My oil cooler is cool

[Motorhome]

Hi,
my Rv class A has been converted by a previous owner from 454 to 6.2.
When I drive the rig my oil temp is beetween 175 to 210 degrees depending of speed etc.
I have an oil cooler which never gets hot, 80 degrees tops. I have checked the lines and cooler and there is no clogging.
In the service manual, GM original, there is two overflow valves described in the text, one for the cooler and one for the filter, but I can only find the one in the base of the oil filter.
Any hints for me to fix the problem?
Nils, Sweden

[john8662]

There isn't one in the cooler, well, for 6.2 application, don't know about 454.

There are two valves though, both of them are located in the block above the oil filter. One is easily visable, the other is underneath the solid plug (that has a little hole in it), it's possible that it's stuck. Although I've not measured the oil temperature on a 6.2 before, and certainly not at the cooler, but this is something that I'd like to find out.

I'll do some checking...

J

[Motorhome]

Thanks,
I have a plug with a little hole in it in the oil filter socket, to the right of the red "P" in my illustration below. Is that the one you are talking about?

Rgds
Nils

1345

[Hubert]

Yeah, I believe so. The oil flows from the pump to the cooler then to the filter head. The outside area is the entrance to the filter and clean oil goes up the knipple to the oil galleries. I think the hole allows oil pressure to build on the back side of the oil cooler bypass so it is a biased balanced differential valve.

Not sure about that. But it makes sense to my understanding of it. The valves are little dinky things with light springs. For reference it only takes something like 17 or 19 psi to open the oil filter bypass on initial flow. But then I think it too creates a biased balance differential valve so that it should only open with significant blockage of the oil filter.

The cooler bypass is suppose to protect the cooler and lines from cold start thick oil not wanting to flow and the oil pump stressing the cooler (and suspect to allow quick oil flow to the bearing on cold start).