R500 Losing oil pressure whilst on track!

R500 Losing oil pressure whilst on track!

Author
Discussion

Ducati07

Original Poster:

202 posts

221 months

Monday 3rd August 2015
quotequote all
Chaps,

Anyone got any idea of the cause of this - i was at Castle combe today and lost oil pressure - the warning light came on, pulled into the pits and then even after idling for a bit it was still on a red light with the stack dash warning, but gradually regained pressure again. Thankfully it was near the end of the day so packed up and trailered it home - took it out for a blast when i got home and the pressure was fine at around 65-70. Help!!! Im aware of the seriousness of getting this wrong!!

Thanks in advance!

DCL

1,215 posts

178 months

Monday 3rd August 2015
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What engine? Duratec or K series?

Ducati07

Original Poster:

202 posts

221 months

Monday 3rd August 2015
quotequote all
Sorry good point, k series.

oil level is fine btw.

DCL

1,215 posts

178 months

Monday 3rd August 2015
quotequote all
If it has recovered to normal levels then possibly no harm done. But it suggests that the bearings got very hot. Things quickly add up to reduce oil pressure - clearances increase, oil thins, and pump become less efficient. Maybe review the viscosity of the oil you use, and consider an ester based racing oil if you are going to do a lot of track work.

pikeyboy

2,349 posts

213 months

Monday 3rd August 2015
quotequote all
Are you sure the pressure switch is working properly I've had them weep oil before not with a stack though. Might be worth checking with an analogue gauge.

Ducati07

Original Poster:

202 posts

221 months

Monday 3rd August 2015
quotequote all
Someone mentioned it may just be the sender, any thoughts? It looks like theyre cheap as chips to replace. Feels a bit trial and error!!

BertBert

18,954 posts

210 months

Monday 3rd August 2015
quotequote all
How hot was the oil?

Ducati07

Original Poster:

202 posts

221 months

Monday 3rd August 2015
quotequote all
Dont know, by the time i got back to the pits and it was idling it was running at normal temp which is high 70's.

Is it slightly bizarre that once i got home it was fine?

pikeyboy

2,349 posts

213 months

Monday 3rd August 2015
quotequote all
Ducati07 said:
Someone mentioned it may just be the sender, any thoughts? It looks like theyre cheap as chips to replace. Feels a bit trial and error!!
Before I took the sump off to to check mains big ends or condemned the engine I'd be looking at things in this order that only cost a few quid.

Sender
Change oil
Check actual prs with analogue gauge cheap as chips from merlin motorsport
Check bottom end brgs
Retire to pub to drown sorrows


Edited by boy on Monday 3rd August 23:20

Ducati07

Original Poster:

202 posts

221 months

Tuesday 4th August 2015
quotequote all
Thank you that's v useful.

What's the general consensus - do people generally use an ester based oil if it's being tracked regularly?

Ducati07

Original Poster:

202 posts

221 months

Tuesday 4th August 2015
quotequote all
Ps whilst I've only had the car for a few months, the engine was refreshed only 1100 miles ago!

pikeyboy

2,349 posts

213 months

Tuesday 4th August 2015
quotequote all
Ducati07 said:
Thank you that's v useful.

What's the general consensus - do people generally use an ester based oil if it's being tracked regularly?
Well I would yes. Fusch pro s is good one, but there are others. just make sure it's ester based, there are synthetics and synthetics, ask opie oils for advice it's free.

james7

594 posts

254 months

Tuesday 4th August 2015
quotequote all
Just a thought but....
Are you certain that the oil is at the correct level ie are you checking it the right way?

As the engine is fairly fresh and it is ok on the road and the pressure comes back at lower revs it sounded a bit like it could be due to the oil level not being correct

fergus

6,430 posts

274 months

Tuesday 4th August 2015
quotequote all
On the Caterham dry sump, there is also a small gauze filter on the end of the scavenge pump supply. It's worth checking this isn't obstructed with anything.

You may also want to check the clearances on the oil pump rotor.

Give Dave Andrews a call to discuss your issues. It's way cheaper to address any issues now, than wait until something fails. You may get away with a set of big end shells, etc at the moment, rather than a crank regrind, or even a holed block if things go very wrong.

Ducati07

Original Poster:

202 posts

221 months

Tuesday 4th August 2015
quotequote all
Anyone know DPR Motorsport in Surrey? They race Caterhams, was going to get them to take a look at it as they're local.

Feel like the consequences of getting it wrong are so major that I don't really want to take any chances by trying to diagnose it myself.

re checking oil level, I'm treating it like I would a standard dry sump - let the engine run up to operating temperature, let it cool for 5 mins then check the level - is this correct? Very slightly overfilled it for Castle Combe in anticipation of losing a fraction and it being a newly refreshed engine.

james7

594 posts

254 months

Tuesday 4th August 2015
quotequote all
Ducati07 said:
re checking oil level, I'm treating it like I would a standard dry sump - let the engine run up to operating temperature, let it cool for 5 mins then check the level - is this correct? Very slightly overfilled it for Castle Combe in anticipation of losing a fraction and it being a newly refreshed engine.
Do you mean like a standard wet sump?

Most dry sumps are usually checked with the engine running. There are a few r500 owners/ex owners on here, I am sure they will confirm the correct method.

Ducati07

Original Poster:

202 posts

221 months

Tuesday 4th August 2015
quotequote all
I always thought that checking a dry sump with the engine running was wrong! I'll ask the Q - separate post coming up...

SimonRogers

146 posts

157 months

Tuesday 4th August 2015
quotequote all
Run the engine up to temp/pressure and then shut off. Check the level via the tower asap/immediately.

Otherwise the oil runs back down into the sump.

I would have thought if its the correct level after 5 min then it has to much oil in there but it would be throwing out at the catch tank in that case?

Ducati07

Original Poster:

202 posts

221 months

Tuesday 4th August 2015
quotequote all
there was a couple of mm in the catch tank, I'm assuming it's probably about the right level now.

Planning on changing the sender as a start, I haven't got underneath the car yet to take a look at where they are but from images it looks like they literally just screw on behind the oil filter? Do i have to drain the oil first / anything else I need to know?!

Thanks!

fergus

6,430 posts

274 months

Tuesday 4th August 2015
quotequote all
Ducati07 said:
there was a couple of mm in the catch tank, I'm assuming it's probably about the right level now.

Planning on changing the sender as a start, I haven't got underneath the car yet to take a look at where they are but from images it looks like they literally just screw on behind the oil filter? Do i have to drain the oil first / anything else I need to know?!

Thanks!
I'm not sure your symptoms are sensor related. If the OP reads normal levels when driving normally (circa 4 bar, ~60psi), but falls when the car is thrashed, whilst a thicker oil may mask the symptom, I think you may have clearance related issues somewhere.

Is the sensor a solid state version, or a VDO mechanical type? In either case, I'd consider remote mounting the sensor via a 12" length of aeroquip style braided hose, to alleviate the chances of a vibration related failure (although less likely to affect a solid state sender).

A call to a respected engine builder would be a prudent thing to do, even for a quick discussion.

PS as already mentioned, you want the tank full from the scavenge pump to be able to assess the level. If you wait too long with the engine off, the sump will be full again, and the tank showing a lower level.

Depending on what dry sump system you have, "over filling" a bit will only result in the catch tank getting the excess. If you go down this route, make sure the connections on the hose from the oil tank exit to the catch tank are sound....

Edited by fergus on Tuesday 4th August 13:58