11 replies to this topic

[Lennyliverpool]

ok my oil pressure has always been good - 60 sat start up dropping to 45-50 during normal driving

i have had to had to change my driving route - its now stop start for 40 mins through town with many traffic lights etc etc

 

now at idle my oil light flashes/stays on till i rev/keep the engine up to around 2/3k

(the gauge will be around 5/10)

once moving the gauge does move back up to around 40 

 

i use the correct oil and its full

car does drive great

 

is this anything to worry about?

lenny

[Stevie W]

Hi Lenny,

 

That's too low an oil pressure on tick-over with the engine warm. 15psi is about the safe minimum on tick-over with a hot engine. 

Once moving with the engine speed around 3000rpm, you should see a good 60psi

How many miles has your engine done?

 

Cheers, Steve.

[Lennyliverpool]

difficult to tell

in my ownership of 3 yrs about 6k

a few months ago and it was set up on a rolling road so runs 95bhp and always drives good

 

i am guessing its been around the block once - just wondering why when very warm the oil levels drop

perhaps the revs need adjusting a little higher to say 1k?

 

is there some sort of pressure valve that can be adjusted?

[nicklouse]

Nothing you can adjust as the pressure is created and maintained by the pump and bearings.

What is the oil you use?

[Lennyliverpool]

20/50 from Halfords

[Dusky]

Tried cleaning the relief valve?

[Stevie W]

Dusky has a good point. The pressure relief valve might very well be stuck partially open, preventing the oil pump generating pressure against it. Would be worth removing it and inspecting the "bullet" on the end of the valve spring. These can get very scratched/scuffed from particles in the oil. Check the valve seat as well. 

 

Cheers, Steve.

[Cooperman]

Very hard to diagnose whether or not there is a problem, or even a potential problem.

It could be one of a number of factors:

 

A pressure relief valve not closing properly.

Tick-over too slow.

High-mileage main and/or big end bearing shells. Just a factor of age and mileage

Worn oil pump.

Oil getting a bit too hot and thinning too much, especially in heavy traffic.

 

The choices might be:

 

Remove the pressure relief valve plunger and thoroughly clean it and clean the plunger seat.

Set tick-over speed to between 800 & 900 rpm.

Try a better quality oil. Valvoline VR1 is really about the best you can get.

Remove the engine and fit new bearings and oil pump (big job, but will identify and bearing or pump problem.

Fit a 10-row oil cooler, check engine temperature and if possible check oil temp (not easy). An oil cooler, though, might keep the oil too cool, so although the pressure may stay higher, the oil will be too cold to work at its best.

[Lennyliverpool]

Thanks for the comments - i plan to do these next!

Remove the pressure relief valve plunger and thoroughly clean it and clean the plunger seat. - over the weekend

Set tick-over speed to between 800 & 900 rpm.- done, its actually around 900/1000

Try a better quality oil. Valvoline VR1 is really about the best you can get. - will source some - will also change oil once i get relief valve done

Remove the engine and fit new bearings and oil pump (big job, but will identify and bearing or pump problem.- hopefully not yet!!

Fit a 10-row oil cooler, check engine temperature and if possible check oil temp (not easy). An oil cooler, though, might keep the oil too cool, so although the pressure may stay higher, the oil will be too cold to work at its best.-must say thought about an oil cooler before as its only when engine is really hot does the oil pressure become an issue

Engine Temp always just below halfway so seems ok

 

cheers

Lenny

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[carbon]

Lenny,

 

Agree with above comments about checking the pressure relief valve is sealing OK. But sounds like it is since using the car in stop-start traffic that low pressure has been an issue, so there may not have been any recent change to engine condition?

 

Halfords 20/50 is what I use, this holds oil pressure well without an oil cooler in traffic with my 1293. I would advise against using oil cooler unless you have fitted a sumpguard - this can restrict airflow over the gearbox fins and cook it up nicely as I have found out in the past. But oil overheating with sumpguard fitted was only an issue on long runs at motorway speeds.

 

How many miles has your oil done? It does thin out after a few 1000 miles.

Edited by carbon, 11 November 2015 - 05:54 PM.

[Lennyliverpool]

Agree 20/50 from Halfords works or used to work fine in my 1330

Oil was last changed in June - i would have done around 1k in miles now - so will change the oil/relief valve as a starter

 

Have had no issues till my lad came back from uni and decided to work across town! so getting back during the rush hour and taking 40 mins seems

to have uncovered an issue....

 

increased the revs to just above 1k which helped somewhat as the oil light only started to flicker towards the end of the journey

 

also i notice the its getting harder to find 1st/2nd gear right at the end of the journey.....which may not be connected???

 

 

ho hum

[carbon]

Lenny,

 

Is it fitted with heavier clutch spring? Orange?

 

Reason for asking is I did have similar low idle pressure on 1300GT quite few years back. Turned out the crank thrust washers were really badly worn. Not sure if this was directly related to oil pressure, but condition of the crank and shells was otherwise pretty good.