Rising oil pressure

[adrianr]

Hi all

After years if nothing to really report the oil pressure has been apeearing to be rising the last few weeks. Needle Used to sit on the 2/3 mark when cold and about halfway when at operating temp. Now sits between 2/3 and the very top when cold and just below the 2/3 when at operating temp. Interestingly on tickover it's just a bit higher than it used to prior to this change in reading. I know the guages are not accurate but its this new behaviour that stands out as odd.

Did an oil change two days back as part of a service from 15/40 to 10/40 semi. No real change but now the oil pressure needle sits a bit lower on the gauge when at normal operating temp.

Any thoughts please? Oil pressure relief valve sprang to mind? If so Where would that be in the engine and are they prone to going faulty after just 19 years in service! Ha

Thank you

 

[adrianr]

Oh and is the oil pressure relief valve serviceable? Ta

 

[Rich Sims]

it could be that bearing(big and main) are worn and are turning round and partially blocking off oil ways, something thats needs to be looked into soon.

 

[adrianr]

thank you. its possible.

Big end bearings were redone with ACL bearings 70,000 miles back,

oil changes every 3000 miles and never seen any debris on the magnet

still feel its the oil pressure relief valve.

 

[Rich Sims]

The oil relief valve on my 3.0td is just a plunger and spring under a 24mm bolt head on the side of the engine so I can't imagine it's much different to yours, they can get stuck.

 

[Chris]

I have a full oil pressure testing kit - if you're over this way ever, we can plumb it in and read what it says. We don't know how that gauge is calibrated really. top to bottom might be less than 1 psi total! Or...1000. Mine reads zero, but when I plumbed it in it was bang on the money. Kit cost me about £45 IIRC.

Chris

 

[adrianr]

Thanks Rich. Ill have a look see.

Thanks Chris - I spoke to Julian V earlier and had a catch up with him. He also suggested i test it in any case.

 

[adrianr]

I had a look at the manuals on my iPad last night.

The oil pressure relief valve is on the left side of the oil pump which is under and left from the fan as you face the engine bay from the front.

ill pop it out later and have a look.

 

[adrianr]

torque 34 lb ft on the bolt
Correction 31 lb ft

 

[Roger Fairclough]

it could be that bearing(big and main) are worn and are turning round and partially blocking off oil ways, something thats needs to be looked into soon.

This is unlikely as each shell has a tag which locates in the cap or the main body of the block/con-rod. The tag locates and prevents the shell from moving. Any increase in the shell/journal allowable tolerance results in a reduction in oil pressure plus the classic knock (especially on the over-run) for a big-end, or a rumble on the mains.

Roger

 

[joinerman]

Your dead right Roger, pic shows the tabs top right & bottom left.

 

[adrianr]

Well i had a look see at the oil pressure relief valve - alternator off, then the large 24mm (I think (!) bolt, catch the little bit of oil that dribbles out when you remove the nut and the spring behind it.

fished out the metal bit that floats. all looks fine, it certainly was not stuck.

popped it all back together fired her up and the oil pressure still at the higher level.

hmmm..

its not risen any in the last week so ill keep an eye on it.

 

[Chris]

It's all this warm weather mate. Thinning your oil. That'll be it for sure. Oh yes. It's Summer you know.

C

 

[Jon Wildsmith]

Just as or more likely to be a change in either the sender or the gauge than an actual change in pressures Adrian, you really need to see what a proper gauge says and ignore the Toyota one.

 

[Roger Fairclough]

I agree with Jon on this. The standard Toyota gauge is electrical and any increase or decrease in resistance due to corrosion or dirt could easily change the readings.

Roger

 

[adrianr]

Thanks fellas. The gauge it about as accurate as the met office weather reports I think!!

i did clean the engine a few days before the change happened - degreaser worked in with a paint brush then rinse with the house. pulled all connectors and put contact cleaner in everything. then doused the engine in wd40.

ill get a reading from a reliable gauge at my mates garage when im passing.
its quite novel having a gauge that does move about a lot!! LOL

 

[Roger Fairclough]

Why WD40?

Remember, it's inflammable.

Roger

 

[adrianr]

Understood - Julian V recommended it.

 

[grantw]

Quick google and this came up ...

http://forums.bimmerforums.com/forum/showthread.php?t=1756116

Almost unbelievable results ...

But think from Julian V it must be for corrosion resistance & water dispersant properties?

 

[adrianr]

Grant - JV - exactly