Oil Pressure gauge reading slow

[m100sandra]

Just wondering if its normal, When the Elan is parked up for a couple of days the oil pressure gauge seem really lazy to get to where it should, any other time its fine, i.e. If i use it on a morning & then start it up after tea the gauge will show the correct pressure straight away, but leave it a couple of days and it climbs really slow on its 1st start up. Oil is Millers CFS 10w50 fully synthetic http://www.millersoils.co.uk/automotive ... Motorsport K&N oil filter, 16000 mls.

Thanks
Sandra

[hatters]

Could it be the Oil Pressure Relief Valve Spring ??

[Brit-Car-Nut]

More important: Is it the pickup screen is clogging up?

[Specky]

Just wondering if its normal....

Sadly not,

Bearing in mind the various variables and properties of engine oil and the condition of your engine, outside air temperature.... Etc

Upon turning the key and idling on a cold engine... 5-7 Bar

Upon turning the key and idling on a hot engine...2-2.5 Bar

The needle movement is all but instantaneous as you turn the key.

Always do the simple stuff...

Have you got enough oil in the car, a really low oil level will give your symptoms.

Give the car an oil and filter change... Have a look what's contained within the oil..you may want to try a slightly different specification of oil, something slightly thicker, semi synthetic... (horses for courses and all that)

Suspect the oil pressure gauge itself and even the pressure switch... I'm trying to recall if Elanscan reads oil pressure... But if it does... Cross check the corralation between Elan scan and the gauge? Could it be just an indication issue...

I hope that helps a little...or at least gets you going in the right direction.

TTFN

[m100sandra]

Thanks for the replys, Oil pressure is fine, although the garage did a full sevice, my son did a oil change (millers & K&N filter) to be sure.
Searching the web i noticed some others have the same sort of thing (non Lotus) http://www.bobistheoilguy.com/forums/ub ... ber=958438 Similar symtoms as i have

[tigerdog]

I'm with Brit-car-nut on this one. Just trying to parse things logically: as Specky says, the gauge should read instantaneously. It's possible the pick-up screen is clogged. After the car sits and oil drains out of the galleries, the next start requires a big bunch of oil all at once for the initial fill. A clogged screen would limit the maximum flow rate, especially when the oil is cold and therefore more viscous - harder to suck through the restricted screen. Once the engine is full of oil, maintaining pressure requires less volume. Combine that with thinner oil that would flow through any restrictions more easily and everything would seem normal. nsr250 had a similar but not identical problem and resolved it by cleaning the screen. See this thread.

[m100sandra]

Just another thought What psi should the oil pressure light come on or go off? ignition on the oil light is on, start the engine & its straight off even with the sleepy gauge when its been stood for a while, if there was a blockage wouldnt the light also stay on for a while indicating low oil pressure.

[Specky]

Strange... I replied to this early this morning..

It's about 1 Bar from memory.

TTFN

[norman lovie]

this is one of them things that you need to assume worst case - until proven otherwise - obviously because of consequence, however if you've done a fair amount of miles with this observation with no mechanical issue then it does give some confidence, a turbo and shell bearing crank don't last long if oil feed is poor and if your getting good solid pressure when hot - you can atleast be confident that it hasn't as yet run dry on them

I would
1) park it until otherwise proven
2) get an alternative pressure gauge ( don,t use the original sender) onto the car and simulate the same conditions = prove its gauge or real
3) if its real, and as it hasn,t caused a mechanical failure - yet - then you've got good advise ref: the screen pick up + relief valve sticking as likely culprits

eh! welcome to being a new owner, these cars do like TLC

[m100sandra]

Re: my last post, Isnt the oil pressure light going off imediatly on start up saying that all is well just thinking that the lesser cars here such as VX220 Turbo's, Noble M12's rely on the oil pressre light only with no gauge (as standard).
.

[tigerdog]

Re: my last post, Isnt the oil pressure light going off imediatly on start up saying that all is well just thinking that the lesser cars here such as VX220 Turbo's, Noble M12's rely on the oil light only.

It means the engine is generating sufficient pressure to avoid catastrophic failure, not that all is truly well. I've always understood that by the time the pressure light comes on, at least while driving, it's too late. The gauge is more of an early-warning system and I'd feel better if the sluggish gauge had an explanation. If nothing else, make sure the car has a very gentle warm up until full pressure is reached and drive gently until proven.

[m100sandra]

Just a follow up on my 1st post, What i have learnt with the gauge is: If i turn the ignition on & leave it without starting the engine for a couple of minutes the gauge isnt so lazy,With a instant start up as well as been slow to get upto full pressure its also slow to come back down from cold if i swith the engine off, Still a bit puzzled why leaving the ignition on for a few mins should make a diference Ignition on and the gauge is below the zero, after a few mins with the ignition on (Engine not started) it will slowly move up to the zero, start the engine and it will move up to over 5 bar + fairly quickly, puzzled Any thoughts?

Sandra

[tigerdog]

bad earth/grounding and/or corrosion in the gauge +12V supply? Anything that would inhibit free current flow in response to the sensor would compromise the gauge behavior. Our cars being 20+ years old, especially those in damp environments, could likely benefit by every wiring connector getting a spray of contact cleaner and a couple of disconnect/reconnect/wiggle motions.

[Rice crispy]

My gauge sometimes fluctuates but only for a second. Assume its a wiring issue as it appears to only happen when warm. Am i correct that the sender connection is just above the oil filter and points towards nearside wing ?

[norman lovie]

bad earth/grounding and/or corrosion in the gauge +12V supply? Anything that would inhibit free current flow in response to the sensor would compromise the gauge behavior. Our cars being 20+ years old, especially those in damp environments, could likely benefit by every wiring connector getting a spray of contact cleaner and a couple of disconnect/reconnect/wiggle motions.

that there is the answer - and hopefully it's good news: you have clear evidence now that your gauge is mafunctioning due to an electrical fault: OK this does not fully rule out actual oil pressure issues but you would be unlucky to have both separate failure types occuring at the same time

whats happening is the current is drying out - reforming - the connection, so the resistance caused by a poor connection drops and the gauge, - which is a resistance meter - not an bourdon tube pressure meter - then comes back into callibration

rpeating comment above, this is a message for you, the gauge is a benign issue - if you suffer the same with an engine management sensor then this will have significant impact on the engine performance.
If you were to buy / use the data logger: then you can be building up data from the sensors - a bit like a health check - then - if you start to see changes on any of the engine managment sensor inputs - for no obvious reason - then this is telling you -there is other electrical connectors needing some TLC

[tigerdog]

Cleaning and wiggling connections is also a nice, no-brain activity for a Saturday afternoon. Unplug one at a time, clean, refit and move on. Plus, even if it doesn't fix any current problems, it can stave of future issues so there's no harm done.

[HJ2]

A friend of mine has problems with his oil pressure as well.
I suspect a grounding problem somwhere, so i'll check that first.

If not: What do i need to do to get to the pickup and the relief valve? Are they both under the sump?
I have not removed a single prongeron before, so i am a bit nervous to do that. Any good directions would be welcome.

Also is there a rockauto part to replace the sensor if that is the culprit?


HJ2

[Fredjohn]

A friend of mine has problems with his oil pressure as well.
I suspect a grounding problem somwhere, so i'll check that first.

If not: What do i need to do to get to the pickup and the relief valve? Are they both under the sump?
I have not removed a single prongeron before, so i am a bit nervous to do that. Any good directions would be welcome.

Also is there a rockauto part to replace the sensor if that is the culprit?


HJ2

HJ:

Removing prongeron is less daunting than I imagined: had to do it after I cracked the sump in Ypres this year......... The oil pick-up is then visible once sump is removed.

Important thing is to make sure the suspension does not move when prongeron is detached. Use 2 axle stands to support car and 2 more under hubs to hold suspension steady whilst apart. This way nothing should move and all bolts should just slide back in. They did for me anyway!!

Back on topic though: my oil gauge and voltmeter behave differently depending on general ambient temperature. Both read slightly higher when cool, and both drop slightly when warm. eg charge voltage reads approx. 13.8 cold but 13.4 when warm. (ambient not engine temps). Seems bizarre but I think it may be something to do with electrics and/or voltage regulator. Actual oil and charging are fine. (I think!)

John

[HJ2]

Okay, thanks!

That sounds easy peasy then