The Mitsubishi Pajero Owners Club®

2.25diesel

I have a copy of the Mitsubishi manual for the 4D56 engine.

That manual lists a sealant to use with the half-moon seals, but not the rocker cover gasket itself. Are you meant to use sealant with that gasket, or simply install it with a thin smear of oil?

I am fairly sure that the breather needs to be cleaned out, so thought that I may as well adjust the valve clearances at the same time.

The manual says that after adjusting the valve clearances, the engine should be warmed up and tested. If they need to be re-adjusted, obviously this would mean removing the cover again, which would be a pain once the sealant had set.

I have also read on here that some engines have ended up running worse after the valves have been adjusted, with some saying they are best left as they are if the engine is running alright.

The manual also says that some engines have what the manual calls "elephant foot" type adjusting screws which can be difficult to measure the clearances with a feeler gauge. Were these used on the engines fitted the Mk1? The manual I have is listed as being for engines from 1994 onwards.

Also, what would be the best way of keeping any foreign matter out of the rocker area while the cover was off? from what have read on here I may need to soak the breather mesh in solvent for a few days to soften up any sludge in there. Obviously the engine won't be running while the cover is off.

Thanks for any replies.

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emax · Posted: Wed May 30, 2018 0:25 Post subject:

Hello.
Just use the sealant on the half moons. A touch of oil on the gasket would be ok. Do not over tighten the rocker cover

I do not know about the valves.

Clean the gauze with some petrol, takes a few minutes. Put a cloth over it while you are doing it to stop anything dropping in there.

icehawk · Posted: Wed May 30, 2018 0:40 Post subject:

or as the saying goes,if it aint broke ,dont fix it.

2.25diesel · Posted: Mon Jun 04, 2018 22:22 Post subject:

I removed the cover and gave it a good clean up. I placed it seal side down on some cardboard first and cleaned off as much crud as I could from the outside using degreaser and rags. I used a fine steel brush to remove the worst of the corrosion. While doing this I tried to avoid getting any dirt from the outside into the under side of the cover.

Once the outside was cleaned I then put it in a clean bucket and did the inside using fresh degreaser and a clean paint brush. As I used water rinsable degreaser I then rinsed everything off with a hose and left it to dry in direct sunlight for a few hours.

When this step was complete I used brake cleaner and compressed air to clean out behind the breather.

It actually looks better than the photos show. if anyone else searches for it in the future, the second photo shows the breather cover on the underside.

2.25diesel · Posted: Mon Jun 04, 2018 22:25 Post subject:

As for the half-moon seals, the gasket was supplied with two. I found that there was only one at the very back of the head. The manual also showed just one. Why was the gasket supplied with two?

icehawk · Posted: Tue Jun 05, 2018 9:09 Post subject:

The 2.8 has two but is a different gasket,they might just send two out to cover both 2,8 gaskets.

icehawk · Posted: Tue Jun 05, 2018 9:11 Post subject:

That should have read 2,8/2.5,the 2.8 as a front half moon seal that's smaller if memory serves.

2.25diesel · Posted: Mon Dec 17, 2018 21:24 Post subject:

After being fine for six months and over 5000km covered, the gasket has suddenly started to leak again from the rear half moon.

Maybe the silicone sealant I used wasn't good enough quality.

2.25diesel · Posted: Mon Dec 17, 2018 22:11 Post subject:

I forgot to add that I am considering trying Hylomar non-setting sealant for replacing the seal again.

Has anyone here used it for valve covers?

Mark3 · Posted: Tue Dec 18, 2018 13:07 Post subject:

Any automotive silicon (instant gasket) should be fine, sit the half moon/s into it and put a bead across the top of them as well and the rest of the seal should be dry.

2.25diesel · Posted: Wed Dec 19, 2018 23:21 Post subject:

Thanks for the reply. I had some spare time earlier today so I cleaned the area as well as I could with degreaser to be certain that is where the leak is coming from.

When I refitted the cover earlier in the year, I followed the instructions from an official Mitsubishi workshop manual that I got from someone on here.

I put a bead of RTV silicone across both the top and bottom sides of the half moon as the manual shows.

The cover was completely cleaned and degreased, the rest of the seal was left dry. This was also done on a completely cool engine which was not started again until the next day.

I even tightened the bolts to the torque setting in the manual. I tried to do everything as it should be done and yet it still leaks.