Jump to content

Loss of oil pressure when hot


Berty

Recommended Posts

Pett,

 My comments about the 20W50 oil was concerning the short life of the Comma oil. 2000 miles is not very good.  Change one thing at a time methodology I guess. Only heard good things about Castrol GTX 20W50.

I only use or recommend thinner oils as everybody knows.

Gremlins? Yep.

Cheers.

Iain.

  • Like 1
Link to comment
Share on other sites

  • 4 weeks later...

The Jury is in. It's taken longer than expected to get to fix it (mainly weather!).

To recap I had 30-35psi when cold on idle and 0psi on hot idle. Under load it was about 40-45psi and the oil light never came on once the engine was started.

I assembled the bits I thought I would need and...

Changed the oil pressure switch. I wasn't really expecting this to do anything but it was quick and cheap. Sure enough the oil light still didn't come on when the gauge was reading 0psi, but I wanted to make sure.

Changed the oil pressure relief valve. I replaced all of it as again, it's quite cheap. I went for the upgraded spring but must admit I'm struggling to find out at what pressure this will actually kick in.

Oil pressure now 60-65 at cold and under load, but still only 8-10 at hot tick over.

Stuck a different gauge on and now 70 psi under load and 25 psi at hot tick over. Looking good.

Tested the gauges using a compressor - not the most accurate of tests, but you can see the difference. My original gauge was OK at higher pressures, but at 25psi was reading 5-10psi. Also the gauge was a bit "sticky".

Ordered and fitted a replacement gauge (the test one was not mine and was not was as graduated). 

Cold tick over 60-65psi

Under load - 65-75psi

Hot tick over 20-25psi

I may stick in some 20/60 oil at next change which may also help.

Thanks for all your suggestions - with your help I think it's sorted relatively cheaply.

But should I be reverting to the standard oil pressure relief spring ??

Link to comment
Share on other sites

there is only one specification made by triumph  that is with  the oil of the day which you need to look in the owners handbook it not quoted in the WSM.

we all recommend  a 20/50   various brands and specs are available  better quality oils give more stable results 

the base spec for all 4 and 6 cyl engines of our model range  is n   40 to 60psi  at 2000 rpm  at running temperature 

if  you meet those results dont mess with any more 

figures at idle   are not critical , there is nothing  specified other than the switch setting of 6-8psi as a low warning   

so time  for peacefull   sleeping

 

  • Like 1
Link to comment
Share on other sites

Congratulations on the fix - if only low oil pressure was always that easy to cure! The only disadvantage I can see against having the higher pressure relief spring is the slightly increased risk of leaks from places like head gasket and oil filter.... 

Link to comment
Share on other sites

I wouldn't be worrying about a 20-60 with those pressures, very acceptable. 

Glad it was just the gauge (and the relief valve) and nothing more serious. The prv change would not have helped if the bearings were very worn, so the engine sounds healthy.

  • Like 1
Link to comment
Share on other sites

That is the correct oil route, Berty, for your car.

The only point I will add, is that quality grade oils such as Millers, Penrite and Classic Oils Heritage have a far better shear factor than cheap supermarket varieties. It is that which ensures the oil remains stable at higher temperatures whilst under stress.

Regards.

Richard.

 

Link to comment
Share on other sites

A slight thread drift here, but what are the best conditions for storing oils. Cool/warm temps, garden shed, garage? I have 3 gallons spare at the moment in the garage which is in the way (all the cupboards/shelves are full as you would expect). I have space in out buildings but am worried that extreme heat/cold might not do it any good over time. I appreciate that in the engine the oil suffers  heat and cold wear and tear, but I wondered about long term storage. Iain/Clive/Richard, over to you.

Link to comment
Share on other sites

I keep all my oil stock in the garage which also includes a large amount for other car clubs.

Ideally a cool environment.

Can you keep the containers on the garage floor tucked out of the way ?? That is the ideal condition.

Regards.

Richard. 

Link to comment
Share on other sites

"A prophet is without honour in his own land"

Quote my post, last page "It just could be the oil pressure relief valve is stuck open, or more open than it should be. "   Berty changes the relief valve and cures the problem.   No thanks, no probs.   But may I have a bonus point please, to bring me just a little nearer to St.Pete?

"Not even close to Pete Lewis" ?   That's hurtful, thanks Mr.Editor.

John

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

JohnD - Apologies. I'm relatively new here. I thought I had profusely thanked everyone that had helped me within the text, but I did not realise there was a separate system to award thanks to individuals.

I have now awarded you your requested thanks.....

Berty

Link to comment
Share on other sites

Berty, don't fret about all those gold stars as stuff. You finding the issue is what really matters.

Of course, Pete (definitely not a saint, thankfully) has accumulated a vast amount of gold stars because he is such a helpful, but more importantly, knowledgeable chap. The rest of us are also-rans

Link to comment
Share on other sites

Thanks, Pete!  No offence, just thought my new byline was a bit unnecessary.  I see Clive gets the same.    OK, it's 'just a bit of fun', but personally, I dislike intensely that giving good advice has been turned into a competiion.     Everyone knows Pete as a generous fount of all Triumph knowledge.   No need to make it a coup-counting contest.

And Berty, no offence taken - you did thank "everybody" and when all have waded in with well-meant advice, what else can you do?

John

  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...