Can oil flow backwards in the filter?

Joined
Jun 3, 2004
Messages
51
Location
California
The previous owner installed a remote oil filter kit but had the OUTLET from the block hooked up to the OUTLET of the oil filter housing. I had to double check this myself. The engine ran fine. So what happened? Did the oil just flow backwards thru the filter? or was it bypassed?
 

Reelizmpro

Thread starter
Joined
Jun 3, 2004
Messages
51
Location
California
I don't get it. It shouldn't work at all. Perhaps the housing was mislabeled...Going to take another look.
 
Joined
Sep 28, 2002
Messages
39,802
Location
Pottstown, PA
Well, if the filters had no ADBV ..and/or the media just ripped, it could work. If it's supposed to have an ADBV ..and is appearing to work okay ..then I'd suspect that it was spitting rubber chunks out somewhere in the engine. Most remote mounts are setup for Ford filters. There are Chevy remotes ..and many Chevy filters don't have an ADBV ..but it would still be a challenge for it not to bellows the media since it has no external support like it does the other way around against the center tube.
 

Reelizmpro

Thread starter
Joined
Jun 3, 2004
Messages
51
Location
California
I doubled checked and yup the hoses were switched. Outlet to Outlet. My setup uses the Ford style filters. That must be what's happening. I took the system apart to install a thermostat sandwich for the oil cooler and discovered the mix up. What impact do you think this mix up would have on oil pressure?
 
Joined
Sep 28, 2002
Messages
39,802
Location
Pottstown, PA
Well, at this point, nothing. It worked out somehow. You've tested this by running it, correct? If they were switched, there should have been no oil pressure until the ADBV had holes punched in it the size of the inlet holes ...that would then be outlet holes. If you haven't started it up yet, just make sure you've got it right. It's been a while ..so let me think. Yes, it should be like to like. The outlet (exterior biased) port should be to the exterior biased port and centered port to center port. That could be said "outlet to outlet" and "inlet to inlet" if referring to it from the filter's perspective. More accurately stated, Inlet to filter to Inlet to filter and Outlet from filter to outlet from filter.
 
Joined
Nov 6, 2002
Messages
4,844
Location
Saskatchewan
Is the filter bypass valve in the filter or on the engine? If it's on the engine and the filter has an ADBV, it would probably just bypass the filter. If it's on the filter only, I don't see how that setup could work!
 
Joined
Mar 14, 2003
Messages
8,711
Location
Nothern USA
Depends. Most GM products have a bypass in the block. Most others, including my Chevy LUV, have it in the filter. With a bypass in the block, you should have a good flow of unfiltered oil. The bypass in the filter is another one way valve and wouldn't let the oil flow from the filter center to the outside. Now inlets and outlets can become confusing. In a remote, the oil should flow out the outer hole in the engine filter mount to the outer holes in the filter, and back to the engine through the center hole and into the engine through the center hole. Inlet to inlet, and outlet to outlet. Note, GM filters such as PF 47, PF 52, and PF 1177 have ABDV's. the PF 1177 is one of the few that have a bypass too.
 
Last edited:
Joined
Aug 5, 2008
Messages
691
Location
Aridzona
Outlet <-> Outlet and Inlet <-> Inlet may be correct! Don't go 'fixing' the plumbing until you've ascertained the correct flow through the remote filter housing. Ignore the labels and try blowing air (smoke?) into the two housing hoses. See which one supplies the outside of the filter area. (Filtered oil will exit the filter through the central hole.)
 

Reelizmpro

Thread starter
Joined
Jun 3, 2004
Messages
51
Location
California
Well everything is apart so I can visually confirm where the passages go and it was hooked up wrong. Oil comes out of the block thru the small holes on the circumference of the filter and flows back thru the middle hole. Now this is what I'm seeing. The outer hole on the block adapter is oil leaving the engine (labeled outlet). This hose is supposed to go outer hole on the remote filter head (labeled inlet). It was previously connected to the center port of the remote filter head before, so "outlet" to "outlet" isn't correct but I understand what you guys are saying. I think there is some confusion. So, the oil then flows from the circumference inward towards the center and comes back to the engine. In other words, outside port (outlet on block adapter) to outside port (inlet on remote filter head) and inside port (inlet on block adapter) to inside port (outlet on remote filter head). So I need to go "outlet" to "inlet" from block to filter and "outlet" to "inlet" from filter to block. Also, when I took the filter off, I could tell something wasn't right. The center port was filled to the top with oil. Yet when you tap on the filter, it sounded hollow/empty. You know when you tap on a used filter, it has some weight behind it.
 
Last edited:
Joined
Sep 28, 2002
Messages
39,802
Location
Pottstown, PA
The only thing I can imagine is that the whole assembly got compressed enough toward the bottom of the can ..and the ADBV went with it ..allowing flow to just pass across the top of it. That guy got very lucky, imo. Good thing you caught it. \:\!
 

Reelizmpro

Thread starter
Joined
Jun 3, 2004
Messages
51
Location
California
Luckily, the engine seems to be alright. I always had sufficient oil pressure. Good thing too, because it only had 1500 miles on a fresh rebuild + turbo.
 
Joined
Mar 14, 2003
Messages
8,711
Location
Nothern USA
You never said what kind of an engine. A GM, likely you had unfiltered oil flowing through the block bypass to the engine. Others? Maybe the cause of the rebuild. iatrogenic* problems. *iatrogenic (iatro- + Gr. gennan to produce) resulting from the activity of physicians. Originally applied to disorders induced in the patient by autosuggestion based on the physician's examination, manner, or discussion, the term is now applied to any adverse condition in a patient occurring as the result of treatment by a physician or surgeon, especially to infections acquired by the patient during the course of treatment. Cf. nosocomial.
 

Reelizmpro

Thread starter
Joined
Jun 3, 2004
Messages
51
Location
California
It's a 90 BMW 325i M20B25 2.5 liter inline 6. The turbo manifold doesn't leave enough room for the oil filter/housing which is why a relocation kit was used.
 
Top