91-94 Oil Cooler Flow

[520Talon]

I unfourtunately have a collection of oil coolers that havew seen a little bit of metal in them. I have been looking at it and how it goes with the filter. By looking at the anti flowback flaps it appears that the oil goes through the part that would be contaminated before it goes to the filter and then back down the hollowed bolt back into the motor. IIRC that housing is the first place the oil goes after the pickup and pump. So in theory wouldn't the filter catch anything that would be missed durring a cleanup? If so wouldn't that mean it could reused without much worry (of course cleaned first).

I know throwing it out is a common thing to do and I am just wondering if my thoughts are flawed or not. Those things are hard to come by and a grip at the dealer.

[MustGoFaster]

Well, the oil does come in through the cooler, in the filter then out through the bolt. But there is a bypass valve in the filter, that opens up when the pressure drop across the filter is greater than 17-20 PSI (cold starts mostly)

[520Talon]

I think you might be a little low on your spec, but you are correct on the bypass valve. I have looked at the layout of the peice and it appears that the bypass valve is before the cooler. I am willing to bet it is in the pressure regulator before the cooler. I also don't see any path for the oil to go through in the cooler or return pipe from the filter.

Does anyone have the factory manual with the oil path diagram?

[Jed]

this what you're lookin fer?

[MustGoFaster]

The relief valve and the bypass valve are two different things. The relief valve is set around 78 PSI. This is in the oil filter bracket, before the filter. It dumps back into the oil pan. The bypass valve is internal to the filter and IS actually 13-18 PSID (PSI Differential). (I was just going off the top of my head in my first post, sorry). The bypass valve is, just as it says, a valve the bypasses the filtering medium when the pressure differential across it is too high (13-18 PSID is the spec, see here ) So even though there is a filter after the potentially contaminated cooler, the filter will at times be bypassing oil (meaning the engine is getting unfiltered oil, but dirty oil is better than no oil in most cases)

[520Talon]

Jed - yes that was exactly what I was looking for. Thanks.

Must Go Faster - I had completely forgotten about the valve in the filter. Nice catch. That would be the little bastard that would let the metal past the filter and to the motor. I guess I'm off to find a new oil cooler. Damit. Good info though.

[MustGoFaster]

Your welcome.