Great pics of something which has been suggested on another forum as the possible cause of problems I'm having. My truck shows no pressure at idle on the gauge when it's warm, causing the HPOP to gradually drop and the motor to die. Otherwise, no other symptoms. I don't get it though. Surely if the valve was missing, oil would bypass the filter and reach the rest of the engine and the HPOP res more easily, albeit unfiltered. The oil and filter are new, by the way. Any comments to confirm or alternative suggestions before I drop another batch of expensive lubricant out of the motor?

 

You need to check pressure in the low pressure oil system, if it is dropping like is sounds to be with the HPOP starving you will most likely need a new LPOP.

 

WOW, old thread.
I agree with what Amiller said. There's several stories of worn out LPOP causing problems.
The other thing that sticks in my mind is the possibility that one or more of the piston cooling jets have come off inside the oil pan and a lot of oil pressure is bleeding off there.

 

Yeah, sorry it's such an old thread. Found the forum by searching for the problem and this is what the search engine threw up. It sounds like I'm in for big money! Craning an engine out and back in over here is £1,000+ (about $2000), without any other work. Just finding someone prepared to take it on is hard enough. There is no dealer support and no spares over here, so I'm clutching at any straw to avoid pulling the motor.

 

That's a lot of money!
Are you in Great Britain somewhere?

 

Yep, Hertford, the place Hartford Conn. was named after. It's founder lived here.

Tiny Streets, 600 year old houses. You can imagine how rare a truck the size of an F250 longbed is!

 

Very cool, not only do we get great info on the site, we get a free history lesson too. How did you come to get an F-250 over there? I wouldn't think it was a common item?

 

Rare as hens teeth. Part of the reason being that US vehicles don't conform to safety standards anywhere else but the US, without modification and fuel is $12 per gallon. This one was shipped from Texas in the middle of Katrina. It's been sulking ever since.

 

The LPOP is about 70 bucks here and is not that hard of a job.....no motor pulling needed. Several of our sponsors sell them and shipping would probably be cheaper than getting it across the pond.

PM me your email and I'll send you a pdf of the procedure.

 

Dan, today i was starting to remove the oil pan on our 95 powerstroke, and the bypass is gone, it looks just like the second picture with the open hole. Will it hurt it to run like this, or could i just get the seperate parts?

 

Thanks to amiller93 I now have a pdf in front of me which, I think, makes sense of it all. Running without the valve will reduce both the effectiveness of filtering and oil pressure, as it returns oil to the sump. This will leave the other curcuit from the LPOP, feeding to the HPOP reservoir, at a lower pressure as most of the volume of oil from the LPOP will take the easier route back via the filter housing. I would say that running without the valve is not advisable. I shall be checking mine, before resorting to replacing the LPOP.

 

In theory, it shouldn't hurt the engine - that much.
I've worked on VW air cooled engines that have for a filter a simple course screen and they go for 200,000 miles before they get opened up. The apperance of the bearings is sort of speckled, and all were worn down to the copper. The flip side to that is the later style Porche engines with the oil filter and 200,000 miles were worn down to the copper as well, but the bearings were smoother looking.
So to answer your question, I don't really know if it will truly shorten the life of your engine.
However, considering that the injectors have some pretty small passages with the potential of getting clogged with unfiltered debris, I would be more worried about them having to swallow unfiltered oil than the crankshaft.
Bottom line: you need to get that fixed, it's much better all around. You may have to buy the whole flange assembly to obtain the parts, or to just eliminate the reason that the c-clip fell out of it's place. I suspect that the little groove where it was seated is no longer there. C-clips DO NOT come out on thier own. Some outside force or failure is always the cause.


There are two bypass valves for the oiling system. One is pressure control and yes that one dumps back into the sump and is mounted in the oil pump itself.
The other one in the filter flange, to the best of my knowledge, simply routes around the filter and dumps into the passage that continues on to the engine: bearing, HPOP, etc. None of that oil gets returned to the sump until it has passed through some engine component. Your oil pressure concernes are not caused by this.

 

Need to correct a small detail.
The oil pressure regulator, in most cases, does not vent directly back to the sump, but simply opens to a port in the oil pickup passage where it is recirculated back into the oil pump. The excess oil simply goes around in a circle within the oil pump.

 

Hmmm, it looks like I'm no futher on. Trial and error method of diagnosis ahead. I so hate that.

 

Kwik, I am repairing a leaking oil cooler. I have the ends free but am unable to pull the cooler out due to clearance with the engine/frame. How can I lift the engine without lifting from the oil pan? A bottle jack on the engine mount? Plus 3 parts came out of the rear/oil filter housing. The spring I see above and 2 hollw cylinders, one fits into the other. How does it all go back together because I don't think they were supposed to come out.