Oil pressure warning light and guage 4200cc

G

gerlad

Junior Member
Messages
37
My oil pressure gauge was functioning perfectly well but I noticed the occasional oil warning light flashing and the gauge itself dropped ever so slightly causing the light to flash. This was intermittent. I had the oil sender unit replaced (oil pressure checked and was ok) but just after I picked it up the gauge started working like a windscreen wiper with the corresponding warning light flashing. It settles down when it gets warm, but will still flash occasionally. In a further development tonight I noticed that the fan stayed on and I got 3 groups of two beeps from somewhere under the dash board (foot-well area) at intermittent periods. Also when I stopped the car and tried to restart it again it didn't want to play ball but eventually started on the second attempt which is totally out of character. There are no strange noises from the engine (apart from the vibration of the fan) and no warning lights apart from the intermittent oil pressure warning light already mentioned. Oil is up to the max and a new filter has been fitted. Any comments/advice welcome!
 
conaero

conaero

Forum Owner
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34,633
Multiple electrical issues usually have a common cause.

I had this when I got my GS. It turned out to be something as simple a loose battery terminals. The terminals were secure but the piggyback cables had worked loose.

Also turn the battery off whilst you are doing it for at least 20 mins to let all the electrical systems fully discharge.

Your oil gauge does sound goosed and emulates standard behaviour of when they fail, just change it.
 
outrun

outrun

Member
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5,017
I 2nd Matt's theory that it may be the battery terminals after being worked on. They just don't like being at all loose.
 
StuartW

StuartW

Member
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9,320
I agree, it had just been the gauge reading I would have suspected the sender which are notoriously fragile but it sounds like it's more involved than that. Good luck in getting to the bottom of the gremlins
 
Kookaburra

Kookaburra

Junior Member
Messages
32
My 4200CC 2005 started doing exactly what Gerlad's oil pressure gauge and warning light did. I'm driving along at medium revs, everything is settled nicely and then suddenly the oil pressure needle drops right down and the red pressure warning light comes on. After a few seconds it goes back up to the top. Meanwhile the engine makes no untoward sounds - I checked by sticking my head out of an open window... Anything related to oil pressure on this expensive engine scares me, but my instincts tell me it's either 1. dodgy gauge, or 2. something electrical that's worked loose or failing, or 3. all of the above. I'll try disconnecting the battery terminals and leaving it 20+ minutes but anyone else had a similar issue and managed to resolve it?
 
philw696

philw696

Member
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25,503
Its the sender unit that has failed right at the back of the block just above the bell housing.
Easy enough to do if you're technically minded.
I favour removing the inlet manifold and giving everything hard to see a good visual and clear out detritus.
 
conaero

conaero

Forum Owner
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34,633
You will need a crowfoot spanner think it’s a 19 or 22mm. It’s a pig of a job without removing the plenum but just takes patience and a lot of swearing.
 
Zep

Zep

Moderator
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9,296
Its a 24mm crows foot you will need and the swearing is mandatory. This size of crows foot is quite hard to come by, I cut down a spanner and had a 3/8" drive adapter welded to it.

The part number of the sender is 135940 and they are about £75 plus postage.

I have made up a few adapters to allow a standard sensor to be fitted. It saves about £20 on the original and if it fails again it is both easier to change and a lot cheaper to buy a standard size sender.
 
conaero

conaero

Forum Owner
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34,633
Thanks Zep just been out in the garage and yes it's a 24. I had to grind the crowfoot spanner to half it's thickness so it slips under. If you want a lend PM me.
 
Zep

Zep

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9,296
CatmanV2 said:
I thought yours was first? :)

Been too long, chap. We need to catch up

C
Click to expand...

I changed mine to a standard one and in the process decided that it was a good idea to make an adapter. Then all I needed was a patsy ;)

There are now three or four in cars.

It has been, I will message you next time I am in London and we can meet up.
 
Zep

Zep

Moderator
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9,296
Conaero said:
Thanks Zep just been out in the garage and yes it’s a 24. I had to grind the crowfoot spanner to half it’s thickness so it slips under. If you want a lend PM me.
Click to expand...


You have been out to the garage? It looks too cold up here for that sort of thing!
 
CatmanV2

CatmanV2

Member
Messages
48,813
Zep said:
I changed mine to a standard one and in the process decided that it was a good idea to make an adapter. Then all I needed was a patsy ;)

There are now three or four in cars.

It has been, I will message you next time I am in London and we can meet up.
Click to expand...

Cool!

C
 
BennyD

BennyD

Sea Urchin Pate
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15,006
Zip, if you have any spare adaptors could I buy one please? I’ll fit it the next time my sender goes, and it will!
 
Zep

Zep

Moderator
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9,296
BennyD said:
Zip, if you have any spare adaptors could I buy one please? I'll fit it the next time my sender goes, and it will!
Click to expand...

Zip?

Of course, let me know when you are picking up your car from CL and you can either pick one up or I'll meet you there.
 
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