Oil pressure dropping when hot

Navyreg1970

Navyreg1970

0
I dont think its a huge issue but........

Took the dog from home to work this morning (26 miles)

managed 55mph on the flat before the temp dial started nudging the red so I backed off (early days)

I did however notice that when the engine is hot my oil pressure drops off - i get the warning lamp flicker when i stop at roundabouts etc. This clears as I pull away but warning lamps are there for a reason.

After getting to work I dipped the oil and the level hasnt dropped at all.

Do you just think its a viscosity due to temperature issue?

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just confirming on the gauge its running at hot idle on 2kg/cm2 = 25 psi

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ah, just looked at the perkins manual,

oil pressure = 2.1 - 4.2 kg/cm2 at max speed & normal working temp (30-60 psi)

so maybe 25 psi at idle isnt a huge problem (hopefully)

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just found an oil leak at the back of the oil pressure gauge!

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it was a weep - cant see it being the issue though - had the same pressure drop driving home - fine for the first 7 or 8 miles then gradually drops until the warning light comes on whenever running when stationary

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Oil pressure relief valve sticking when hot?

I sorted my garage into 4 piles of stuff.
1. Stuff I`m keeping
2. Stuff I`m not getting rid of.
3. Stuff I might use..one day.
4. Stuff that might come in handy.
 
have I got one? - will have to have a look at my perkins book

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my new business
 
ah bugger bugger bugger, its on the oil pump - that means dropping the oil sump - which means dismantling the front suspension - not gonna happen any time soon, getting the sump off was the hardest part of the whole engine rebuild!

there is this possibility off a boating forum

"The sudden loss of oil pressure in 4.99 4107 & 4108 perkins is quite common in ag circles. Remove oil fiter assembly ,remove all back ground noise ,ie radios etc, feed a length of 16g wire or similiar down oil outlet hole and listen for click when relief valve snaps back to position be patient as this can be hit or miss.
This problem can be brought on by over revving a cold engine at start up or after a oil dilution issue where extra gunk becomes dislodged jamming relief v/v open."



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http:www.singleusemedical.co.uk
my new business
 
It's worth a try, there might be a little bit of debris on the valve.

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Summer's Coming
 
it happened to me the other week :I

I sorted my garage into 4 piles of stuff.
1. Stuff I`m keeping
2. Stuff I`m not getting rid of.
3. Stuff I might use..one day.
4. Stuff that might come in handy.
 
I flushed the engine tonight and changed to 20W50 oil. Ran the engine for an our at fast idle, the pressure gauge once again dropped to approx 25psi - but the oil warning light no longer extinguishes.

I will try and source a digital pressure gauge at some point to connect up and get a real reading

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http:www.singleusemedical.co.uk
my new business
 
quote:
Originally posted by Navyreg1970

and did it sort itself out?

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no it needed a trip to Martin. My light was permanantly on. Crud from sump held it open. Renewed it and changed oil n filter. Going to flush it out in next few weeks.

I sorted my garage into 4 piles of stuff.
1. Stuff I`m keeping
2. Stuff I`m not getting rid of.
3. Stuff I might use..one day.
4. Stuff that might come in handy.
 
Martin - if you are reading this - any tips for making it easier to get the sump off - or is it just a plain and simple buggerance

The Dog is home....
0049.gif

http:www.singleusemedical.co.uk
my new business
 
I had to disconnect the track rods at the inner ball joints, and then remove the steering yoke as the oil tray fouled against both, even then it was difficult to actually get the pan off as it kept fouling against the oil pump suction strainer - I even had to slacken off the engine mounting bolts to jack the engine up a few mm

- then again i was on my back in a fox hole that I dug out of the ground to be able to get under as I didn't have a lift or stands to put the van up on.

might dig an inspection pit at the new house!

The Dog is home....
0049.gif

http:www.singleusemedical.co.uk
my new business
 
quote:

- then again i was on my back in a fox hole that I dug out of the ground to be able to get under as I didn't have a lift or stands to put the van up on.

might dig an inspection pit at the new house!

The Dog is home....
0049.gif

http:www.singleusemedical.co.uk
my new business





I can highly recommend the hydraulic ramps from DJ Autos[^]

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Summer's Coming
 
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