4-108 Oil Pressure Drop After Oil Change.

[zeehag]

check all hoses and gaskets and fittings -- we found holes in the pressure lines from engine to remote filter---keep looking---good luck.

oh yes--check your sending unit also and the gauges. i have back up mechanical gauges as well as the electrical ones in cockpit, so if i have problems with one gauge i have backup and safety factor.

[phorvati]

here is a pic of the oil pump and bypass valve. And another one showing the cork gasket for the oil pan. These were taken during disassembly. I could try to take only the oil pan, but putting that cork gasket back and sealing it off so i don't have oil leaks will be hard. I have not had any oil leaks in part b/c I sealed this area very well. I assembled the front and back plates /timing gears and cover after the oil pan was put on.

[zeehag]

my heart stopped at the sight of the beauty of the interior of your engine.... i am drooling in awe.....
remember, these engines do need a small dripping of oil-- they dont run without that---english, you know....
BUT, dropping pressure is not in the rules-must be repaired---
is your oil filter remote or on engine? have you checked everything---what does oil look like--is it clean oil or cafe au'lait? is there more oil in engine after filling(and slightly thinner viscosity) than you placed into it--sometimes is a diesel leakage into oil system--if so--find and fix...

also check the gaskets in oil filter-- is there one there or two--if two--ditch the bad one--- friend had a blow up from that exact thing--

cant get over how gorgeous is your engine....mebbe slight bit of coveting here....

[phorvati]

I'm glad you like it...here are some pics during re-build.

1. No diesel in oil. Oil level is the same, no more, no less then what i had after first 60-70 hours.
2. No oil leaks. I installed a self made remote oil filter which initially leaked. So it took me about a month to trace those down and i am absolutely sure oil is not leaking at hoses, filter, below engine oil pan or any external engine points.
3. No smoke of any kind under load.
4. Small amount of white smoke while idling after long run time.
5. Exhaust water is clean, no diesel in it.

One other thing I did to have hot, hot hot domestic water is:
I plumbed oil cooler so that antifreeze is going through it instead of raw water. I am using the 5/8ID antifreeze line that leads towards hot water tank. Antifreeze leaving the head goes through water side of the oil cooler before entering the hot water tank. Then back to the head where I also have temp sensor.

[gjordan]

You may have just explained what your problem is!!!! If you changed your oil cooler plumbing from raw water to engine fresh water it could be overheating your engine oil. Actually most engine oil coolers are designed to run with the water from the fresh water side of your cooling system, but if your was designed to run with raw water and you changed it it would overheat your oil. That still would not prove why it took so long to discover the problem. The transmission oil cooler usually uses raw water but the engine oil is normally cooled(and heated) from the freshwater side.____another 2 cents worth.____Grant.

[phorvati]

Ive used it this way for about 40 engine hours. These engines don't really need oil cooler in recreational applications. There is section in the manual mentioning this. I ran for a while w/o oil cooler. Then I put it in to help heat domestic hot water. And boy is my water hot.

[DeepFrz]

What is the temp. of your oil when engine is up to normal operating temp?

You are right that most oil coolers use the coolant to help keep oil temp steady and up to proper operating temp.

[donradcliffe]

Originally Posted by phorvati

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Injector pump bearing? You mean the bearing on the IP drive gear. That same gear drives the raw water pump. I don't think that one has a bearing. But if it lets oil out it would just run down inside the timing cover and back in the crankcase. That check can be done w/o lifting the engine, the problem is I can't really run the engine w/o timing cover to see if oil is gushing out.

As you say, it was the bearing on the IP drive gear--the bearing was so worn that way too much oil was flowing through it--no external leakage, but low oil pressure.

[phorvati]

Originally Posted by DeepFrz

What is the temp. of your oil when engine is up to normal operating temp?

You are right that most oil coolers use the coolant to help keep oil temp steady and up to proper operating temp.

So you're saying its better to cool oil with coolant as opposed to raw water?
Original setup on these engines is to have raw water cool oil. I am not sure what my oil temperature is. I am a bit suspicious of my home-made remote oil filter. I am going to take that apart and have a look if there are any oil blockages contributing to decreased oil pressure.

As to running on a hot side: I dove down 2 days ago and found a lot of hard barnacles in the raw water through hull intake. I crushed them with a screw driver as best as I could, and naturally they all got sucked in and completely clogged my raw water strainer. After cleaning that out, my temperature dropped a bit. Now I am at 185F after about 1 hour under full load.

I wonder if the fact I am cooling oil with coolant means that oil is actually heating the coolant temperature. My oil cooler is in the domestic hot water tank circuit. So that part never sees the raw water heat exchanger. Only domestic hot water tank which gets scorching hot very fast so it looses heat transfer ability. Then that hot coolant returns to the head where the temperature sender is. So temperature sender is sensing coolant returning from oil cooler and domestic hot water tank.

[DeepFrz]

Do you have an IR thermal sensor? You can get temps from different parts of the engine and it takes the question out of how hot things are. If your oil is getting hotter than the oil company recommends then you will have to put it back the way it was or run without an oil cooler. However running it the way it is would be preferred IF your oil isn't getting to hot.

[neilpride]

Oil and transmision cooler are cooled by raw water , at least in my 4236, good idea if you goo back to the old setup in the filter and fit a original perkins oil filter and check for any diference in presure.

[phorvati]

So I went back to SAE30, I took out oil cooler new NAPA Gold 1515 (black) oil filter. I inspected remote oil filter hoses, and connectors. No blockage. Pressure is low. I didn't put it under load, but I cant get over 10PSI cold no matter how high I rev it at idle. Warmed up, same story, It drops to abut 5psi.

Next i will take off timing gear cover and have a look at gear bearings. Might even try to crank with timing off to see if there is any substantial oil leaking from gear bearings. Does anyone know if you can take timing cover while oil is in the engine? My engine is tilted back quite a bit. Max installation in the brochure 17deg I measured mine at 15deg.

[Ex-Calif]

As a positive displacement pump oil pressure is directly related to rpm and system restriction. The regulation is simply a pop off valve. Low oil pressure can result from

- Oil pick up blocked or loose - air enters instead of oil
- An internal oil line has come loose or is leaking - your pictures seem to show bolted on oil tubes under the valve cover
- Pop off valve stuck open
- Oil filter restricted, blocked or bypassing - Do you know if you oil filter has a bypass?
- Oil passage restricted
- Failed oil pressure sender
- Gear pump failed
- Oil hiding - Oil hiding occurs when oil is pumped into system and can't drain or return to sump. sump runs out of oil and starts cavitating. This could occur if drain holes from the head are restricted. Oil pools in the head and after shut down drains slowly - Oil pressure will be good at start for a minute or two

The fact that this started after an oil change could be a red herring or could be significant.

Something could have dislodged during the oil change. Lot's of sealant was used (I presume) for pan gasket, front and rear seals etc.

I would remove and check the sender next if not already done so. Most of the troubleshooting for this is going to involve tearing the engine down again and you want to eliminate everything else first.

I would not personally try to run the engine with the timing cover off.

[hpeer]

This may be totally stupid but..........try checking your oil LEVEL.

Maybe top off the oil a bit and see if that effects your pressure.

It may be stupid but is cheap and easy and does no harm.

[phorvati]

Originally Posted by Ex-Calif

The fact that this started after an oil change could be a red herring or could be significant.

Something could have dislodged during the oil change. Lot's of sealant was used (I presume) for pan gasket, front and rear seals etc.

Its a clue, but to what?
Its unlikely that sender or gauge failed after oil change. They are simple to replace so its worth a try.

I Cut open my old oil filter and it doesn't show any metallic crumbs. Although this filter only had about 10 hours on it.
I am pretty sure oil filter is not blocking. I'm on second oil filter/oil change since the problem was detected.
External oil filter lines are clear. At the moment i have oil cooler out of the loop for troubleshooting purposes.

It seems that the fact it happened after oil change would point to to internal stuff. Pickup screen/tubes, pressure relief valve.
If that red gasket material came loose inside the oil pan, pickup screen would have blocked it.

I have put the red gasket material on the external oil filter flange as well. If a piece of that red-gasket material came off, it would have lodged itself somewhere else in the gallery. That would suck.

I'll tee-off the NPT fittings at various places, like before and after filter at the block, and mount 1/8" NPT mechanical gauge.

Westerbeake 40 has an oil hose coming out of the block to a multiport fitting where the sender is attached. It has several 1/8" NPT female ports for various stuff, senders, alarms, etc. This is where I am sensing pressure at the moment.