Oil pressure light - The one you never want to light up!!

When starting the Alpine this morning the oil light lit up on the dash. Both the oil level gauge and the oil pressure gauges stayed on zero. There were no nasty noises from the engine ( yet ! ) Does anyone think that the oil pressure sender unit could be faulty or the oil pressure relief valve be stuck. Is there a history of oil pumps breaking up . Any thoughts of advice would be welcome. The engine was only run for 30 seconds after the light came on and then shut down for its own good.

Hi Chris,

Sorry to ask, but is there oil in it ok?

If yes then safest method is to remove all spark plugs to reduce the pressure on the big ends. Then fit a proper oil pressure guage in to the oil way, there is a plug on the nearside around the turbo oil supply. Crank the engine for a max of 10 sec, should be showing oil pressure by then.

If any concerns remove the oil filter and prime the oil pump with an oil can first. Very messy work!

Thanks for the reply Richard. The oil is good has only covered 500 miles since the top end rebuild. I will get the car onto a ramp on monday and connect a pressure gauge & see what we get. Do these engines have any history of pump problems ?

Did the oil pressure needle move at all ? Check the wiring at the sender .One of the wires if earthed to the block should switch the oil warning light on .
Do not attempt to start , just switch to the 2nd position and see if the needle moves slightly .It should move to just below the start of the scale .
As Richard says , crank it and check with a proper gauge .
I wouldn't run it at all until you can get a proper gauge plumbed in if the senders are working .

Mine did this, only a few weeks after getting it.
Turned out to be bad connections on the sender unit.

Some new spade connectors, and some switch cleaner and all was working.

Sound advice above. Removing the plugs to remove compression forces from bearings. Might be an idea to remove the fuel pump fuse as well.
I saw someone spin an engine over once without plugs, and flames shot out of the plug holes, where the leads were still close to the plug hole and ignited the fuel vapour.

Many thanks for the info Gents. Does the one sender feed both of the oil dials as well as the oil warning light. ie am I looking for more than one sender to check and clean.
I removed the the air con pump and pipework last week & I am guessing that I have disturbed some wiring.

It'll be one combined with two terminals or a couple with an extension takeoff port for the light and pressure sender on the end both with only one terminal .
Either way they are in the same place on the block next to the oil filter .

[mettersl]

Chris,
I don't know which type of A/c compressor install you have (left or right on the car) but on My 610 (A/C on the right side of the car) its possible to mix up the bolts and short out the oil pressure light sender (short to earth = light on).
I had this happening on mine after I removed the A/c pump and then after a mile or two the oil light came on- but in my case the gauge stayed working so I was a little less worried.
Paul Sage sorted this for me- he found that I had managed to swap a long and short bolt, so when the car got hot, the bolt touched the sender (or maybe the wiring), either way swapping the bolts back and some attention to the wiring sorted it.

Good luck, its probably just a minor problem, nothing to worry about yet.

Lee

Many thanks for all the advice so far. The oil pressure test agreed with the dash gauges -No oil pressure ! . After priming the pump & getting the same test results & a conversation with Richard ,I have decided to remove the timing cover and have a look at the pump & pressure relieve valve. Removal of the sump confirmed that all was well at the bottom end & that the oil pick up was clear & there was no debris in the pan. I need to finish of a few client cars so hopefully I can begin stripping the engine later in the week. Am I best going to Renault for the gasgets or is there a better source?

Get them from Renault, not to badly priced and they fit first time.

Good luck with your strip down.

Got it all apart today. The oil pressure relief valve was stuck open ! Plan to look for a new pump next week & bolt it all together during the week & see what happens when the key is turned. Hopefully no damage .

Good stuff .
At least you spotted it early and found the problem so fingers crossed it'll be OK for you .

Great new Chris!

Reanult are quoting £180 for a new pump with relief valve. Does anyone else have a supplier that I can try for a better price. Can I hone & re-use the existing pump? The sticking could have been caused by a small particle of debris in the valve. The piston & bore look in good condition !

It's the smaller height rotors you have right? I'll go measure, and post up. The later block engine (cross-bolt one) has the same as the 3ltr 610, Bi-Saf and later std 3ltr n/a PRV which is bigger.

Is the block undamaged? Can you post some picks?

There are a couple of versions of the pressure relief piston, not sure what I have about. But I may be able to find you v good serviceable parts; if it's scored I chuck mine. I only have one 2.5 early block to build so may have some spares. The piston you can polish, but usually scored and rubbed over at the top land as the piston tilts in the bore. I guess you could re-hone, but you will need to find a suitable piston to match.

Simon Auto sells them, but as you say not cheap.