Help with head gasket job

Hey guys,

Some of you may know that my 1990 Mitsubishi van needs a head gasket. I am a virgin when it comes to this sort of work. I have torn into it pretty well so far, but I have a few questions. I have a Factory shop manual coming from eBay soon, but thought I would ask anyway. The engine is a Mitsubishi 2.4 litre 4G64 I think.

The timing belt tensioner had a bolt on it that is in a slot. I loosened it up and thought it would allow the tensioner to slide in the slot to relieve the tension so I could remove the belt. Well that didn't happen. It has a pivot point that has a spring on it that I was able to get the spring tension relieved by pulling the back of the spring from its perch on the water pump housing but the tensioner still hasn't moved. The pivot point has an allen head on it that I want to turn, but when I try it doesn't want to budge and I don't want to force it with more leverage, and break something by doing it wrong.

I did get the belt off anyway but there is no way I can get the new one on there the way I got the old one off. Also I can see a mark on the main pulley and a spot where I think it should line up with, and also one on the balance shaft pulley. I can see a dot on the cam shaft pulley but no corresponding mark on the head or block to line it up with. Any ideas on that? I am sure the book will tell me but thought I would ask before I get it. Should I replace the balance shaft belt as well as the timing belt while I am in there? What are your thought son the water pump? It looks fine but maybe with all the oil in the coolant it should be replaced. It actually looks really new, but I really don't know for sure.

Would you guys recommend having the head looked at by a machine shop even though it never overheated? I was told by the seller of the van that the guy he bought it from had done a head gasket on it recently, but it sure doesn't look like it. If I can manage it will it be okay to remove the head with the intake manifold still bolted to it? Is it okay to bolt the head back on with it in place if I can get it all in there? Is a Gates belt a good name for the timing belt? What about the head gasket brand? Is getting the factory Mitsu head bolts at $5 a piece worth it,or should I shop around? I asked my local NAPA friend but he can't get them. RA doesn't list them either.

On the subject of the oil in the block and cooling system, what should be done to clean that out? Should I just hose out the radiator the best I can or get it cleaned by a radiator shop?

Any help on this subject would be greatly appreciated. Remember I am a rotary guy. Surprisingly this van hasn't been too tough to wrench on so far but it is a lot different than an old Mazda rotary vehicle. The engine under the seats is odd, but I like odd.

Chris

In reply to Mazdax605: rockauto.com has head gaskets from $12.57 to $26 for Fel Pro or Victor Reinz. No head bolts though. I would get head checked to be sure it is flat or you will be back inside engine soon. Also have a good look for cracks, some Mitsu. heads were prone to cracking. I can't offer any help on your other questions, they don't have pushrods so I am outside of my turf. Daryl

If you have any suspicion that the engine has over heated you need to check the head for flatness, (Lack of warpage), and possibly the block as well, if the block is aluminum. Check your new manual.

If you can get the radiator flushed for a reasonable charge, ($50 or less) do that. Otherwise wash and rinse it several times with a mild detergent. Oil in the coolant will not affect the water pump, but if it is a PIA to replace the water pump in the car, replace it now.

The shop manual you have on order will tell you if you need to replace the head bolts.

Ease of disassembly/assembly will almost always tell you to remove/assemble the intake manifold separately. (This may be different on your motor)

Many of your questions will be answered by the manual you have ordered. You need to get hooked up with a Mitsui forun for the the other questions.

Good luck!

Rog

I think that link I gave you earlier from the Galant forums say the head bolts are torque-to-yield, so they will need to be replaced. You might as well go with ARP head bolts while you're at it.

When I do a timing belt I replace everything: Belt, idlers, water pump, tensioner, and whatever else is in the area. I hate doing things twice and the tensioner, water pump, or idlers can all wreck a nice new belt if they fail.

I plan on changing the head bolts but I can't seem to find them at either Rock Auto or my local NAPA. My next check is at the other FLAPS around here,but I know I can get them at the dealer but $5 a piece seems kind of steep to me. I would love ARP head bolts but can't seem to find them either.

Chris, drop the head off over at my house and I'll take the head to my engine builder to get checked out. Cheap insurance. You can snag your chainsaw when you come by.

Found a place online that has factory mitsu parts at a discount. The head bolts are $3 and change a piece instead of the $5 the dealer wants. I guess I will have to pay shipping but the savings may be worth it. Have to check on that. The tensioner thing still has me licked though. I don't want to break anything. Would a factory mitsu head gasket be better than say a fel-pro? How about the timing belt compared to a Gates?

So I got the head of this afternoon with the intake attached to it still. The head gasket does indeed look to be newer. I just don't know why it failed. Maybe they re-used the head bolts and that caused an issue. maybe the head is warped.

While my BIL was helping me this afternoon he mentioned I should use one of the many rotary engines that I have laying around. I thought that may be interesting but I would have to source an automatic transmission as there is no way I am capable of rigging up a manual in this van. Does this idea sound crazy? I have basically everything short of the trans laying about and I think it will all fit in there. Of course I would be going carb'd as I don't have anything rotary that is fuel injected. I would like to keep it injected but this would be on a budget. Again, does this sound doable, or crazy? I know an automatic rotary is kind of a buzz kill, but then again it sure would be different.

Tell me what you think.

Chris

Is there ever something wrong with swapping in a rotary engine?!

Build thread please.

It needs a manual rotary. You just need to have someone ride in the back seat to shift.

Hey guys,

So I have disassembled the engine to the point of having the head off. It looks like the seller wasn't lying about the head gasket being done recently before he bought it. Now I don't have a clue as to why it was leaking again. Did they do a poor job on it? Is the head warped? Did they use the head bolts over and they are stretched and therefore not torquing up correctly? Did they use lousy parts when doing the job? My guess is that the head may be warped as there wasn't a thermostat in the housing either so maybe this was due to an overheating problem. Also I was thinking that maybe the head is cracked, but that is unlikely, correct?

Any ideas? Should I break down and have the head looked at? How much of a pain in the ass is it to disassemble the cam shaft and valves if that needs to be done so that a machine shop can have a look at it? Remember i am a rotary guy and this is my first ever head gasket job.

Thanks guys,

Chris

Hmmm. Head gasket recently replaced but no thermostat in the housing. That tells me someone knew something was funny.

Have the head checked for warpage and cracks. I'd say pull the cam but not the valves, let them look at all of that for you. If the head passes (and it will probably be okay, the days of easy crack aluminum heads are long gone) when you reassemble the engine pay particular attention to the torque specs and pattern. OBTW: according to the Mighty Max forums the head bolts are definitely torque to yield so they will need to be replaced. If the head gasket has a shiny gray finish, that's graphite and you don't want to use head gasket copper coat etc on those.

Use a thermostat on reassembly. If the engine never gets to operating temp, it will get poor gas mileage and the transmission may shift funny. It looks like the thermostat for that engine is 'offset', meaning you need to be careful about how you install it or it can't open all the way. Also make sure it has the 'jiggle pin' or it will take for frickin' ever to burp air from the cooling system.

I have had good success getting oil out of cooling systems using that Siloo brand cooling system flush stuff. I'd do it twice, the first time go put about 10 or 15 miles on it, drain the system and flush with straight water, the second time run the engine for about an hour then immediately drain/flush with clear water/refill with 50/50 coolant. The biggest concern with oil contamination of the cooling system is having hoses puff up and get soft since oil attacks rubber.

The 'no thermostat' makes me think there may be an overheat problem. You might want to take the radiator to a radiator shop to have thoroughly checked for blockage. I had a Courier pickup which ran perfect around town, get it on the hwy and wham it would run hot. Turned out about half of the radiator was clogged with that 'head gasket in a bottle' crap.

FWIW I have a 2.4 that came as a spare with the ex-Doug Sheppard rally Colt I had. I've never touched the engine(actually, I need to make sure it's still in my friend's shed). I was told it had a built head, but was pulled due to low compression in one cylinder.

I'd make you a heck of a GRM deal on it.

I was actually flushing the radiator out on Saturday with some fresh water from my garden hose,and noticed the few tubes I could see through the cap neck were gummed up with some sort of gink. I can only assume the rest of the radiator looks the same. It has never got hot on me in my short ownership but then again without a thermostat it won't I suppose. Now this van is getting expensive!!

Pete I am very interested in the head if you would be willing to ship it.

Chris

Chris,

I always replace a radiator when doing a head / head gasket unless I know for sure what its history. For the most part head gaskets die due to something else going wrong with a motor. Thermostat, cooling fan, clogged radiator etc. All can cause an overheat that will cause the head gasket to fail and possibly damage the head (cracking or warp-age)

Get the head looked at / magnafluxed. If you don't have a place to do it I know a good machine shop that will give you the strait scoop on your head. No price brakes with him but he is reasonable and I trust his judgment. I have been using him for 25 years.

So the head is cracked!!! Really badly at that. I need a new/used head. Pete could you please email me at cdirado837 at gmail dot com so we can talk about buying that head you have if it will work with my engine?

Chris

I stumbled on this

http://www.autopartswarehouse.com/details/QQMitsubishiQQVanQQReplacementQQCylinder_HeadQQ19871990QQREPM315802.html

Here's one I found on eBay. It comes with a handy list of other applications should you decide to go junkyarding for a used cylinder head.

http://www.ebay.com/itm/New-Cylinder-Head-Ram-50-Pickup-Dodge-91-90-Mitsubishi-Mighty-Max-92-Van-89-Car-/250851654574?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3AMitsubishi|Model%3AVan&vxp=mtr&hash=item3a67ec7bae

In reply to Mazdax605:

I need to find out if it's still there - oh, and BTW it supposedly had a "hot cam" too. I'll try to get a hold of him tonight.

Any luck, Pete?

Chris

Actually, I just talked to him a few minutes ago and he's going to check the garage and get back to me(he's moved so it'll probably be tomorrow before he goes over there).

Thanks!!

In reply to Mazdax605: About the tensioner; I recently did a timing belt job on a friends Galant, I think it has the same engine. There are two parts to the tensioner, the sloted pulley that you mentioned, is attached to a bracket that is connected to a hydraulic tensioner.

You have to remove the hydraulic tensioner and reset it. Or better yet replace it with a new one. Your manual should have instructions about sequence to set the tension with a new belt.

Good luck with the head.

No hydraulics on this engine. Figured it out. Just was being a Bob Costas about the allen head bolt,and didn't force it enough.