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4age 20v high oil temps

Posted: Tue Nov 21, 2017 9:50 pm
by Sultan
Hello everyone,

I just got done rebuilding my engine and on the break in period. Im close to finishing the break in period and pushing to car hard now to 7000rpms, but the oil temps seem to climb high around 260f which is about 125c and I don't know why they are so high, i'm using an oil cooler with the MRP oil cooler sandwich and oil filter relocation kit and because i'm using a oil cooler the temps shouldn't be that high. The oil temp sensor is taking temps from the oil filter relocation plate and the lines going to the oil filter seems to be very hot, I know the oil thermostat isn't stuck closed or anything because it suppose to open at around 82c to let oil flow to the oil cooler and I can feel the lines start to get warm at that temperature so I know oil is flowing to the cooler however the line going to the oil cooler only seems to feel warm to slightly hot and return lines feels cool so im guessing its doing its job?
im using the AMSOIl break in oil 10w-30
outside ambient air temps are about 25c 78f

I uploaded a video to youtube to show you how exactly my oil setup is, I stuck red tape on the oil line where it starts and ends for clarity

Please give me any insight maybe I should take oil temps leaving to oil cooler instead?

Re: 4age 20v high oil temps

Posted: Wed Nov 22, 2017 3:14 am
by jondee86
Hiya... can you please describe how the hoses connect to the oil cooler ? Are they at the
bottom on opposite sides ? Like in one side and out the other ? Or is there one connection
at the top of the cooler and one at the bottom on the same side ? Just need to make sure
air is not getting trapped inside the cooler.

Also, what level of modifications have been made to the engine ? More power means more
heat so everything will get hotter than on a stock engine.

Cheers... jondee86

Re: 4age 20v high oil temps

Posted: Wed Nov 22, 2017 11:26 am
by Sultan
Hey there,
The lines are connected on the bottom side of the cooler the inlet and outlet lines are close to each other,

I took it to my mechanic and we noticed the inlet oil line gets hot but the outlet line is cool same thing goes with the cooler one side of it is warm while the other side is cool which can only mean one thing, i'm suspecting there's something clogged up inside where the outline line is, I never even thought about that because I asked the place that built my engine to clean the oil cooler before fitting it back which they did but they must of left some tissue or something inside and forgot about it and hooked it back up. Im really annoyed about this and will let you know tomorrow if there is indeed something clogging it up.
Do you think the engine bearings suffered or anything because of this? 125c is hot I know but not something to catastrophically high

The engine is built toda pistons and cams along with cnc ported head, the engine will be dynoed sometime this month and I can share my power if you would like


Re: 4age 20v high oil temps

Posted: Wed Nov 22, 2017 12:55 pm
by jondee86
This is how I understand an oil cooler with a thermostat works...

The thermostat is designed to open and close to regulate the engine oil temperature.
When the oil is cold the thermostat is closed. When the temperature gets to around
185degF the thermostat starts to open and allow oil to flow to the cooler. Only some
of the oil goes to the cooler, but if the temperature goes higher the thermostat opens
further, and more of the oil is sent to the cooler.

The oil cooler is a radiator which transfers heat from the oil to the air passing thru
the cooler. In normal operation, the side where the oil enters will be hot and the side
where it leaves will be cooler. How much cooler depends on how much oil is being sent
to the cooler, and how much air is passing thru the fins.

If the hose from the engine to the cooler gets hot all the way to the entry to the cooler,
then oil is flowing. If there is a temperature gradient from the cooler inlet to the
cooler outlet, then the cooler is working. But, the cooler should be designed to force
oil to use all the passages inside so that the whole of the cooler is losing heat, not
just one side. So one side (edge) should be hot the same as the top of your water
radiator gets hot with water spreading across the header tank.

My question related to the position of the hose connections on the cooler. If they are
both at the bottom, then there is a possibility that air can collect inside the cooler and
not be able to escape. If the cooler is half full of air, then only one half of the cooler
will be working to cool your oil. It is highly recommended that at least one (the outlet)
of the oil cooler connections be at the top to allow air to escape. Preferably both
connections should be on top.

This may be your problem if the cooler appears to be working, but not working as well
as you had expected.

The oil cooler thermostat is designed to keep your oil temperature within the optimum
operating range of (say) 85 to 100degc. It is closed to get the oil up to temperature
quickly, and then it opens to make sure the oil does not get too hot. I25degC is at the
point where your oil will start to degrade, but providing you have good oil circulation
it should not have caused any damage.

Hope this helps :)

Cheers... jondee86

Re: 4age 20v high oil temps

Posted: Wed Nov 22, 2017 8:14 pm
by Sultan
Thanks Jondee, I will look into that maybe Ill get a different oil cooler and see what happens, the thing is this oil cooler was installed on my other car years ago and work really nicely but I cant remember how it was mounted exactly.
both the oil cooler lines are connected at the bottom of the oil cooler this is the video of my setup


Re: 4age 20v high oil temps

Posted: Wed Nov 22, 2017 11:50 pm
by jondee86
Maybe you can rotate the cooler so that both hoses enter on top or at the
top of one of the vertical sides ?


If the cooler worked before, it should work again :)

Cheers... jondee86

Re: 4age 20v high oil temps

Posted: Fri Nov 24, 2017 8:34 pm
by Sultan
Hey Jondee,
we figured out the problem it was that the lines were hooked up incorrectly the oil cooler wasn't blocked, we switched the lines around and now seems to be fine, but I still wonder why the temps get high because the 4age doesn't come with an oil cooler as standard beats me.

Thanks for that diagram because of the way my oil cooler is designed its hard to mount it anyway beside in the bottom position, but now it seems to cool fine lets see what happens, otherwise Ill try and get a smaller cooler that can be mounted either top r sideways
thanks for your support

Re: 4age 20v high oil temps

Posted: Sun Nov 26, 2017 12:14 am
by GZE_RA21
Sultan, I've read some people have issues with the VVT engagement on 20v engines with the reduction in oil pressure from an oil cooler, have you noticed any problems like that? Also, is your 20v a silvertop or blacktop?

Re: 4age 20v high oil temps

Posted: Sun Nov 26, 2017 1:06 am
by Sultan
Hey, I havent noticed any oil pressure issues, im using a pressure up kit and ported oil pump though, my engine is the blacktop and im running cam gears so VVT is disabled anyway.

Re: 4age 20v high oil temps

Posted: Wed Dec 06, 2017 6:25 pm
by mad_86

Jondee is 100% correct if the inlet and outlet for oil cooler are facing down , it is installed incorrect and you will have trapped air in the cooler and you will not get the max cooling from your oil cooler.

It is best to have it in either facing up or side