Hey guys,
I have a 92 gsx. It came with the 90 style air oil cooler on it. In putting the car back together I found holes in both oil cooler lines as well as a leak in the cooler itself.
I have to get this car on the road by the beginning of the week and I have read that people do delete them altogether.
I don't know if I can loop them or if I can just thread bolts into the housing to block it off.
What is the best way to cap off the ports for the cooler on the filter housing?

Thanks for the help.

The most straight forward way to get around the cooler would be looping those ports. However, you can plug them if you remove the oil cooler bypass valve and put in an appropriately sized plug to seal the housing so that oil has a direct path from the filter to the engine. No idea what the thread size is for that valve on the housing, but plugs for the original line holes can be found at a hardware store.

Can anyone chime in on the bypass issue? I blocked to the two ports where the cooler inlet and outlet go into the oil filter housing, but I'm concerned about the bypass. Am I ok running it as is or do I really need to replace the bypass? The last thing I want is to be starving the engine of oil.

The bypass valve is basically an oil thermostat. If the the oil is too warm, it will elongate and seal off to force the oil through the cooler. If there's no cooler (in other words, the cooler ports are blocked), I wouldn't expect good things to happen without removing the bypass as well. Solution? Pull the valve out, pull off the c-clip, and remove the spring for the valve.

Where is the bypass?

The bypass is the 22mm bolt that sticks out of the end of the oil filter housing. If you unbolt it there will be a spring and "piston" which is the bypass. Check out the oil port mod "how to" in order to get more info: http://www.dsmtuners.com/forums/articles-engine-fuel/319342-oil-pressure-relief-valve-porting.html

So could I not just remove the spring and piston and put the bolt back in?

easiest way get a non turbo ofhing.

lkq $11 ish for a cooler... just sayin

Well I have to drive the car tomorrow. I wont be able to get a n/t ofh. But even my 90 n/t have the cooler on it. I might just go ahead and pull the spring and piston unless someone can confirm that I should not.

ilco187 said:

lkq $11 ish for a cooler... just sayin

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I was just about to say that, you beat me to it!

the threads on the oil filter housing are bspt not going to be available at most local hardware stores as its not a common thread in america. jnztuning and extremepsi sell them though.

No mine had the air cooled setup on it, not the water cooled. I already have those ports capped. The lines and the cooler leaked. The whole setup was bad.

3kgt2nv said:

the threads on the oil filter housing are bspt not going to be available at most local hardware stores as its not a common thread in america. jnztuning and extremepsi sell them though.

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I found the bolts to replace the banjo bolts in the housing for the cooler. They are already installed. What Im trying to figure out now is how to stop the bypass from routing oil to the ports for the cooler that are now blocked off.

I will be putting an aftermarket cooler on it this spring, but right now money is too tight for that.

Ravenous said:

The bypass is the 22mm bolt that sticks out of the end of the oil filter housing. If you unbolt it there will be a spring and "piston" which is the bypass. Check out the oil port mod "how to" in order to get more info: http://www.dsmtuners.com/forums/articles-engine-fuel/319342-oil-pressure-relief-valve-porting.html

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No. That is the oil pressure relief valve. You most certainly DO NOT want to remove the spring and ball from that.

Refer to posts 3 and 4 here for what the different spots on the '90 oil filter housing are: http://www.dsmtuners.com/forums/turbo-system-tech/409331-6-bolt-swap-90-ofh-turbo-feed.html.

I haven't personally had my bypass valve out, but assuming this is correct, it looks like you could simply remove the spring: Foro Mitsubishi 4x4 Galloper Club - Problemas con la valvula bypass del enfriador de aceite del motor - Mecanica.

EDIT#2: On my own vehicle, I am running a '90 OFH without a cooler. The cooler ports are blocked off. I did as suggested above and jshuman states he did in post #20, removed the spring and c-clip, and reinstalled the valve. Absolutely zero issues.

Edit: And to nip this one in the bud, many many Mitsubishi vehicles use the same bypass valve.

19Eclipse90 said:

No. That is the oil pressure relief valve. You most certainly DO NOT want to remove the spring and ball from that.

Refer to posts 3 and 4 here for what the different spots on the '90 oil filter housing are: http://www.dsmtuners.com/forums/turbo-system-tech/409331-6-bolt-swap-90-ofh-turbo-feed.html.

I haven't personally had my bypass valve out, but assuming this is correct, it looks like you could simply remove the spring: Foro Mitsubishi 4x4 Galloper Club - Problemas con la valvula bypass del enfriador de aceite del motor - Mecanica.

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Yeah, you don't want to remove the one on the end, that will drop the oil pressure to nothing. The oil bypass valve is the one with the brass cap on the bottom of the filter housing. I don't have one to look at the passages, but i would assume with the ports blocked off if you were to remove the bypass valve than the oil would just flow normally thru the filter. Don't assume that my assumption is right though. Go over the passages and make sure that it will flow correctly before even attempting it.

My sincerest apologies I was thinking it over in my head earlier and couldn't come up with how the relief could work like a thermostat with just a spring and piston. I had the two confused. I am truly sorry for the misinformation.

dude, your oil filter housing is a badass rare one. there 1990 or japan only. dont F with it man. so your lines leak and the cooler its self is leaking. well, if it were me, id just replace the cooler and relocate it to a much better front mount location. as far as the lines go that are leaking. you can chop the metal off and home-made flair em out a bit. like where they bolt up to the oil filter housing, you got two LARGE banjo bolts conecting to the oil filter housing. it takes a 24mm socket to loosen these bolts. thses are the lines that are leaking. the come out of the banjo bolt and are metal for a few inches befor they turn to rubber. right there where there metal you can cut em nice and homemade flair em to accept 3/8" hose. use a quality oil resistant hose and double clamp the hoses and run them up to your new cooler. it could be a junkyard ATF cooler off a old van or pick up truck. trust me, do it this way dont delete it. you have a nice set up, take adtvatage of it. i have the same one and i ran double hose clamped hoses up to a HUGE B&M tranny cooler. i use it as a front mount engine oil cooler and it has its own small fan on it as well. trust me, keep the cooler dont bypass it

Ravenous said:

My sincerest apologies I was thinking it over in my head earlier and couldn't come up with how the relief could work like a thermostat with just a spring and piston. I had the two confused. I am truly sorry for the misinformation.

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Eh, the "thermostat" talk may be a bad analogy... All I meant was that it expands with temperature like one. It is different because, as it expands, it blocks the flow through that port whereas a thermostat would generally allow flow. The biggest takeaway here is that a "relief" and a "bypass" are not necessarily the same thing.

Dont bypass it keep it hooked up and repair it

I went ahead and removed the bypass. Well not the whole thing. I just took the c clip off so I could reoved the piston and spring and reinstalled the bolt. Oil pressure looked normal. I drove it for about 30 minutes including sitting in a drive thru for a little bit. I pulled the oil cap when I got home and it looked as if the head was getting all the oil it needed and I never heard lifter tick or any other signs of oil starvation.

jshuman said:

Hey guys,
I have a 92 gsx. It came with the 90 style air oil cooler on it. In putting the car back together I found holes in both oil cooler lines as well as a leak in the cooler itself.
I have to get this car on the road by the beginning of the week and I have read that people do delete them altogether.
I don't know if I can loop them or if I can just thread bolts into the housing to block it off.
What is the best way to cap off the ports for the cooler on the filter housing?

Thanks for the help.

Click to expand...

I know this is a million years later, but did you find out the answer? I blew an oil cooler line today and have to drive it for a little while before I can take the front end apart to fix it. Intuition is telling me it's ok to just tread 16mmx1.5 drain plugs in and drive it around.

talontime69 said:

I know this is a million years later, but did you find out the answer? I blew an oil cooler line today and have to drive it for a little while before I can take the front end apart to fix it. Intuition is telling me it's ok to just tread 16mmx1.5 drain plugs in and drive it around.

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Yeah this is old
No. Don't just block off only the two ports for the oil cooler. Once the oil gets hot, you would loose a lot of oil flow to the main oil gallery and would possibly damage bearings. Just loop the two oil cooler ports is the easiest and the safest. Or if you would like to block off the two ports, then remove the oil cooler bypass valve and block off its port, too. I think the port is M24 x 1.5. (or if you have an extra bypass valve just cut/remove the bypass valve rod/the thermostat part and use only the threads part or disassemble the bypass valve like the pic and use it "only temporary" to block off the port, since the rod and the thermostat part that come when it gets hot would still restrict the oil flow, so I don't recommend much but it would have much more oil flow than just block off the two ports)