Resolved 1G 6 bolt timing belt tensioner oil leak

[all black 4G63]

Does anyone have a final remedy to address the oil leak from the lower timing belt tensioner bolt on a 6 bolt? (photo attached)

I have read post, but wanted to get a fresh suggestion as most post are from early 2000's

I have used 3 bond on the bolt, but obviously it still leaks.

Also is there any other areas for potential oil leaks behind the timing belt cover that I should be aware of?

Thank you for the support

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[all black 4G63]

Yes I’m 100 % sure it’s the front cover gasket area at the top of the cover.
The head gasket and any where above the cover is completely dry.
the front cover is brand new OEM.
the oil only comes out when sustaining high RPM highway driving keeping it around 4-5000 RPM for extended time. The whole time the oil pressure is high as hell.
this is literally the only thing left.
actually the head gasket is new HKS MLS with freshly decked block and machined head.

 

[DSMPT]

Is your front case gasket OEM or aftermarket? and where are you reading the oil pressure? If you are constantly seeing 100+ psi it would possibly leak but generally only 90 psi wouldn't blow the gasket if it's installed properly.

 

[all black 4G63]

It’s oem gasket.
hopefully porting the OFH housing will address this finally and for good..

The AEM oil pressure gauge is tapped in where the stock oil pressure switch used to live on the OFH

 

[AWD-Tony]

Is your front case gasket OEM or aftermarket? and where are you reading the oil pressure? If you are constantly seeing 100+ psi it would possibly leak but generally only 90 psi wouldn't blow the gasket if it's installed properly.

Wouldn’t it leak at that high pressure at low rpm since the engine rpm’s are low and isn’t pushing the oil?

 

[all black 4G63]

it pretty much leaks all the time

Are there any good pictures of OFH porting??

 

[AWD-Tony]

Here is mine. Watch Jafro's video I linked above 23minutes in and he'll describe what area(s) to open up.

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[all black 4G63]

thanks a lot man!

 

[all black 4G63]

does anyone know what OFH this is? it's off of a junk yard 6 bolt there no coolant flow to it.
what is strange is that there is no oil pressure sensor or tap for it underneath

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[all black 4G63]

Well I ported it and the pressure is the exact same. 3000 RPM=72 PSI
Stupid me i forgot to take a picture of the port job

 

[DSMPT]

Wouldn’t it leak at that high pressure at low rpm since the engine rpm’s are low and isn’t pushing the oil?

From my experience, no, as long as if everything is installed and sealing properly.
I had been running without having the OFH ported, balance shaft and oil squirters for many years with many builds. I have never had a drop of oil leak from front case gasket, even I had been seeing 90-100 psi steady pressure always at the mid/high rpm, when pull hard it would exceed 100 psi in 1st gear. (But if the pressure relief valve is properly working, it would settle in 95-100 psi shortly) and in 2nd/3rd/4th gear it wouldn't exceed 100 psi. The oil pressure at low RPM was maybe even a bit higher that what the OP said.
I saw a couple of times that oil leaked from front case/OFH gasket on my customers cars. All had the pressure relief valve plunger rusted and stuck closed.

I don't know how the OP is reading the oil pressure, if he is reading the gauge while driving or he is logging the sensor signal. What I started to think is, IF the leak is really occurring where the OP mentioned, then maybe the actual oil pressure is much higher than he is reading for some reason, like something is clogged somewhere in the oil passage, if that's the case, I think porting the OFH does not work.

 

[AWD-Tony]

From my experience, no, as long as if everything is installed and sealing properly.
I had been running without having the OFH ported, balance shaft and oil squirters for many years with many builds. I have never had a drop of oil leak from front case gasket, even I had been seeing 90-100 psi steady pressure always at the mid/high rpm, when pull hard it would exceed 100 psi in 1st gear. (But if the pressure relief valve is properly working, it would settle in 95-100 psi shortly) and in 2nd/3rd/4th gear it wouldn't exceed 100 psi. The oil pressure at low RPM was maybe even a bit higher that what the OP said.
I saw a couple of times that oil leaked from front case/OFH gasket on my customers cars. All had the pressure relief valve plunger rusted and stuck closed.

I don't know how the OP is reading the oil pressure, if he is reading the gauge while driving or he is logging the sensor signal. What I started to think is, IF the leak is really occurring where the OP mentioned, then maybe the actual oil pressure is much higher than he is reading for some reason, like something is clogged somewhere in the oil passage, if that's the case, I think porting the OFH does not work.

He has AEM gauge. Think he can shim the bolt to bring down the oil pressure but that may not fix the leak from what you're saying.

@all black 4G63 guess the oil leak is still there?

 

[all black 4G63]

Yes the oil spits everywhere with the timing cover off as the belt slings it all over.
This sucks.
The block was just rebuilt, honed and new race bearings. it has JE pistons and crower rods.
I’m running 10-30 non synthetic for break in. I have 160 miles on the block.
My gauge is tapped in at the OFH it’s a brand new AEM 0-150psi X series
I just don’t get it. Cruising at 3000-4000 rpm is 75-85 PSI
The block was cleaned at the machine shop, so if there is a restriction in wonder where it is?

the oil/car is killing my

 

[Mech Addict]

Even though your gauge is new, have you verified it reads correctly against another pressure gauge? From these posts it seems more related to the leaky spot, not the overall pressure.

I had trouble with my turbo oil return at the pan. Took like 5 tries. Double gasket and copper spray on every surface did the trick for me. Redoing that each time is nowhere near what you’re having to redo each try. Hope you get yours sorted.

 

[DSMPT]

I just don’t get it. Cruising at 3000-4000 rpm is 75-85 PSI

Yes, your oil pressure is in high side but IF this leak is caused by high oil pressure and leaking from the front case where you mentioned, then I can imagine is as I already said before.

1. Assuming the pressure number you mentioned is true, physically it's not sealing well for some reason. Maybe the front case or block side is not flat or damaged.
2. The actual oil pressure may be way higher than what you are reading. If that's the case, most likely the pressure relief valve is stuck closed or the plunger is not sliding smoothly since you mentioned that you already ported the OFH and it didn't change the oil pressure.

actually the head gasket is new HKS MLS with freshly decked block and machined head

This doesn't guarantee anything.

My gauge is tapped in at the OFH it’s a brand new AEM 0-150psi X series

This doesn't guarantee anything neither. Are you logging it?

Well I ported it and the pressure is the exact same. 3000 RPM=72 PSI

This sounds something is not right. Assuming if you ported properly, this means like as I have been telling you that the pressure relief valve is stuck closed or the plunger is not sliding smoothly. Or/and the pressure gauge is not reading precisely. Whatever something is not right.

 

[all black 4G63]

Thank you DSMPT for your time reading through this thread and my nightmare.

The photo of where the oil leak is coming from is in a previous message I sent earlier in this thread I attached it agin.

I think the gauge is working because it reads above 100 PSI when the motor is cold and 14PSI hot idle.

The front cover and gasket are new Mitsu OEM parts. When the cover was removed to replace the gasket for the second time the block appeared flat and I can't imagine the brand new OEM front cover is warped. I have never over heated the engine.

With all the shit that I have done to address this leakI can't fathom it anymore other then it escaping due to high pressure. I realize others have had similar pressure with no leaks, but I don't know what else to do.

I have another OFH I will swap it and see what happens I will also use a mechanical gauge after I swap/

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[NOSLO2PT0]

What about trying this? Spraying the whole side down with brake cleaner until it’s perfectly clean. Then run the car on jackstands at higher rpm and try to physically watch to see where the leak develops

 

[all black 4G63]

I have done this it’s impossible to see because of the water pump and crank pulleys. However I pretty sure based on the photo that the leak is the front cover gasket

 

[talon77]

I know you have everything back together already and it still (frustratingly) leaks, but if you have any interest in ruling out that front case gasket, maybe consider taking off the timing belt and spinning the pump sprocket with a drill, like you are priming the motor (if you have room to do so). Ive seen a YouTube video where spinning the pump with a drill can generate as high as 35 psi, not sure if you are leaking at that pressure. You might get a much clearer view and video at things with the idler and tensioner pulleys and stuff out of the way. Just another avenue for you to try if you want… I’m sure it’s not that appealing though since your stuff is back together.

 

[DSMPT]

I think the gauge is working because it reads above 100 PSI when the motor is cold and 14PSI hot idle.

This doesn't sound you have very abnormal high pressure. Maybe just a sealing issue or the oil is coming from somewhere else.
But if that 100+ psi pressure is not a spike, and if the pressure steadily stays 100+ psi for some time, that may be the issue.

I forgot to ask one thing, are you using a 90 OFH with external oil cooler? If so, did you inspect the bypass valve and the oil cooler's flow? This would possibly cause high oil pressure. It's a rare case but technically if the bypass valve and the cooler are both clogged (or just block off the oil cooler ports), you would have more pressure ONLY when oil temp gets hot and ONLY at the pump side and gets less in the block.

I do understand that this is very frustrating.

 

[AWD-Tony]

You can also run the car without the water pump & crank pulley. Obviously keep an eye on the temp.

 

[all black 4G63]

I know you have everything back together already and it still (frustratingly) leaks, but if you have any interest in ruling out that front case gasket, maybe consider taking off the timing belt and spinning the pump sprocket with a drill, like you are priming the motor (if you have room to do so). Ive seen a YouTube video where spinning the pump with a drill can generate as high as 35 psi, not sure if you are leaking at that pressure. You might get a much clearer view and video at things with the idler and tensioner pulleys and stuff out of the way. Just another avenue for you to try if you want… I’m sure it’s not that appealing though since your stuff is back together.

Talon 77 thanks for the replay
I use a drill with a 14mm to prime the oil system and I wait until I can see it coming out of the followers (rockers) up top. I’m not maxing the drink speed when i do this but I didn’t notice oil coming out anywhere else.

This doesn't sound you have very abnormal high pressure. Maybe just a sealing issue or the oil is coming from somewhere else.
But if that 100+ psi pressure is not a spike, and if the pressure steadily stays 100+ psi for some time, that may be the issue.

I forgot to ask one thing, are you using a 90 OFH with external oil cooler? If so, did you inspect the bypass valve and the oil cooler's flow? This would possibly cause high oil pressure. It's a rare case but technically if the bypass valve and the cooler are both clogged (or just block off the oil cooler ports), you would have more pressure ONLY when oil temp gets hot and ONLY at the pump side and gets less in the block.

I do understand that this is very frustrating.

Yes it is a 90 OFH it is brand new as well. I bought it from STM before they were discontinued. It has at around 600 miles on it. However, on the other hand the cooler is 30 years old and “looks” like shit. I have honestly never really check it for restrictions. If it was restricted I would have high oil pressure, but would that high oil pressure be in the path of the front cover oil passage ways? I would think it wouldn’t make it to the cover if the cooler was restricted because it flows through the filter then the cooler then engine. If I’m pissing out of the cover I would imagine it’s because of high oil pressure because the the cover and gasket are brand new and I applied 3 bond to both sides.
what do you think?
my only thought is the OFH regulator is binding?

You can also run the car without the water pump & crank pulley. Obviously keep an eye on the temp.

Homely where would the oil be coming from other then what is shown in the photo?
Everything on the front of the motor is new.

 

[DSMPT]

90 OFH it is brand new as well

Since it's new, maybe it's not the case but anyways just in case you should inspect the pressure relief valve plunger if it's sliding smoothly or not. The one in the 1st pic below.

would that high oil pressure be in the path of the front cover oil passage ways?

If the oil cooler is clogged/restricted or the oil cooler ports are blocked off and still has the bypass valve, where the red line part in the 2nd pic until the oil cooler outlet port on OFH is where may get higher pressure when the oil temp gets hotter. (the blue circle is where you are suspecting the leak)

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[DSMPT]

the cooler is 30 years old and “looks” like shit. I have honestly never really check it for restrictions.

You can loop the ports on OFH to bypass the cooler. And you can see if it would make any change on the oil pressure without the oil cooler.

 

[all black 4G63]

I will loop the ports today and see
Thank you very much for the info

 

[all black 4G63]

You can loop the ports on OFH to bypass the cooler. And you can see if it would make any change on the oil pressure without the oil cooler.

Hey I think you're right about the oil passage way.. I never thought about it, but the oil leaves the pump and travels in that passage way in the upper front cover to the OFH.

If there was a restriction in the cooler itself I don't think that would cause my high oil pressure problem because of the bypass and the fact that my oil pressure on cold start is over 100 PSI and stays there for quite a while (90-99PSI) this should be during bypass (cold engine).

However, if the pressure regulator is not functioning than this would explain everything.... i hope.

I will swap the OFH and bypass the cooler now. If this doesn't make a change then I going to assume I have a restriction in the oil galleys somewhere in this engine. However, I just got the block honed and cleaned at a reputable machine shop here in Chicago (Apex Engineering) and I also visually inspected the oil galleys before I assembled the block, everything looked OK.
This all happened in early October. However, the oil leaking out of the top of the cover occured before taking the engine to the machinist.