Low oil pressure on hot days - 1.6 K-Series 2002

[wpqs]

I have a 1.6 litre  K-Series dating from 2002 and notice low oil pressure at 3,000 RPM or less on hot days after the engine has been running for 30 minutes or more on a gentle ride through the countryside. The gauge needle sometimes goes slightly into the red zone or just above, but the pressure does rise slightly when engine speed increases beyond cruising levels. There is plenty of oil in the engine. Immediately after startup the gauge is in mid-range. Might an oil cooler improve the situation, or is this something that I don't need to worry about? Any advice about oil cooler kits would be welcome.

[Jonathan Kay]

What oil is in there and how old is it?

When hot and idling does the pressure go up immediately on a small blip?

Jonathan

PS: Standard question... are you aware of the problem with the foam in the sump and happy with your decision on it?

[Paul Richards]

Assuming you have the standard electric gauge. The senders are very poor and unreliable and are the main reason for poor readings on the gauge. I'd start by changing the sender or better still and for the same price swap to a mechanical gauge. 
Have you still got the foam baffle. Again a source of some problems although less likely if you are reading good pressure when cold. 
What reading do you get when cold? 

[SM25T]

Change to a mechanical gauge, change oil for 5W-50 with a new filter. If still fitted, remove the foam sheet from the sump and drill two drain holes in the sump gasket shelf to help oil return to the sump. Photo is available on line.

[wpqs]

The oil is 8 months old and yes the needle does jump when I blip the accelerator. When cold the pressure is midway - ie. 4 in scale of 0-4-8

I would be happy to swap to a mechanical gauge. Do you have any suggestions / websites?

Many thanks for suggestions!

 

[Wrightpayne]

Think Automotive - they sell a kit for the seven. Demon Tweeks list one too.

[Jonathan Kay]

"I would be happy to swap to a mechanical gauge. Do you have any suggestions / websites?"

Parts list and supplier. And lots of discussion in the archives.

But i don't think that what you're describing sounds like a problem with either the sender or the gauge.

What's the oil in there?

Jonathan

[East Kent AR]

I had the same problem with my K series. It was the sender and I'm on my third after 11 years of ownership. They don't last long. I'm not a fan of mechanical oil pressure gauges. Contact Redline and they have them in stock. A five minute job to replace.

Piers

[timb2117]

I drove my "new to me" car home about 600kms in one day dreading that I'd bought a lemon with atrocious oil pressure :( Got home first job, new sender and gauge and - perfect healthy engine!  And it only took 6 weeks for my gnawed down nails to regrow.

In other words don't trust it get fresh sender your cuticles will thank you :)

[Geoff Brown]

A member in my area had a similar problem & he went down this path.

Just to reassure checked engine oil pressure with this: Machine Mart/Clarke test kit CHT712

Then totally reassured he changed the pressure sender & hey presto. Later this was changed for a direct reading system.

[john milner]

When my sender packed up it stopped reading anything or went to max so I'm not so sure a fluctuating pressure with hot oil reading is the fault of the sender. Sump foam breaking up might do something weird.

Test for failed pressure sender. https://www.tom-seven.stillgame.ch/Main/Oil%20Pressure_logic.htm

I doubt that a cooler will help unless you are a racer or drive somewhere very hot.

Stack mechanical gauges are probably the most popular choice for Caterham's.

[John Vine]

The Mocal OPG100 is also a popular choice.  That's the one I have (but with a white face).

JV

[John Vine]

This is the kit I got from Think Auto for my Duratec:

The gauge is a Caerbont unit:

JV

[wpqs]

Thanks for the advice everyone. I will start by replacing the sender, but also take a look at the sump baffle. I use Castrol Edge10W-60 oil by the way.

[John Vine]

If you plan to stay with the standard electronic sender, it would be worth considering mounting it remotely.  The standard sender is very susceptible to engine vibration, and that's what tends to kill it prematurely.  A remote mount pretty well solves this problem.  CC used to sell the remote kit but I think you'll now have to assemble it yourself.

JV

[22daz]

I persisted with the standard electrical sender for years. Got fed up when one only lasted a couple of months so I went mechanical from Think Automotive and it was one of the best things I did to that car. I had total confidence in the readings thereafter. Super easy job too. 
 

22daz

[SLR No.77]

I have the Stack mechanical gauge, far more visible in all light conditions and I prefer the 270 degree sweep that the mechanical gauges have. I bought all the plumbing bits from Think. The gauge is so much better than standard that I've also fitted a matching coolant gauge.

[East Kent AR]

I see you are using Castrol 10W-60 oil for your K series. The recommended oil for the Rover K is 5W-50 (Comma). What are the benefits/disadvantages of using the Castrol oil.

I still believe that your issue is the sender.

Piers