19 replies to this topic

[speedwell1]

Well I've decided to bite the bullet, I have a relatively new engine in my car, it's only done about 2000 miles, but I've found that the hot oil pressure is very low, on start up I get 80 psi cold but if driven hard I get around 10 psi when hot at idle and it doesn't ever get above 40 psi if given the beans, I've changed the oil and filter twice using vr1 but it didn't help , I was getting more pressure when I first started using the car but its got progressively worse. I did notice a slight gold mist in the oil on the last change,

I'm going to check everything but do u think my problem is likely to be an out of tolerance oil pump(new when fitted)or bearings

What should I be looking for when checking the main and big end bearings?

Thanks

[the.stroker]

I’d be checking your oil pressure relief cup isnt stuck ( if fitted) in the first instance.

[speedwell1]

Sorry should have said, it's the ball bearing type relief valve and I've checked that, thank you though

[Dusky]

What clearance did you have on the mains to start?
Gold mist after 2k miles and several oil changes isnt really a good sign..

[Steve220]

Sorry should have said, it's the ball bearing type relief valve and I've checked that, thank you though

That won't help.

[Spider]

 

Sorry should have said, it's the ball bearing type relief valve and I've checked that, thank you though

That won't help.

 

 

This maybe the issue, for a variety of reasons. For how easy it is, I'd suggest swapping over to a standard relief valve shuttle and seeing how that goes.

 

If when fitted up with the ball, the spring wasn't shortened, there's a very good chance the oil has been cooked to death.

 

Some more info on the Ball Relief Valve Conversion and some of it's pitfalls here;-

 

http://www.theminifo...huttle-vs-ball/

[speedwell1]

I did shorten the spring, Ill try the plunger first, thanks

[carbon]

+1 for above comments about using ball & spring. I used this many moons ago, gave super-high pressure when cold and ended blowing out the main gallery oil plug on a particularly cold morning. Have used the standard plunger and spring ever since.

 

Gold mist in oil is not good. Before taking engine apart check the crank end float, and once apart carefully inspect the thrust washers and crank thrust faces.

[russo]

May sound silly, but standard main bearings weren't fitted to maybe 10 thou undersize journals. Just a thought.

[Magneto]

My engine does exactly the same thing, it was worse before I put a new shuttle in and cleaned everything up but in the end the results were almost the same - when cold it holds a nice steady 70psi, when hot after running on the highway a while it's down to about 40 psi at 3K rpm, and at idle somewhere around 20.

 

The interesting thing is if I let it cool for 10 min I'm right back at 70 psi....for a while.

 

I wish I had  an oil cooler, just to test if keeping the oil cool would make a significant difference.

 

In the end I think I just have worn bearings......no idea whether this engine has ever been open or not.

[Dusky]

May sound silly, but standard main bearings weren't fitted to maybe 10 thou undersize journals. Just a thought.

Its a lot more fun when that happens. 0 oil pressure and vibrations that crack conrods etc. Dont ask me how I know ?

[Bat]

My engine does exactly the same thing, it was worse before I put a new shuttle in and cleaned everything up but in the end the results were almost the same - when cold it holds a nice steady 70psi, when hot after running on the highway a while it's down to about 40 psi at 3K rpm, and at idle somewhere around 20.

 

The interesting thing is if I let it cool for 10 min I'm right back at 70 psi....for a while.

 

I wish I had  an oil cooler, just to test if keeping the oil cool would make a significant difference.

 

In the end I think I just have worn bearings......no idea whether this engine has ever been open or not.

Hi,

If you've got 20 psi on hot idle I'd say there's nothing much to worry about at the moment.

Just use a good quality 20w50 and change regularly.

Cheers 

[RooBoonix]

On my fresh rebuild I get 30-35psi hot idle after a motorway run using Minispares 20w50.

I was getting 15-20psi hot idle before the rebuild (90k miles).

[speedwell1]

Thanks for all your suggestions, I'll try the plunger with an oil change and see how I get on

[ACDodd]

Factory oil pressure 15psi idle and 60psi hot.
I have a fresh 1380 here that gets 20psi hot. Its fine

Ac

Edited by ACDodd, 12 September 2018 - 07:13 AM.