Does 10psi/1000 rpm apply to light diesel engines

[Silk]

I wouldn't worry about oil pressure with a 4JB1,just change the oil at 5,000km and oil filter at 10,000km - the bottom end will last for a long time with that regime.They have a dual element oil filter - full flow and by pass,use a good brand and change at 10,000km.Being in NZ it's unlikely to still have the EGR connected,but if it is then get rid of it.EGR problems are more common on 4JB1's than other Japanese diesels.Reco your injectors and have the injection timing checked with a DTI.

What kills these Japanese diesels is overheating - they will crack the cyl head if cooked.Have the radiator rod cleaned,if it has never been done before it is sure to have some blockage,and replace the thermostat.

 

[Paulus]

I'm well used to the arguing that happens in forums. What Dr Haas writes has a ring of truth though because it explains why oil makers are going for lower cold viscosities.

To me, common sense is an important tool. We can't all be white-coated scientists in Mobil laboratories but we can try and understand technical subjects. I'd guess that oil pressures in diesels are higher to cope with the bigger internal forces, remembering what Haas says about flow being an important factor.

Silk - Deane - good to meet a fellow Kiwi here. There is no EGR, the cab and chassis was imported new from Japan.

I generally use a Ryco oil filter. Injectors were done about three years ago. I've replaced the IP top cover gasket (low sulphur fuel leak) but another leak has developed somewhere and it's in need of a full service.

It's only had one instance of overheating that I know of - caught it myself - there's a slow leak around the water pump o-ring - but there's also a lot of crud in the system so your point about the radiator is noted. Replaced thermostat couple of years ago too.

What do you guys think of this? Yesterday in the local Repco a staff member told me about how important it is to use thicker oil and that's why he has 60 grade in his motor. He even had a piece of paper with a graph on it showing how 60-grade stays thicker at operating temperature.

This is where his information comes from http://www.penriteoil.com.au/index.php.

I suppose everyone has an angle.

 

[dnewton3]

Originally Posted By: Paulus
... He even had a piece of paper with a graph on it showing how 60-grade stays thicker at operating temperature.



Thick is good, but not too thick.
Thin is good, but not too thin.

60 grade? Yikes!
I guess it depends upon the OEM spec's and classification.

 

[Jim Allen]

It all comes back to this:

"As thin as possible, as thick as necessary."

It's all about oil temp.

 

[A_Harman]

My .02 is to forget you ever heard of the "10psi/1000rpm" rule. That was made up probably 70 years ago as a rule of thumb to assure feeding of oil to rod bearings in lightly loaded engines. A great reason I can think of to ignore it on modern diesel engines is the need to provide adequate oil pressure to piston cooling nozzles when you are operating the engine at 1600 rpm at max load. 16psi just won't do it for cooling the pistons at that condition.