Oil pressure puzzle - thoughts please
Discussion
Had the car on the rolling road today.
Operator noticed that the car's oil pressure was a constant indicated 30 psi up to about 4500 rpm under load.
But above that, the indicated pressure dropped away gradually to about 15 psi.
Out of gear and revved, it stayed at 30 psi.
Any thoughts as to why?
Oil was full, not fresh but not due for replacement. Good quality Shell 10w60. Engine warmed up, but only about 15 mins into the testing.
Operator noticed that the car's oil pressure was a constant indicated 30 psi up to about 4500 rpm under load.
But above that, the indicated pressure dropped away gradually to about 15 psi.
Out of gear and revved, it stayed at 30 psi.
Any thoughts as to why?
Oil was full, not fresh but not due for replacement. Good quality Shell 10w60. Engine warmed up, but only about 15 mins into the testing.
Thanks both. I will get the sender replaced.
Session was fine thanks Graham. I was basically checking to see that the map was still fine and that the car was not running too rich. Jools confirmed that it was just a tad rich but consistent right across the rev range. AFR around 13.
We then discussed future options and did a power run.
Power had increased about 5% compared to two years ago, when the engine was very new. I guess it has relaxed nicely. It does feel more powerful. So it was 300 bhp and 330 torques at SRR in 2013, now 316 Bhp, 353 torques. Jools normally finds his RR gives slightly lower readings than SRR, so that's not the reason.
Session was fine thanks Graham. I was basically checking to see that the map was still fine and that the car was not running too rich. Jools confirmed that it was just a tad rich but consistent right across the rev range. AFR around 13.
We then discussed future options and did a power run.
Power had increased about 5% compared to two years ago, when the engine was very new. I guess it has relaxed nicely. It does feel more powerful. So it was 300 bhp and 330 torques at SRR in 2013, now 316 Bhp, 353 torques. Jools normally finds his RR gives slightly lower readings than SRR, so that's not the reason.
TV8 said:
Good to know that all is well! It sounds like you are planning to spend on something?
Not for now. No spare loot. Just making sure what the options and costs are, particularly so I don't spend and waste series funds by starting off down the wrong route. My only desire is to be quicker between track day corners.
Will it be quicker if I paint it yellow?
Guys, simple question for those with gauges dropping to zero.
Do you mean zero, or well off the bottom, ie -15?
If zero, then we need to put our heads together.
If below zero, ie the needle has gone to it's bottom stop, then it's the single wire attached to the sender that is loose.
Mine did it first, two miles away from Snetterton at 5.30pm, about to head home after a track day. Luckily for me, I had been at the trackday with a certain Chimaera racer with whom I am well acquainted, and surprisingly (not, if you know him too
) he was still at the track, deep in conversation. He arrived at my A11 layby 10 minutes later and confirmed his own phone diagnosis, and I fixed it myself the next day on the drive.
I am intrigued by the number of people with a similar issue, and by the comment that the real pressure seemed ok. It does worry me, of course it does, but I am a bit reassured now and will follow it up with Mat over the winter.
No, Richard, no money so no plans, but you know how it is, your friends put new shiny bits on their cars and wave their RR graphs under your your nose, and you want to....... But yesterday was just about making sure the car was still correctly mapped and getting Joolz to review the whole picture and make any necessary adjustments. The options discussion was more about seeing why my car is relatively low powered compared to some, and how to correct that cost-effectively. Joolz confirmed that my heads were probably the restructing factor. My only real issue with the car is speed between corners on track days/sprints. The car is perfectly behaved and huge fun on the road, and faster around track day corners than its driver, so for now at least I have time to check my oil pressure on straights! And I have to say I do check my gauges on the straights, and I have never noticed low oil pressure while hacking along at 5500 rpm.
Do you mean zero, or well off the bottom, ie -15?
If zero, then we need to put our heads together.
If below zero, ie the needle has gone to it's bottom stop, then it's the single wire attached to the sender that is loose.
Mine did it first, two miles away from Snetterton at 5.30pm, about to head home after a track day. Luckily for me, I had been at the trackday with a certain Chimaera racer with whom I am well acquainted, and surprisingly (not, if you know him too
) he was still at the track, deep in conversation. He arrived at my A11 layby 10 minutes later and confirmed his own phone diagnosis, and I fixed it myself the next day on the drive. I am intrigued by the number of people with a similar issue, and by the comment that the real pressure seemed ok. It does worry me, of course it does, but I am a bit reassured now and will follow it up with Mat over the winter.
No, Richard, no money so no plans, but you know how it is, your friends put new shiny bits on their cars and wave their RR graphs under your your nose, and you want to....... But yesterday was just about making sure the car was still correctly mapped and getting Joolz to review the whole picture and make any necessary adjustments. The options discussion was more about seeing why my car is relatively low powered compared to some, and how to correct that cost-effectively. Joolz confirmed that my heads were probably the restructing factor. My only real issue with the car is speed between corners on track days/sprints. The car is perfectly behaved and huge fun on the road, and faster around track day corners than its driver, so for now at least I have time to check my oil pressure on straights! And I have to say I do check my gauges on the straights, and I have never noticed low oil pressure while hacking along at 5500 rpm.
I have just spent £10.50 on a set of thermal socks in order to delete my plug extenders, so am a bit cash strapped just now, but my next spend, after the full service in February, will be on a new set of track tyres. I have been using up two old sets this summer, but really need more corner grip (without going to slicks) as even an MX5 was catching me in the corners at Cadwell Park in August. 
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