High oil pressure and oil loss - BMC 1.5

[RLWP]

Which is an oil filter - so that's OK: http://www.ebay.co.uk/itm/48140087-Reisse-Oil-Filter-AUDI-60-/121432909438

 

 

Richard

Edited December 7, 2014 by RLWP

[jhodgski]

Some bad news, but not sure how bad.

 

With reference to Richard's diagrams, whilst checking all the red areas were clear, I took out this part - https://db.tt/ewn1gzMi (is this the oil jet?) - and then put it back in and ran the engine for a few minutes.

 

After turning the engine off, I then removed it again, but found it nearly all sheared off somehow. It's now lost in the engine somewhere - doesn't appear to be in its hole. Am totally at a loss what to do about that (???).

 

Apart from that, I discovered that all the red areas on Richard's diagrams have no blockages.

 

And I am left wondering about the gauge again because it shows 5 psi when there is definitely no pressure around the sender, and the gauge goes to zero once you remove the sender wire then put it back on.

[jhodgski]

And any ideas why it may have sheared?

 

I've just taken the same part out of my old engine and it came out very easily and also went back in very easily.

 

Both seemed pretty clear, except I did noticed a bit of thread (thread sealant?) stuck in the new one.

 

...so maybe I was screwing the new one out of a load of junk that shouldn't be there, and screwing it back into that junk caused it to shear??

 

Also, not 100% sure if this part (ie, the oil jet?) is on Richard's red route, but if it is, the opening seemed to be blocked when I blew air through another nearby red opening.

[Tony Brooks]

That is or was the oil jet, there is another hexagon a little above that oen and fitted horizontally. That's the strainer that is worth having a look at.

 

I have never had one of those jets snap off but I have had several of the strainers break, both the brass wire gauze and the punched galvanised mild steel types.

[jhodgski]

I have a replacement oil jet (of my old engine), but how much do I need to worry if I can't locate / fish out the old snapped one?

 

Before putting the replacement one in, might a couple of turns on the engine help force the snapped one out - or could that make matters worse?

[jhodgski]

What is the oil jet for, anyway?

[Tony Brooks]

What is the oil jet for, anyway?

 

Post 43 answers that question.

 

I can see no reason other than ham fistedness for it to snap unless something like rag is whirling about in the engine (very, very unlikely).

 

I doubt spinning the engine with the jet holder out will do any harm apart from producing a lot of oil to clear up but I do not think it will do anything to shift the broken piece.

 

I have never taken much notice of that jet other than to make sure it is clean so I have no idea what will have happened to the broken bit. I suspect it may no be in the sump.

[Tony Brooks]

And any ideas why it may have sheared?

 

I've just taken the same part out of my old engine and it came out very easily and also went back in very easily.

 

Both seemed pretty clear, except I did noticed a bit of thread (thread sealant?) stuck in the new one.

 

...so maybe I was screwing the new one out of a load of junk that shouldn't be there, and screwing it back into that junk caused it to shear??

 

Also, not 100% sure if this part (ie, the oil jet?) is on Richard's red route, but if it is, the opening seemed to be blocked when I blew air through another nearby red opening.

 

 

You are the one with the engine, Richard and myself are working from experience and memory. We have no way of being able to inspect your engine.

 

TBH I am getting a little fed up with this. Has the filter been substituted? Has the spin on adaptor plate been removed and inspected to ensure that is not causing the problem. Has the oil jet strainer been removed and checked? Is the OP willing and capable of remove the sump and oil pump so the oil ways can be blown through starting at the oil pump strainer and then moving through the system?

[RLWP]

Let's see if we can summarise where we are

 

• You definitely have high pressure (we have checked the gauge by removing the sender)
• You definitely have an unexpected residual high pressure - this is highly unusual and rings alarm bells for me
• The oil filter is the right one
• The pressure relief valve is in acceptable condition
• you have a broken off drive shaft oil jet oil jet in the engine somewhere

What can you do with the engine in the boat?

 

• Inspect filter, relief valve, drive gear filter and oil jet
• investigate oil jet hole to see if the missing part can fall clear
• remove spin-on filter bracket to see if the gasket is OK

There may be one or two more things, I'm running short of ideas. I would say that if this was my engine, I'd be very wary of running it. High pressure is very unusual, residual pressure even more so. I can imagine things that cause high pressure, like something to do with the relief valve, which can be fixed from the outside. The residual pressure one is a bit of a mystery and more worrying for me.

 

You are getting very close to doing some serious mechanicing - unless you miraculously happen to find some peculiar problem in something bolted on. You are certainly way outside the normal territory of BMC problems now

 

Richard

[MtB]

 

You are getting very close to doing some serious mechanicing - unless you miraculously happen to find some peculiar problem in something bolted on. You are certainly way outside the normal territory of BMC problems now

 

Richard

 

 

I note the OP is still getting anomalous readings from the pressure gauge according to post 52.

 

I'm just concerned that the serious mechanicing (love the term) will, after a load of effort, prove the engine is mechanically good. This will finally force the testing of the supposedly high oil pressure using a different gauge, and possibly show the oil pressure was correct all along.

 

One helluvalot of work to find out it's dodgy gauge. In my line of business, anomalous gauge readings are quite often found to be a faulty gauge. so the first thing to do is rule out the gauge by measuring the parameter with completely different equipment.

 

MtB

[Tony Brooks]

 

 

I note the OP is still getting anomalous readings from the pressure gauge according to post 52.

 

I'm just concerned that the serious mechanicing (love the term) will, after a load of effort, prove the engine is mechanically good. This will finally force the testing of the supposedly high oil pressure using a different gauge, and possibly show the oil pressure was correct all along.

 

One helluvalot of work to find out it's dodgy gauge. In my line of business, anomalous gauge readings are quite often found to be a faulty gauge. so the first thing to do is rule out the gauge by measuring the parameter with completely different equipment.

 

MtB

 

I think that we all agree with that bit I get the impression the OP does not wish to spend any money buying or hiring a mechanical gauge.

 

Seeing the spin on filter is an after market modification I would want to make sure the adaptor has been fitted correctly and come to that designed and manufactured correctly.

[RLWP]

Seeing the spin on filter is an after market modification I would want to make sure the adaptor has been fitted correctly and come to that designed and manufactured correctly.

 

And hasn't been stuck on with excessive quantities of sealant

 

Richard

[Tony Brooks]

 

And hasn't been stuck on with excessive quantities of sealant

 

Richard

 

 

That's one part of what I meant by "fitted correctly".

[RLWP]

 

 

That's one part of what I meant by "fitted correctly".

 

I hate that stuff

 

Richard

[jhodgski]

Thanks for the replies. I've done the following today:

 

1. Replaced the oil filter + boss with the ones off my old engine. (Gasket was ok.) Result: still high oil pressure.

 

2. Oil strainer removed and checked. It was pretty much clear - just a little bit of fibre on it which may have been from when I cleaned it with a cloth previously.

 

3. Ran the engine for a couple of seconds with the oil jet hexagon removed (to try and expel the blockage / broken oil jet piece). The oil that came out looked a bit creamy - in case that is indicative of anything. When I put the hexagon back on and ran the engine, the oil pressure seemed to have dropped a little bit - though not sure if that was due to losing a bit of oil.

 

4. Tried a new gauge and sender. This pair was 100 psi max, whereas the previous pair was 80 psi max. This read just below 60 psi when the engine was at low revs (and out of gear). I am more trusting of this new pair because (unlike the previous pair) the needle returned to zero when I stopped the engine (so confirmation of no residual pressure).

 

When I ran the engine, I hear the odd pinging noise when it's running - which I presume is the broken off oil jet in the sump being thrown around.

 

After the engine stops, I hear quite a lot of slurping noise from inside the engine. It wasn't a familiar sound, so could that suggest anything?

 

Re the previous posts, can someone confirm what the spin on adapter plate is, so I can check that?

 

And does the engine need to be taken out in order to remove the sump and oil pump?

 

And where is the drive gear filter?

 

Many thanks!

James

[jake_crew]

Thanks for the replies. I've done the following today:

 

When I ran the engine, I hear the odd pinging noise when it's running - which I presume is the broken off oil jet in the sump being thrown around.

 

After the engine stops, I hear quite a lot of slurping noise from inside the engine. It wasn't a familiar sound, so could that suggest anything?

 

I'd expect a small object to just drop in the sump and disappear - I assume its not dry sumped ?

 

Are you happy that the oil level is correct and not over-filled. Are you sure you have the correct dip-stick ? (Ford car ones are available in a range of lengths LOL)

[Tony Brooks]

If you have a spin on oil filter as shown in the photo you publishes a while back then it is not a standard BMC 1.5 filter.Look at the schematic. The standard 1.5 filter uses a replaceable filter in a metal bowl/can. This means your engine has been modified to accept a spin on filter. This is done by bolting some sort of adaptor in place of the standard filter head. I have seen several designs for these so can not be certain about what yours looks like.

[jhodgski]

Hiya Jake,

 

What does dry sumped mean?

 

The part the snapped off wasn't so small. It's the missing part from this photo: https://db.tt/xK2aIwln .

 

Good point about the dipstick - I will check.

 

Hiya Tony, Up until today it was using the spin on filter. Today I changed the whole oil filter assembly to the standard filter in a can. It didn't affect the oil pressure.

[boathunter]

Do these engine just have the one PRV?

The engines I work on (I'm no expert) also have an almost identical pressure control valve at the far end or the galleries from the pump to maintain a steady pressure at the bearings.

[jake_crew]

Hiya Jake,

 

What does dry sumped mean?

 

 

Dry sumping is where the oil is stored in a separate tank and pumped to the engine at high pressure.

 

Oil in the bottom of the crank case is cleared by a scavenge pump back to the tank.

 

The system is used in aerobatic aircraft, lumpy water or any other situ where the "sump" is not always below the roatating parts.

[jhodgski]

I have now checked there is no blockage all the way from the oil pump to the output of the oil filter.

 

I have bought an air compressor and have forced air through the the oil filter outlet hole on the engine (obviously with the oil filter removed). When I did this (at 75 psi), I could feel the warm air coming back up through the oil filler cap (I'd taken that off as well).

 

So this makes me believe there is no blockage. Does anyone agree or disagree?

 

But, in any case, if I have high oil pressure (regardless of the cause), why is the pressure release valve (PRV) not letting the excess pressure escape? I have also tried a different PRV so I'm considering (again) whether I really do have high oil pressure?!...

 

I'm going to try some other oil shortly (a 5W-30 semi-synthetic) instead of the Morris Supreme 30 I currently have in to see how much of a difference that makes. (Engine currently idling between 60 and 80 psi, according to the new gauge and sender.)

 

Does anyone have any ideas or suggestions in the meantime?

[jhodgski]

I noticed, yesterday, the oil pressure needle bouncing between approx 40 and 60 psi.

 

I then found this thread - http://www.canalworld.net/forums/index.php?showtopic=22840 - which mentions it is indicative of the PRV working correctly.

 

I also read in the same thread that high oil pressures in BMCs are not that uncommon.

 

I'm left wondering if I really do have a problem? Or, considering this engine seems to have been really well maintained (eg, Calcutt gave it a full service only a couple of years ago), could the high oil pressure be representing an engine that is actually just in really good condition??

Edited January 25, 2015 by jhodgski