Really Low Oil Pressure

[Project Five-0]

Hello all,

Very recent Stag owner with nothing more than very basic mechanical experience!

Had my '76 Mk2 for 2 months, running beautifully, no over heating, however have recently noticed extremely low oil pressure:

On start up - 30-40
Hot running - 15
Idle - Hovering above zero and oil light coming on!

When I spoke briefly to local mechanic, his advice was to take the engine out to diagnose and rebuild as it is misleading that is runs and sounds so good?

So I am asking for some guidance from the knowledgable - 1. does the engine really need to come out? 2. Possible causes and remedies in situ?

Many thanks in advance and apologies for my ignorance if details are scratchy!

Simon

[V Mad]

I would check to see if there is any problem with the oil filter; there have been problems with filter element gaskets coming off and blocking the oil ways.

Then check the oil pump first before pulling the engine. Remove the pump and inspect to see if anything is clearly the cause of low pressure.

[73stagman]

Agree with Chris. Check the oil pump, filter and relief valve first... Change the oil and filter and preferably use a 20W50 engine oil. (A 15W40 or 50 oil can be used if its known that the engine has recently been overhauled but I would stick with a classic mineral engine oil for these older engines)

I just changed from a well known brand of 15W50 oil to Halfords Classic oil and gained around 10 psi when the oils cold and 5 psi when its hot (My Stag has a Rover V8 so your pressures would look fine in my car!!)

[Project Five-0]

Chris / Neil

Thanks so much for your quick responses. That was my first port of call, oil/filter change. Have been using Halfords Classic, but am going to change to Valvoline. Failed on first attempt as couldn't get the sump plug off!! Ordered the Triumph sump plug spanner, so will have another go at the weekend, hopefully more successfully!!

[stagjim1]

Hi Simon I had the same trouble when I first bought my stag very low oil pressure like the other member have said change filter / oil before you start thinking about
taking your engine out because that a task on its own, good luck hope you get a quick fix.
jim

[Ian F]

Agree with Chris and Neil, but if persists when you have changed oil, it may be worth getting the pressure checked on another gauge? Unlikely that current gauge AND pressure switch are misreading, but any and all checks, especially the pump itself, are worth it before pulling the engine out?

ian F

[djw113uk]

Do you have standard filter or spin on conversion? The spin on kit is quite cheap - was happy for 35,000 miles in my stag, and no issues with dodgy original filters with wrong ends or whatever then too. The spin on unit can be bought almost anywhere too.

On an 1850 we dismantled the pressure relief spring had been rubbing on the bore and was in two pieces as we extracted it. Never seen another one like that, but that is a quick and easy thing to check. Don't go for the uprated spring on a stag through as the 80psi it gave in the 1850 & sprint is a tough too much for the stag.

[Seaking]

Do you have standard filter or spin on conversion? The spin on kit is quite cheap - was happy for 35,000 miles in my stag, and no issues with dodgy original filters with wrong ends or whatever then too. The spin on unit can be bought almost anywhere too.

On an 1850 we dismantled the pressure relief spring had been rubbing on the bore and was in two pieces as we extracted it. Never seen another one like that, but that is a quick and easy thing to check. Don't go for the uprated spring on a stag through as the 80psi it gave in the 1850 & sprint is a tough too much for the stag.

I believe that the uprated spring as you quote is now a standard fit on new county pumps and if you buy a new oil pump you will have to change the spring to the old spring.

[Paul Roberts]

Hate to be an Eeyore, Simon, but I suspect that one, or more, or all of the engine's bearing sets are leaking oil.

Crankshaft main bearings, big-ends, jackshaft, camshafts.

It's not a nice thought but if you do the work and replace them, as required, before it breaks; you will save yourself heart-ache in the long run.

A strong heart is essential - for both you and your Stag.

Have a stiff drink, and then, do some costings. You won't enjoy this bit but it is the answer.

Good luck and I hope I'm wrong.

TBO

[73stagman]

I am not going to disagree with Paul as the pressures stated by the PO are pretty low for a Stag. However in order to diagnose a little bit further an oil change and oil filter and an inspection of the pump is a cheaper option than pulling the engine out and then to bits to discover that there is not much wear to the bearings or the crankshaft but the oil pump is badly worn out.
An oil change and new pump may not fix the oil pressure problem but it might just do enough until further work can be done. The pump then will be good for if the engine does have to be stripped down in the near future.

[Project Five-0]

Thanks guys for your input - much appreciate by a novice!! Also, thanks for the heads-up on the 'worst case scenario' too - potential winter project?

The car's got a standard filter on it, just got GFE147K from RB to replace - what are the benefits of a 'spin on'?

Also, judging by your comments, is it worth replacing the pump at the same time?

[jleyton]

I agree with most of the above and I was in a very similar situation to you about four years ago.

Quite a bit of advice on here recommended pulling the engine however I elected to drop the sump first, knowing that, if this showed up a worn crank then I'd still need to pull the engine. Although I had to drop the front suspension/subframe, when I dropped the sump I found worn shells but the crank looked ok.

New big ends and mains, as well as thrusts for good measure, together with an overhaul of the oil pump, saw good pressure returned and, 15,000 miles later, all seems well.

It wasn't too hard a job and a good result. The only thing I'd mention is that mine did exhibit some big end rumble beforehand - does yours Simon ?

Good luck.

Cheers

Julian

[DJT]

Simon,

You are lucky to be living in the same town as our esteemed President, Lesley Phillips, and her very knowledgeable husband Roger. Their contact details are in the magazine. Roger may be willing to take a look and recommend a solution.

[4x4]

Whatever's wrong - it probably won't be as bad as mine was.
Four out of five main bearing caps fractured (two of the bearing shells had cracked too).
Crank just needed a polish!
You don't want to know what else it needed.

Good luck :-)


Adrian.

[TR5convalescent]

If you need a new pump I suggest you ask on here for recommendations before buying. In the world of TRs oil pumps made from recycled Dinky toys abound. Someone on this forum will know who is supplying decent ones.