Oil pressure V8 idle - low?
Discussion
What's your oil pressure at idle on your standard V8?
I've noticed mine gets down to 10-15 psi when at idle, which, according to James Agger (http://www.jamesagger.com/blog/tvr-v8-gauges/), seems to be right. But I don't remember it used to go so low. It's quite alarming. It used to be above 20 psi all the time.
At speed it will be 35-50 psi.
The car's going to Colin at TVRSW next week, but I wondered if anyone had any comments?
I've noticed mine gets down to 10-15 psi when at idle, which, according to James Agger (http://www.jamesagger.com/blog/tvr-v8-gauges/), seems to be right. But I don't remember it used to go so low. It's quite alarming. It used to be above 20 psi all the time.
At speed it will be 35-50 psi.
The car's going to Colin at TVRSW next week, but I wondered if anyone had any comments?
That's a little on the low side at idle but not disasterously low, especially given that the senders aren't always reliable. I do suggest you confirm that the low oil pressure warning switch and lamp works. These also vary but would usually be set to around 7 psi plus or minus a couple. It wouldn't be unusual for the warning lamp to flicker intermittently at idle on a hot worn engine and as long as it picks up to 20+psi when you bring the revs up it should be OK. Obviously the oil grade makes a big difference to the expected pressure, but it will also vary according to the condition of the engine.
GreenV8S said:
That's a little on the low side at idle but not disasterously low, especially given that the senders aren't always reliable. I do suggest you confirm that the low oil pressure warning switch and lamp works. These also vary but would usually be set to around 7 psi plus or minus a couple. It wouldn't be unusual for the warning lamp to flicker intermittently at idle on a hot worn engine and as long as it picks up to 20+psi when you bring the revs up it should be OK. Obviously the oil grade makes a big difference to the expected pressure, but it will also vary according to the condition of the engine.
How might one do that? 
What you describe is what my Chimaera does and has done for the last 25,000 miles. As said above, the senders measure something, but not true oil pressure. I take the view that as long as it reads as usual you are ok. When it scares me is when it reads zero with the water temp at 90-95 and the speedo at 120 on a track day. Having said which I have a baffled extended sump filled with 9.5 litres of 10w60 racing oil, and it never loses any, so my conclusion is that the sender is in a cul de sac.
The only twice it had a minus pressure was when the lead came loose on the sender, as the needle stop is well below zero.
The only twice it had a minus pressure was when the lead came loose on the sender, as the needle stop is well below zero.
V8S said:
How might one do that?
With the handbrake on, switch the ignition on without starting the engine. You should get 'handbrake', 'no charge' and 'no oil pressure' warning lights. It may not be obvious which is which. You can identify the handbrake warning by releasing the handbrake for a moment. Start the engine - the 'no charge' and 'no oil pressure' warning lights should go out. Rev the engine and switch off. The low oil pressure light should stay off. The no charge warning should come on while the engine spins down and go out as it stops.The no oil pressure warning light isn't always connected, and could have failed. You need to know which lamp it is and confirm it works before you rely on it to tell you when you don't have oil pressure.
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