oil pressure

[Tim and Dot]

I have a 1996 Roadsport with a k series supersport engine. I have changed the oil using Mobil 3000, 15w 30 fully synthetic, filter and foam sump insert. When the car is running hot the oil pressure drops to very near the red mark on the gauge on tick over then moves to around 2 bar when running at normal road driving is this ok ? Im driving to Italy this summer and it worries me!

[Stationary M25 Traveller]

15w-30 doesn't sound right for a k-series.

 

I have always used 5w-50 ....... thinner on start up and thicker when hot

 

I ditched the foam long ago.

 

Also changed electrical sender/gauge for mechanical gauge .... reliable readings you can trust.

 

Done a big hot trip to SW France and Andorra in 36C shade temperatures .... no issues.

[Roadsport06]

You oil is a little thin, a 0w40 would be better, or the 5w50 Motorsport oil if you are going in hot conditions. Tick over 20 psi when hot and full beans about 55psi. Read about the senders, they are rubbish so go for a mechanical gauge for peace of mind.

[Tim and Dot]

Just checked my oil is 5 w 30. do you think I should change it for 5w50 then?

[tweeky]

Go for the mechanical gauge too, as it has been said the caterham set up isnt great

[Stationary M25 Traveller]

5w-50 is better for a hot engine

[myothercarsa2cv]

It's probably fine and the sender is faulty, but don't risk it. Use the right oil, ditch the foam, and fit the mechanical oil sender. Do the gasket mod at the same time too.

[willmac]

I've got a brand new mechanical gauge set up supplied by "THINK", still in the box and complete with a smaller LED warning light I purchased separately ( also have the big red light warning light ) that I will be selling if you are interested ? BM me if you need further details.

[Bob L]

Ditto on 5w-50 fully synthetic and also gone mechanical after everyone else’s comments 😶‍🌫️ Near full screen deflection and less damping gives much better peace of mind, an inexpensive and simple mod for a damp w/e morning. Probably one of the best upgrades I made.

[the.vet]

I've got an 1800 k that is similar but running 5w50. Shows very low on the gauge at hot idle, cold start it's up at 4. Full beans it sits at 2 or so. Assumed this was normal as I've hired a couple that have been the same !?!

 

 

Graeme

 

 

[Andy Lef]

I've got an 1800 k that is similar but running 5w50. Shows very low on the gauge at hot idle, cold start it's up at 4. Full beans it sits at 2 or so. Assumed this was normal as I've hired a couple that have been the same !?!

 

Same setup here but mine reads 6+ on warm up and then settles to 4 and just under.

[Stationary M25 Traveller]

Hot idle should be above 1 bar (15psi) .... 1.5 bar (22psi) is good.

 

Cold start expect up to 5 bar (75 psi)

 

Hot engine and high revs 4 bar (60 psi)

 

Don't trust an OE electrical gauge

 

Changing to a mechanical gauge costs around the same as one new electrical sender !

[Fil M]

My oil guage (Caterham sender unit) was reading low so on service I got another one to see how long it will last (go mechanical next time maybe) ..it sounds like your sender unit is showing classic signs of giving up. The water temp senders are even worse!!!!

[Roger Ford]

Why on earth did you put 15w 30 in it? That must have cost a lot of money, yet it's totally wrong for the engine - too thick when cold and too thin when hot.

 

Don't necessarily believe the "ditch the foam" brigade. Most of the race engine builders don't subscribe to that theory. I know Dave Andrews is vehemently against it, but other aren't.

[johnv]

my electrical sender (in the stack dash) now reads 29psi hot, high revs, my mechanical one reads 65psi!

[finmac]

Wilmac - YHM cheers

[Anton]

LE0 is an 1800K and I've had to change the sender at least once a year! Redline will be changing the gauge for a mechanical one very shortly.

 

I have always used Comma Syner Z 5W-30 oil (this is for a heavily used 03 car with 102,320 miles on it)

 

But when it was working, the gauge showed 5-6 bar cold, 3.5 hot at 40mph and just above the red when idling hot. At 70 mph hot it registered about 4-4.5 bar. It will be interesting to see what the mechanical gauge says.

[Tim and Dot]

Thanks for all your comments, I have now changed my oil for 5w 50 however the low tick over pressure when hot still persists. Just hovers on the edge of the red on the gauge. I have also noticed the needle is jumping about. So where do I get a mechanical gauge? do I need a different sender unit too?

[Stationary M25 Traveller]

No sender ... just an adaptor to connect a small capillary tube in place of the sender.

 

Terry Higginson supplies the gauge kit and adaptor ... but he was struggling to get new stock recently. Will ask him.

[Roadsport06]

Good evening, Willmac has written he has a MOPG for sale.

Think automotive will supply all. Call them, tell them what you want here.

Plenty on here so do a search. Easy to fit.

[the_village_idiot]

I know caterham reccommend 10/15-50 but I wonder is this really necessary?

 

You can get better cold start protection with a 5-40. If you have an oil cooler the oil will never get too thin. On cold evenings my oil cooler and radiator are too good- I have to occlude part of each radiator with duct tape to get the water and oil at optimum temp.

[Back2a7in0xfordshire]

My SLR starts up at just above 4, then when its hot sits between 2 and 4. And blasting depends on temperature but around 4, higher when a bit cold, lower when hot.

 

I was a little concerned that it sat at 2 when hot - but clearly this is common

 

[Roger Ford]

Quoting the_village_idiot: 

I know caterham reccommend 10/15-50

They recommend 5w 50, don't they? Same cold start performance as 5w 40, but thicker at high temperature. The "it'll never get to high temperature so there's no point in using it" argument is interesting, but not one I'd really go for.

 

[mav]

Yes Roger, 5w/50 not a 10 or 15w/50

[Birkin S3 ZA.]

A bit of information a bit of topic but interesting I hope.

 

I have noticed over the past 6/8 years or so the off road bikes have been recommending thinner oils,from 15/50 to 5/40 and now 5/30 in winter 0/20.

 

Most of it is for better cooling in the oil system as it flows faster and removes the heat from the hotter areas.

 

All the new four strokes run up to 11000 to 12000rpm and never seem to have lubrication problems, the oil will run hot but never a problem now.

 

About 10 years ago I have seen oil run hot enough to melt the solder on ignition coils that run in oil, it even happened to me twice whilst racing when we used 15/50 oil.

 

My Zetec is filled with Castrol 5W/40 Synthetic oil and works very well, one day I will try some of the 10W/50 Castrol bike racing oil.