very impressive effort and nice of you to share, I thought the timing belt was bad enough , have you got the Bongo on ramps?

Sparky

[Javelin]

She's actually sitting on the road outside my house (its rural and quiet round here)
I was going to move her into my yard but the delay in starting work has led to the brakes seizing up so I decided to start leaving her where she is.
So no, not on ramps. - er why?

Started to wash down the head.
The Inlet ports are fouled with black sticky, oily residue and its a messy business trying to clean it up.
Using diesel and a paint and toothbrush and I think I'm winning slowly.

One Valve is defiantly shot as when I fill each port with diesel you can see it oozing past the valve.
The others seem fine.

Noob question - When they pressure test a head, is everything removed?
In other words Should I strip the head of everything including valves, springs etc.

[Doone]

Noob question - When they pressure test a head, is everything removed?
In other words Should I strip the head of everything including valves, springs etc.

To get the head pressure tested, you can leave the valves and springs in place, but remove the cam and rockers.