loss of oil pressure

[arthur67]

Hi
I changed the oil two weeks ago used a good 20/50 oil and new oil filter fram PH2870A. Sometimes when it starts up I have no reading on the gauge and the engine starts to knock I presume no oil pressure? I have started to crank it over with the throttle wide open so it won't start to build up some pressure.
The car had a lotus filter on and it never done this.Have I got the correct filter fitted?
Any advice appreciated Thanks Arthur

[gjz30075]

I think 20/50 is too thick, for a street car. When first started, it takes a long time for thick oil to reach all extremities. I run 10/30 or 10/40 and I'm thinking of trying a 5/40. The quicker you can get the oil to reach all places it needs to go, the better.

Greg Z

[CBUEB1771]

Arthur,
The FRAM PH2870A is suitable for the Twin Cam, this basically all I have ever used in my +2 since the late 1970s. However that does not mean you have not gotten a duff filter. Many years ago I had the same problem on the one occasion that I used a Mann filter instead of the FRAM. Changing filters solved the problem. I would try another 2870A.

[ericbushby]

Hello Arthur,
I did an oil and fiter change using Miller Classic Sport 20/50 and a filter from the local car shop of the same number as the old filter.
After about 60 miles the oil pressure started to drop before collapsing to zero just as I pulled up at a friends house. I recovered the car the next day.
I did everything I know to find the problem but could find no faults or blockages.
A new filter was ordered from Sue Miller without specifying the type and was fitted.
There have been no further problems.
I still do not know what happened and I do not know enough about filters to speculate, but in future I will be buying filters from a known reputable source.
It just might be worth trying this in your case. Best of luck.
Eric in Burnley,
1967 S3SE DHC( running well)

[Lyn7]

Hello Arthur, I have experience of a faulty Fram filter from a number of years ago. After an oil and filter change I completely failed to get oil pressure on start up. It was not on an Elan so I could not pre fill the filter. When the bearings started to knock I switched off . The only thing that could be suspect was the filter so I replaced it and never had the problem again . I would replace your filter before you drive the car any more. Oil and filters are cheap compared to an engine rebuild. Good luck.
Lyn...

[tvacc]

Oil not the issue. All I run in my twin cams is 20/50. I vote for the filter.

[Quart Meg Miles]

I've used a Halford's HOF 203 (screw on type) for many years with 20/50 and no problems.

[arthur67]

Hi thanks for the replies I have bought a Halfords oil filter (thanks meg) not fitted it yet as it has not done it since.
3 or 4 times it happened but it seems to be OK now.
Thanks again Arthur

[Lyn7]

Hi Arthur, you might not have a problem at the moment and it might have only happened 3 or 4 times?
If it happens when you are not looking and otherwise pre occupied it could turn into a disaster.
For the price of an oil filter I would change it sooner rather than later. If it is the filter (favourite option) there might be something loose in there to prevent oil flow intermittantly.
After changing the filter I would still keep a close eye just in case.
Lyn...

[oldchieft]

Please change the filter.

My guess runs like this. The filter collapsed and stopped the flow, then burst and you are now flowing unfiltered oil and bits of broken filter.

Take the filter off and section it with a hacksaw, if you find a scrunched up mess you might have to think about complete strip down of the engine.

Jon the Chief

[AHM]

Greg,

Over here oil was 20/50, everything ran on it, the choice was Duckhams or Castrol. It was the default, manufacturers even specked it for old models that previously had 30 or 40 monnograde. There are seemingly endless options in oil now, so there is a good market in "Classic" oil which is mostly 20/50 and some monogrades for real men!

Personally I use 15/40 as I think oil technology has moved on a bit. But I wouldn't go below 15W. The oil will get their quickly anyway, the clearances are wider and it needs to have some film thickness for the first few minutes after it has got there. Thinner oil with wider clearances might not be so good, and will likely be noisier when cold.

[Chris]

Hi Arthur.
Could I point out that the Lotus twin cam engine requires a simple full flow oil filter, such as TJ Filters FB 5312 or FB 2099. The FRAM PH 2870A which you are using contains an anti drain valve, a pressure relief valve, and can also contain a stand pipe and an anti syphon valve, non of which are desirable for the twin cam because of its location. Fitted below the engine the oil cannot drain into the sump, therefore an anti drain valve is not required. The stand pipe, and anti syphon valve are only required in an inverted installation and the pressure relief valve is in the oil pump.
Therefore, I would suggest you forget about filter makes, and just fit a TJ Filters FB 5312 or equivalent full flow
filter of 79mm diameter-114mm tall, with a 3/4"x16 UNF thread.
I have been using FB5312 filters since 1991, (fitted without pre filling as this can cause an air lock.)
The FB 2099 filter is also suitable but is only 78mm high.
I hope you get over your problem.
Cheers
Chris