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Help on oil leak diagnosis
Posted: Sun Oct 25, 2015 6:32 pm
by lost2
Hi everybody !
It's been a long time since i browse this forum, most of the work needed on my l300 was regular and quite simple.
For long, there has been a tiny leak of oil in the back of the engine. Last spring, i decided to change the valve cover gasket for a second time since i own the truck, because i didn't put high temp silicone on the unfamous halfmoon part the first time. I hoped it would settle it... But it didn't.
My biggest fear seems to become a reality: the head gasket appears to leak. I cleaned the back of the engine in summer. Here is a picture i took today, after replacing the 2 ujoints on my front driveshaft ( since i was lying underneath, it wasn't much of an effort!)
Do you agree that it looks like a bad head gasket ? You can see in the upper part of the picture the blue half moon part of the valve cover gasket, with red silicone.

- image.jpeg (709.01 KiB) Viewed 4878 times
Edit: Sorry the pic was upside down. I turned it.
Thanks for your inputs,
Davy
Re: Help on oil leak diagnosis
Posted: Sun Oct 25, 2015 7:22 pm
by Growlerbearnz
I think you're right. The head and turbo high-pressure oil feed is at that end of the head gasket.
Re: Help on oil leak diagnosis
Posted: Mon Oct 26, 2015 4:45 am
by lost2
Thanks Growlerbearnz,
If I choose to replace the gasket (following Tojo thread will be quite helpful), what would you recommend to change, other than the gasket itself, knowing that I already changed (since I own the truck, less than 5 years/50 000km):
-timing belts and both pulley tensioners
-water pump
-water hoses
-Injection pump
Should I get a new valve cover gasket/halfmoon part ? A new manifold gasket ? Specific bolts (i.e crank bolt, head bolts, etc) ?
Other suggestions ?
I prefer to get all the parts I need before doing the job since it is my only car at the moment.
Re: Help on oil leak diagnosis
Posted: Mon Oct 26, 2015 6:56 am
by Lapprentis
Davy, try to find the post related to a metal half moon gasket to replace the usual rubber one. I think it will solved any potential leak in that area for a while...
Have you think about rocker and associated parts :
http://www.delica.ca/forum/viewtopic.ph ... r&start=15
Also check this post if you do not already have it:
http://www.delica.ca/forum/viewtopic.ph ... lit=rocker
Keep in touch
Lapprentis

Re: Help on oil leak diagnosis
Posted: Mon Oct 26, 2015 7:16 am
by lost2
Thanks Lapprentis for your answer,
The "Tojo thread" was the one I was referring in my previous post: its a nicely detailed diy head swap.
About rockers: on Tojo's thread (viewtopic.php?f=6&t=16587&hilit=rocker), he changes the whole head, so nothing is clear on how to do just the rockers. Is it simple to change/adjust the rockers? How many of these are there in total ? In the thread you showed me, Steven from Rising Sun, talks about rocker arms, adjustings screws, springs and shafts... do I need to change all these as a preventive work ?
Thanks,
Davy
Re: Help on oil leak diagnosis
Posted: Mon Oct 26, 2015 11:58 am
by Lapprentis
Davy, since I do not have any records on previous maintenance on my Van, I did order all the parts suggested by Steven (rocker arms, adjustings screws, springs and shafts); I will ask my mechanic to do that before my Delica will go wintersleeping. Yes, for me it is prehemptive as I want it to be healty from bumper to bumper
Lapprentis

Re: Help on oil leak diagnosis
Posted: Mon Oct 26, 2015 3:24 pm
by Growlerbearnz
New parts you'll definitely need are:
head gasket,
head bolts (MD040514 x18) They're officially single-use only, though Ive gotten away with reusing them.
Rocker cover seal (MD050312)
Half Moon seal- (the aluminium one is part number MD372348, plenty on ebay like so:
http://www.ebay.ca/itm/MITSUBISHI-OEM-1 ... 2a55eb8728)
I'd also replace the rocker bolt seals (MD000523) though they're easy to replace later without disturbing the rocker cover seal.
The manifold gasket (MR188679) is usually reusable, but have a look around the manifolds first- if you see signs of exhaust or oil leakage from the gasket, it might be safer to just fit a new one.
I wouldn't change anything else- your belts and tensioners should still be fine, and they can be changed easily without disturbing the head anyway.
When you're changing the head gasket, make sure to clean the head and block thoroughly, then, just before fitting the gasket, give them a wipe with a fast-drying solvent (like brake cleaner). You want the mating surfaces to be absolutely uncontaminated. It's probably a good idea to clean as much oil out of the head as possible too, just so it doesn't dribble onto the gasket when you're putting the head into place.
Re: Help on oil leak diagnosis
Posted: Mon Oct 26, 2015 7:03 pm
by lost2
Thanks Growlerbearnz & Lapprentis for your quick replies.
I have checked with local part store, and been able to order an overall upper head gasket kit (HS9084PT1), including head gasket, manifold gasket, valve cover gasket and bolt seals. I believe there is also a seal for the camshaft.
They will have the set early this morning, so I figured I better get started with dismantling everything tonight. I had forgotten about ordering new bolts: if they can have some before re-assembly, I'll buy new ones. If not, I will probably go with the old ones.
NEW PROBLEM !! I just had everything out of the way ( driver's seat, fan, radiator for better access , power steering pump, manifold, crank pulley, belt covers .... SURPRISE !!! The balance shaft belt is broken. Very similar to this thread :
http://www.delica.ca/forum/viewtopic.ph ... elt#p45462
Also the crankshaft seal is leaking. I will change it.
I made sure in 2010 or 2011, soon after I got the truck, to change both belts and tensioners, water pump, thermostat, etc.
I will look first time in the morning why this belt would have broken prematurely. Upper or lower balance shaft used/jammed bearings ??
If jammed bearings there are, will I just let it "as is", i.e. without the balance shaft belt, since it supposedlly activates a secondary oil pump, while a primary pump, activated by the main crankshaft, should suffice ??
May the force be with me...
Re: Help on oil leak diagnosis
Posted: Wed Oct 28, 2015 6:15 pm
by Growlerbearnz
The balance belt usually breaks because the crank seal is leaking- oil degrades rubber, and the balance belt is the first to get soaked. The balance shafts *can* seize, so check that they turn easily by hand.
Changing the crank seal is fairly easy. I'd also change the balance shaft seals too, while I was in there. I think running without the balance shaft belt is a cheap bodge. As long as you have everything apart to change the crankshaft seal, you might as well replace the balance shaft belt too- the engine really does run a lot smoother with it, and I'm not convinced the secondary oil pump is entirely optional- Mitsubishi put those piston squirters in there for a reason.