Mann-Provent install question (experts, chime in please)

dgeist · **Posted:** Fri Apr 27, 2007 9:18 am

While we're talking about provent filters, I'll drop a question which has been asked before, but never really answered:

Why does no-one seem to be connecting the drain line back to the oil sump as the manufacturer describes?

Since the "nasty stuff" is coming out of the crank case anyway and the provent filter is designed to drain back into the oil system, why not let the oil filter do its job? As I see it, you're pretty much going to have to connect the drain line below the level of the provent somehow since there's no negative pressure anywhere that'll draw the drain fluid uphill. After looking over the manual, I found two options:
1) make a stand-off plate for the oil cooler (mounted just behind and below the water pump on the side of the block) with a barbed nipple to connect the drain line or
2) put a "T" on the pan drain before your fumoto valve and connect the drain to that
3) profit (no, seriously, any other suggestions?)

Either way, I think you'd need to use the check valve so the oil pressure doesn't force the column back up into the filter (fluid dynamics, yesno?) At shutdown, oil in the drain would open the check valve and it would seek the level of the fluid in the sump. If you did it this way, it's a closed self-draining system that doesn't need servicing and doesn't have the potential to have water infiltration from unsealed hoses down low in the engine bay. Has anyone thought of/tried to implement this?

Dan

wenied · **Joined:** Wed Dec 21, 2005 4:01 pm **Posts:** 107

there's always water in the oil i drain from my provent....no way i'll let that back in the oil pan,

dgeist · **Posted:** Fri Apr 27, 2007 9:36 am

wenied wrote:

there's always water in the oil i drain from my provent....no way i'll let that back in the oil pan,

How much and do you know if that is normal or not (i.e. small percentages being introduced by vapor in the intake, etc)? Obviously, no one wants water in the oil system in any significant amount, but I would guess that it's designed to handle SOME. Where are the combustion engineers when you need them?

onthehunt · **Posted:** Sun Apr 29, 2007 10:37 pm

Very normal. Condensation from heating and cooling of engine. All engines do it. That's why it's important to bring an engine up to full operating temps when you drive. It evaporates the water and fuel in the oil. That's why city/short trips lower your oil change intervals.

dgeist · **Posted:** Sun Apr 29, 2007 10:46 pm

onthehunt wrote:

Very normal. Condensation from heating and cooling of engine. All engines do it. That's why it's important to bring an engine up to full operating temps when you drive. It evaporates the water and fuel in the oil. That's why city/short trips lower your oil change intervals.

So, with that said, do folks think that putting the drain from the filter back into the oil sump like the instructions say would be a reasonable thing to do?

Goglio704 · **Posted:** Sun Apr 29, 2007 11:57 pm

I don't think there would be anything wrong with it, but my question is what would it help? The only advantage I can see is that you would recapture some oil which would otherwise be lost.

dgeist · **Posted:** Mon Apr 30, 2007 10:01 am

Goglio704 wrote:

I don't think there would be anything wrong with it, but my question is what would it help? The only advantage I can see is that you would recapture some oil which would otherwise be lost.

My concerns with what others have done is just a paranoia thing, having open lines in the lower part of the engine bay, even going into a capture bottle. I guess part of it was just engineering a beter solution to the problem (and since a better factory filter WOULD HAVE drained the excess oil back into the case). Frankly, I thought connecting the drain to the back side of a fumoto at the bottom of the pan was a rather cool idea, but I suppose in the long run, it's not really a KISS solution. Mostly, I just wanted someone with some diesel/engine tech experience to chime in with the "holy grail" of comments that makes everything clearer and make my decision for me

Dan

Mann-Provent install question (experts, chime in please)

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