Thread: Head gasket DIY replacement

Before you replace a head gasket, use a torch and a small mirror to inspect both ends of the cylinder head-to block join. This is where minor coolant leaks often occur. Then remove all your spark plugs and check for funny coloured plugs and ones with rust on them. Diagnosis will help you pinpoint your area of problems.

As for instructions, purchase a "RAVE" CD workshop manual from the "shop" tag above.

Dave's Interesting Things - RRMAN86-94

Nothing really complicated, just undo the manifold one section at at a time, use well fitting 6 point sockets on the head bolts, and do them up with a torque qrench in the approved order and tightness steps.

The steps are basically the same as the P38 albeit there are more electrical bits and pieces on the P38.
I recently did my 96/97 P38 with the Gems engine and it was more similar to the older motors then the Thor engine steps that are detailed by Paul.
Nevertheless, its not very hard to work out what needs to be pulled out as you proceed along and using Paul's reference as a guide.
Good luck with the process and hope you loosen the exhaust manifold bolts without too much drama.
A good long breaker bar is a very worthwhile investment.

You need to get hold of an early edition of RAVE which is several hundred pages in searchable pdf format of detailed workshop manual etc. with step by step instructions.

Do a google search to download. EDIT ---yep ,get one from Dave!!!

Take plenty of photos as you go and use plastic bags with index card to 'bag and tag' all the bits, nuts, screws etc.

Composite head gaskets are the go. If you're going to keep the vehicle I'd suggest investing in head studs vs the stretch bolts normally used...

You need a VRS (valve regrind set) gasket set. Payen or Elring are reputable brands. Also, you'll need some Loctite 518 and RTV sealant etc

Above all, do a LOT of reading up before you begin and make a list of stuff you'll need. Take your time and ask questions here. There are many wise and knowledgeable folk ready to share their 'learnings'

Do a search on here ..there are lots of hints re. this job. It's a big task but a satisfying one ... mind you, a simple head gasket can become an extensive/expensive rebuild (new timing chain/rockers/rocker shaft/lifters/camshaft/oil pump/water pump...)

If this is the first time this has been done and the vehicle has a good number of km on the clock, then probably all of the above will need replacing...

cheers

G`day John ,

i`d suggest you try cleaning the stepper and see if the idle settles .

Also , one of our`s had been loosing coolant for awhile with no signs of pressure or overheat nor liquid on the ground , first hot day with the air on going to town the temp came up , checked coolant level and was correct .

Got back home swapped the radiator and found from the condition of the radiator where the coolant loss had occured .

This was two months ago , with this radiator it losses no coolant and the gauge stays central , as it did .

May not be yours but was mine and if you buy some of the bits suggested here if you need to do the gaskets you`ll be dissapointed as yours wears tin gaskets and has 14 bolt heads which have reusable bolts ETC .

Hi PLR,

Thanks for the info. I cleaned the stepper motor but it didn't seem to have any effect. Of course the steeper motor could have had it. Had a mechanic put the engine on his magic diagnostic box and there were/are no messages from any of the sensors showing errors. This and the fact that he found gunk in the breather system (the bit that sits at the front on top of the right side rocker cover and connected to the plenum) he said means it's a head gasket leak.

Regards,
John

Originally Posted by JWM

Hi PLR,

Thanks for the info. I cleaned the stepper motor but it didn't seem to have any effect. Of course the steeper motor could have had it. Had a mechanic put the engine on his magic diagnostic box and there were/are no messages from any of the sensors showing errors. This and the fact that he found gunk in the breather system (the bit that sits at the front on top of the right side rocker cover and connected to the plenum) he said means it's a head gasket leak.

Regards,
John

G`day John ,

he could be right so long as it doesn`t just do alot of short trips because that can give the same and because of what it is the magic box and the engine computer won`t have much to converse about so the outcome is pretty much expected .

The spark plugs should tell if it has an internal leak .