Low/No oil pressure below 1k rpm when hot

[DSM-sagacious]

After reading every post containing "oil pressure" ive decided to make my own post. I hope someone here can help.

Problem:
After the engine warms up (i.e. short drive or idling for a while) the oil pressure is below 5psi as read by my dummy light and mechanical oil pressure gauge when at/below 1k rpm. However, as the rpms go up the oil pressure is too high. For example 2k=25psi 3k=40psi 4k=60psi etc... So you could say i have a combination of high and low oil pressure really. I know the high pressure is due to the fact that i have no balane shafts and no oil squirters. I plan to port the oil housing as soon as i resolve this low pressure issue. I am running a 2.4l 2g block with a 1g head. I believe all my mods are accurately listed in my profile. I dont want to run a thicker oil than a 10w-30. It would seem a band aid to an underlying problem. The engine has only about 4k miles on it.
Please shoot me some ideas.
Thanks,
-Andy-

 

[GRAVEDIGGER]

I believe that porting the oil housing is for keeping the high oil pressure down a bit if that is the problem. It sounds like you are ok on your oil pressure with higher rpms, but as far as the low pressure at idle or below 1k, that sounds a little too low. But, porting the housing will just give you lower pressure I believe.

 

[DSM-sagacious]

Yes the high oil pressure i know how to fix. The low pressure is the main concern. Im fairly certain its not my oil pump because its new for one, and it produces plenty of oil pressure at higher rpms and when cold. Aslo i forgot to mention that the engine uses no oil and has no know leaks externally.

 

[JusMX141]

The same thing recently happened with a non-turbo 4G63 engine I rebuilt for a customer. It was a budget job, so he elected not to change the oil pump...which had 172k miles on it. I'm suspecting the oil pump to be the problem.

At idle with 10W30 and brand new bearings with proper oil clearances, the oil light would come on when the engine is hot. I combatted this by using 15W40 diesel oil...the light no longer comes on.


If you look up what Mistubishi recommends for our engines, 10W30 is actually the thinnest oil you should be using. They only specify 5W30 for climates that never go about 60*f.

 

[knochgoon24]

I believe that porting the oil housing is for keeping the high oil pressure down a bit if that is the problem. It sounds like you are ok on your oil pressure with higher rpms, but as far as the low pressure at idle or below 1k, that sounds a little too low. But, porting the housing will just give you lower pressure I believe.

The porting will only help your peak oil pressures. It won't affect your oil pressure at idle.

 

[DSM-sagacious]

I know i could use thicker oil, but like i stated earlier, it would only be a band aid to a problem that may get worse.

 

["G"]

What weight oil are you running? Where is your gauge getting its reading from?

After reading every post containing "oil pressure" ive decided to make my own post. I hope someone here can help.

Problem:
After the engine warms up (i.e. short drive or idling for a while) the oil pressure is below 5psi as read by my dummy light and mechanical oil pressure gauge when at/below 1k rpm. However, as the rpms go up the oil pressure is too high. For example 2k=25psi 3k=40psi 4k=60psi etc... So you could say i have a combination of high and low oil pressure really. I know the high pressure is due to the fact that i have no balane shafts and no oil squirters. I plan to port the oil housing as soon as i resolve this low pressure issue. I am running a 2.4l 2g block with a 1g head. I believe all my mods are accurately listed in my profile. I dont want to run a thicker oil than a 10w-30. It would seem a band aid to an underlying problem. The engine has only about 4k miles on it.
Please shoot me some ideas.
Thanks,
-Andy-

 

[DSM-sagacious]

Im using castrol synthentic 10w30. The gauge is fed from the oil filter housing where the stock sender used to be. Also i should probably mention im running an air to oil cooler.

 

["G"]

What's the coldest it gets in winter by you? Do you drive your car year round?

 

[DSM-sagacious]

This car is my dd and typicaly pretty warm in the winter here. Its usually about 60 some degrees but there is the occasional hard freeze.

 

[dsmfa9nutter]

You're in alabama, your winters are 40* at their lowest. Your oil pressure seems low to me actually. Although I'm running a BSE which raises it a little.

 

[knochgoon24]

Your car does exactly what my car does. I just turned up the idle so that it had enough pressure. It might also be because my exhaust is almost touching the oil pan. I'm planning on trying some exhaust wrap to keep the temp down there, but I don't think that's my problem. I didn't put the oil gauge in my car until I did the BSE, so I don't even know what was normal for my motor stock. In the summer, I'll run a bit heavier weight oil.

 

[DSM-sagacious]

Ive been looking more and the only thing ive found to try thats not thicker oil is a. replace the thermostat on the oil housing b. see if the oil pickup is loose c. replace the oil pump. Any other options you guys can think of?

 

[delta448]

A heavier oil is the best possible solution, it requires the least effort and should not noticeably hinder performance.

Did you remember the gasket for the oil pickup tube? Use a stubby shaft in the BSE? How were the bearing oil clearances when you built the engine?

 

[DSM-sagacious]

When i built the engine everything was in spec and brand new. I was pretty meticulous with everything i put together. The sump tube does have a gasket. I remember it being green and waxy and different from the other gaskets in the kit i got from slowboy. I tryed some super thick 20w50 i picked up from wal-mart today with no luck. My oil pressure is still too low at idle. The only things im down too now are A. sump tube is loose B. Bad (brand new) Oil pump and just thougth of C. Oil temp too hot?

Im running an oil to air cooler. Is the oil getting too hot a possibility?

 

[knochgoon24]

Is you downpipe touching your oil pan?

 

[Flash]

I'm getting the same issue. I replaced my stock oil filter housing with one from an EvoIII, and I put a pressure sensor right outside of it. I also run 10w30 Mobil 1. Just a bit weird.

 

[gst25401]

Just a quick thought. My car had the same symptoms, could'nt figure it out for nothing. Turns out one of the oil passages to the head had a crack in it. When the motor was cool it had good pressure, but as soon as it warmed up a little bit the crack would open and drop the oil pressure.

 

[talon_swift7834]

i also have the same issue , but i have the forward facing oil filter bracket with no oil cooler. I'll see what happens when i put on my new aluminum oil pan that holds a quart more of oil.

 

[DSM-sagacious]

I seriously doubt a bigger oil pan will solve this type of problem. Tomorrow i am going to drop the oil pan and have a look arround. If its not the sump tube loose then i have a feeling ill be giving slowboy a call about a defective Topline oil pump/front case.

 

[JusMX141]

If its not the sump tube loose then i have a feeling ill be giving slowboy a call about a defective Topline oil pump/front case.

Sounds like a great idea. Sort-of sounds like Ricky's issue with Topline pumps last summer:

http://www.dsmtuners.com/forums/new...-cap-now-purple-after-only-300-miles-use.html

Perhaps they work well on a non-turbo 4G63 daily driver....but on a turbo DSM spinning 8k regularly, apparently Topline just doesn't cut it.

 

["G"]

Who buys anything from slowboy anyway?

 

[JusMX141]

It's not Slowboy's fault that Topline pumps are sh!tty.

Everyone has their faults.


I'm not one to link to other forums, but here's an interesting post concerning Topline's reliability:
OEM vs aftermarket front cases

 

["G"]

It's sb's fault for even selling it, as if it were good. It's a case of the blind leading the blind.

 

[JusMX141]

Trust me, don't think I'd defend Slowboy for any reason....I'm just stating that they didn't build the pump so you can't blame them. Perhaps they will stop selling Topline when enough defective pumps get sent back.