Lotus Elan

Oil Pressure Constant

PostPost by: Paul Steer » Tue Jul 20, 2004 11:02 pm


73 +2S130/5 The oil pressure guage on the car sits at 35psi virtually all the time ,only dipping slightly at idle to say 30 even when hot. This does not ring true to me. The car has had an oil cooler fitted.
Also the fuel tank reads just less than 3/4 when brim full, could they both be influenced by a dicky voltage regulator a problem I have read about in your forum?
Any thoughts on this one ?
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PostPost by: rgh0 » Tue Jul 20, 2004 11:32 pm

The pressure relieve valve in the standard pump is set at a nominal 40 psi. With good bearing clearances and good oil you should expect the pressure to be around 30 psi plus at idle and to go up to 40 psi and stay there any speed above idle. If the guage reads a max of 35psi it could be a pump relief valve that is a little low or a guage that reads a little low or some combination of both.

The fuel tank is hard to fill to the very top but a voltage regulator problem could be contributing to this also.

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PostPost by: davidcroft » Wed Jul 21, 2004 8:38 am

Hi Paul

You could be describing my car - apart from the 130/5 bit.

I've got a '71 +2S and the pressure gauge does pretty much the same thing. If anything mine reads a bit lower - and sticks at about 30, hot, cold, at idle, at 5K rpm. I've kind of given up worrying about it, although the next time it goes in for a service I'm going to ask the mechanics to fit an external gauge to check the reading.

I've got an oil cooler too - maybe a common thread here? I don't know anything about it as it was on the car when I bought it.

As fo the fuel consumption, I've kind of given up worrying about that too. Around town with a heavy right foot, the thirst is heinous. On motorways and A roads, even with a 4-speed, I've had 350 miles plus from a tankful.

Well, I say a tankful, but who knows...I've never managed to get the fuel gauge above 3/4 full either.


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PostPost by: kevin » Wed Jul 21, 2004 2:11 pm

Hi Paul

Early +2 - recenlty rebuilt engine - I get a constant 40psi -2psi +5psi.

However - I suspect the electrical sender to be faulty - When I got the car, the lucar connector on top was broken off - I resoldered a new one on, but I suspect that the heat may have damaged the internals.

As for my Fuel gauge it always reads full after filling up within a two - three inches of teh top of the neck. I do have a new VRM fitted though.


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PostPost by: Stu » Thu Jul 22, 2004 5:15 pm

I haven't got a lotus, but have a question invloving OIL pressure.

I have a modified 2 litre Pinto engine. 38 DGMS carb and stage 2 head. My oil pressure when cold is 50 PSI and if i drive down the road it is just above 50. when the engine warms up the driving pressure is constant at 50, but when I stop at a junction the pressure drops down below 20 on the gauge. moving away from the junction the engine seems hestiate. As soon as the throttle is pressed the presure goes back up to 50.

Any advice??????
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PostPost by: paros » Thu Jul 22, 2004 6:33 pm

As to effect of oil collers I can add something here! The Elan with a 9 or 10 row gave a pressure drop owing to the restricting effect of the matrix. Going to 16 row another 5 or 10 psi.
Also note the electroc gauges need the voltage stabilisers working properly to be accurate - and the snsor I think is no longer available that is compatible with the Elan gauge. So don't believe the instrument look at the pressure drop or increase. I have 2 mechanical gauges and they show a good 5 psi difference. Yes I did use to work for Smiths!!!!!!
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PostPost by: JACKJABBA » Thu Aug 12, 2004 6:12 pm

Stu, sounds about right from what I have been led to belive. The Twin cam can drop as low as 15 psi on idle and then go back up to 35 once on the move again..

Seem to have read somewhere that oil coolers are not recomended for standard engines and should only be fitted to performance ones? I will try and look up the article.
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PostPost by: type36lotus » Fri Aug 13, 2004 1:56 am

Jack, that is pretty much the same thing the mechanic (Steve Smith - Twincam Sportscars) who rebuilt my engine said to me. An oil cooler is not needed and was the reason for the slightly lower oil pressure. I am planning on removing it when I perform my next oil change.
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PostPost by: 1964 S1 » Sat Aug 21, 2004 2:16 am

For Years my gauge has read 12 to 14 at warm idle, goes up to 25 while accelerating, stays there while cruising. Then I tap on the gauge and it reads 38, max. Car runs great, no scary noises.
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PostPost by: garyk » Sun Sep 05, 2004 10:16 pm

I've had my +2 S130/5 for just over a month and only noticed that it had an oil cooler this morning. The clock has been swapped out for an oil temperature gauge which I assume is connected to the cooler.

I get about 42 PSI while the engine is warming up load then about 38 after it's warm. At idle, it's more like 20.

I assume that I have nothing to worry about. Would you let me believe different?

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