V8 No Oil Pressure

L

leymar

New Member
Just been to start my V8 after 6 weeks. No oil pressure at all, with oil pressure light on. It was running really well when I put it away. I was wondering whether it was the oil pressure relief valve, but I am not sure what this does, nor whther taking this off requires the oil pump to come off as well.

Any advice gratefully sought

Thanks a lot

Mark
 
That sounds like a real EEEK! moment. The Rover V8 is known to drain down the oil if left stood for an extended period, or to fail to prime the oil pump when the oil is changed. It is unusual for it to happen after only 6 weeks though.

It should fix itself if you take the plugs out and motor the engine on the starter motor for a while. If it doesn't then take the oil pump out and pack it with vaseline and reinstate. In both cases the objective is to prime the oil pump. It would be very unexpected indeed if the problem was with the relief valve.

Once this is OK then a bit of consideration as to why this happened is due. How many miles does the engine have on it? What oil pressures do you have with a hot engine running and at idle? What do things look like in the rocker covers - black and cruddy or clean and brown? What oil are you using and how often is it changed? (should be an old fashioned 20/50 with lots of ZDDP addittive and be changed at 3,000ml intervals - they hate modern oils)

Hope that helps

Chris
 
Thanks Chris

The engine was rebuilt only about 5k miles ago, & I change the oil every year with 20/50, it will at most do 1k miles a year. Oil pressure has been no problem at all.

I could imagine the oil draining away if it was parked on a slope, & I have had this happen when jacked up too high at the front, but it has been level parked. The only difference is that it went to a garage for a service in May, they said that they had replaced the oil filter with an SD1 one, as they couldn't get a P6 one to fit. I have always used Fram or Crossland filters with no problems. Anyway the SD1 one that is on it, is as wide as a P6 V8 one, but is longer. I wonder if this is anything to do with it - pump needs to work that bit harder to build up pressure after a lay up?

The joys of P6 ownership!

Regards
Mark
 
Aha! There is the problem! All V8's (including the SD1) need a particular and unusual type of filter. They have a rubber flap inside the top rim which is supposed to stop oil draining back. If the garage got in a muddle with filters then the chances are they've fitted one without.

The P6 front cover and SD1 front covers are different - the SD1 has a different thread for the oil filter and also a longer oil pump housing (for the high flow oil pump). It isn't possible to use an SD1 filter on a P6 front cover because of the thread difference, but it's possible your engine could have an SD1 front cover. That would be good because of the better oil pump.

Oil filters for the P6 would be Fram PH25, Unipart GFE 145, Rover RTC 3186, Coopers Z15A, Wix 51069, PL 14006 etc. The Fram PH10A might also fit - it's longer than the 25 and might be a tight fit against the bodywork, but has the same non drainback device. I can't help if you have an SD1 front cover as I don't have a listing for them.

Chris
 
Just to be clear, the engine front cover and the oil pump front cover are entirely separate, and can be mixed without problems. I have an SD1 front cover on my engine, but I use a P6 oil pump front cover. You can also do the opposite without issue.

The spigot which accepts the oil filter on the P6 oil pump front cover is larger in diameter than SD1 and all later oil pump front covers, so swapping filters unless the oil pump front covers have been changed is an impossibilty.

I wrote a lengthy piece on this topic....viewtopic.php?f=5&t=6290

Hello Mark,

If your oil pump has lost its prime, then you really have little choice but to remove the filter and oil pump front cover, pack around the gears with petroleum jelly, refit cover, fit a new filter of the correct type half filling with oil before doing so, and go from there.

Can I ask please,..why are you only able to drive your P6 no more than 1000 miles per year?

Ron.
 
Thanks very much folks. I'll replace the filter and prime the pump as you saY & let you know. Don't you despair of garages these days?

Hello Ron - Work gets in the way unfortunately. You never know 1 year I may win the lottery
:LOL:

Regards

Mark
 
If you don't want to strip and prime the pump itself, either buy or make a priming tool, remove the distributor and use an electric drill to prime the pump up until you get pressure. ISTR Rimmers sell them.
 
I prefer the dizzy out option, then you don't even start it till you have oil round :wink:
 
Hi Mark,

Have a look at the 5th post on >this page< for the oil pump priming tool that I made up.

I found it a lot better with the dizzy-out option - you'll see oil seeping out round the rockers and, if you have the ignition on, a helper will see the oil pressure gauge coming up.

Good Luck! :)
 
I read this cheat for priming the pump on another forum and the result came back good.
hi mate, the pumps not primed,remove rocker cover,No1 pot No1 valve closed,take out the rock shaft retaning bolt then get a oil can(pump type) pump loads in as much as pos, replace bolt and cover,give it a go!!!
Never heard this suggestion before but sounds an easy option :|
 
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