Oil pressure V12

[royal1]

Hi all,

I am looking to buy a Daimler Double Six. One I have looked at is a 1993 model with 50,000 miles on the clock. Near perfect, but when hot the oil pressure is reading 40 psi. Is this a bit low?

Thanks.

Martin.

[greenlane]

Hi,
40 psi seems a little low to me, but this might still be ok. The senders are notoriously unreliable so without replacing this you can not be sure.
The psi on my own 76, V12 with 80,000m on it was all over the place when I bought it, so maybe why it was sold?
The car ran so well and was a good price, so I took a chance . When I fitted a new sender unit it always stayed just over 60 psi and was entirely reliable for the next 10,000 miles , and that's a car from the dark days of British Leyland!
I seem to remember reading that the pressure on a perfect engine is around 70 psi . So I think I would ask myself how well has the car been serviced, how accurate is the mileage, is the oil the right grade and been recently changed or could you come to some arrangement to fit a new sender, I don't think they're too expensive .
I don,t know what is an acceptable drop for age and mileage but they're supposed to be pretty tough.
Hope this helps, Simon.

[royal1]

Hi Simon,

Thanks for the reply and comments. I have seen a few posts where 60 to70 psi is quoted.
The chap who carried out the inspection is a qualified engineer and runs his own company, Classic Assesments.
He gave me a comprehensive written report, and prior to that when he phoned me after the inspection, he said he wanted to drive the car home, it was that nice. It is an import from Japan, so history/servicing might not be accurate/genuine. As I say, the car is near perfect so would suggest the mileage is genuine.
However, it will be a difficult decision as I don't want to chance having to fix the engine. I will discuss the oil pressure with him.
As I type, I am expecting a call from him as he is looking at another one identical to this, also imported from Japan, except it is an '89 with only 23,000 which in the advert, is warranted. At that low mileage that could also be a problem, standing etc.
I will let you know the result, which one (if at all) I decide on.

Thanks again,

Martin.

[robv12]

a V12 is a low pressure engine at best, hot they will often drop to as near as damn if zero on the gauge, the trick is to pick the revs up to 1400 rpm, the pressure should come up to 40/50 hot. the V12 has huge main and big end bearings and rarely suffers oil pressure related problems, i have seen cars with almost no oil in them knocking away merrily, fill them up and away they go, as a testament to this ask any one who was with me at Newby Hall two years ago, a 1993 6.0 XJS driven from Newcastle to Newby, I was called to help the owner, we found it with NO oil showing on the dipstick at all, the owner trailered it home, filled it with 10 litres and away she went like new and is still going strong to this day

V12 will do intergallatic mileages, the key to long life on them is cooling, it was marginal at best when new and got worse as we got into the last 6.0 cars where problems occur with lack of space for adequate radiators, these cars need to have a cooling systen 100% efficient

[royal1]

Hi Rob,

I am guessing your name is Rob from your username.

I have just replied to your post, but it's disappeared, so here it is again. I'm not fond of computers!
It is a great relief to read your comments as it was the oil pressure which was my main concern.
The engineer who checked the car was aware of the importance of the cooling and was particular about the many parts of it.
I will change the oil and filter although they were carried out quite recently.
The brake fluid is clean and clear. The box is perfect and kickdown is instant.
I have read a lot on the wiki site about both the engine and GM400 so it is doubly reassuring to read your comments.
He was impressed enough to want to drive it home, so hopefully I have made the right decision. I have not driven a V12 before so hope it won't disappoint.

Thanks again all for the replies, and have a safe and pleasant Xmas.

Martin.