Perkins D3.152 as fitted to MF135 - oil pressure

[Richardf59]

Hi
I hope it isok to post here, I have bought a D3.152 to put into a canal boat in the uk. It has been rebuilt with new pistons, liners, crank regrind, bearings, oil pump etc.
The problem that I have is that after a hard run of around an hour, the idle oil pressure drops to 15psi - it is 60psi when cold. Temps are fine and the engine has been out of the boat once ( no easy job) and another new Perkins oil pump fitted, but no better.
Could anyone advise me what the hot idle oil pressure should be, the manual says 30psi when running fast, but I can't find any mention of idle pressure anywhere.
Would very much appreciatevany advice from owners of this engine.
Thanks
Richard

 

[Agvg]

What type of oil are you using?

 

[BigBoyinMS]

I may be wrong but I seem to remember 15 psi wasn't abnormal on mine when it was at operating temp and idling.

 

[Richardf59]

What type of oil are you using?

Hi

I have tried 10W40 and a straight 30.

Someone else has suggested a 20W50, but haven't tried it yet

Thanks for your replies

Richard

 

[Agvg]

Hi

I have tried 10W40 and a straight 30.

Someone else has suggested a 20W50, but haven't tried it yet

15psi is ca 1 bar and that should be OK, how low on rpm do you idle it? They can go very low.

What are you measuring the pressure with? Tryed different gauges?

 

[Richardf59]

15psi is ca 1 bar and that should be OK, how low on rpm do you idle it? They can go very low.

What are you measuring the pressure with? Tryed different gauges?

We've measured it with a couple of gauges, but both read the same.

I'm afraid that it does not have a rev counter, so impossible to say what the idling speed was.

 

[Agvg]

Does the pressure follow RPM?, does it rise on high idle?

Non of my books has a minimum pressure on this engine but 15 psi should not be to low on idle.

Did you check the clearance on the engine bearings when you replaced the pump?

 

[Richardf59]

Does the pressure follow RPM?, does it rise on high idle?

Non of my books has a minimum pressure on this engine but 15 psi should not be to low on idle.

Did you check the clearance on the engine bearings when you replaced the pump?

It does rise with revs.

All the bearings have been renewed . Big end, mains and cam and the crank reground.

Maybe this is as good as I can expect!

Thanks

Richard

 

[Jerry/MT]

The major reasons for low oil pressure with an engine at operating temperature are worn bearings, worn pump, or stuck open oil pressure relief valve.

Did you do the rebuild work yourself? If you did did you check the bearing clearances with Plastiguage? if you did that and they were within spec than I'd suspect a problem with the pump or the reliief valve in the pump.

 

[Oliver Taylor]

Richardf59
I wonder whether you ever solved your issue satisfactorily. I have a remarkably similar problem, a D3.152 dating back to pre-1992, which I can only guess was taken from an MF135 tractor or generator and marinised for installation into a narrowboat in the UK. We had it for two years when it broke down in March this year and we had to have the engine removed and rebuilt; all bearings, liners and pistons replaced, and new oil pump fitted. In fact it had to come out again almost immediately it was installed, because during the installation something metallic was entrained in through the inlet manifold and smashed up the crown of one of the new pistons. Anyway, when we finally had everything back in order she ran beautifully; from cold the idling oil pressure was about 40-50 psi. However, we have found that an hour or so after getting up to temperature (75 C, constant) the oil pressure gauge can fluctuate rapidly from 10-60 psi, even at normal cruising speeds, often mimicking the tone of the engine (revs fluctuating?), and to maintain good pressure we have to push the revs up higher than normal. At idle and dead slow (tick-over) the pressure reads a constant 20 psi, but I am concerned that this could also be bottoming out on the range and simply a gauge error. The sensor and gauge are electric, so I shall be testing with a hydraulic pressure gauge next week. At normal cruise speeds after some long days (6-8 hours running) the oil pressure fluctuates around 30 psi and above, so the engineer who rebuilt it says it is within normal operating conditions, but this doesn't fill me with confidence for the long term. I use a 15W40 oil and changed the oil and filters after around 50 hours after re-installation. I have no rev counter, just gauges for temperature, oil pressure and battery charge. Any thoughts/suggestions welcome.