Oil Pressure Gauge !!!

[MM]

Hello All,

Just a quick question for those in the know !

About 4 weeks ago i had a major service on my 300SL (j reg), prior to having this done i noticed that occassionally the oil pressure gauge use to sit at about 1.5 in idle and shoot up to 3 when i put my foot on the gas pedal.

Since having the service i have not driven my car more then 30 - 40 miles, it spends most of its life on the drive way. Anyhow this morining i drove to work and noticed after about 5 minutes of driving the oil pressure guage drops to 0 - thats right "ZERO" when ideling, it shoots up to 3 when you move off - but anytime you come to a stop - it goes back to 0 !

Now then - the oil light does not illuminate and there is no knocking or tappet noise coming from under the bonnet. I've just taken it for another quick drive and found the same - i was hoping it was down to the cold start etc - but appears not..........any ideas ?

Normally i would not need the car on a daily basis - but of all the weeks in the year - i need it for the next two weeks - daily....

apart from this - it drives like new (since having the service)

any suggestions - ? need i see my bank manager for a loan ???? (pls say NO)

any comments (positive / constructive) most appreciated.

Happy new year to all

MM

 

[Silver Arrow]

I had a similar experience with my Suburban. It was the sender unit.
Perhaps a check on the connection, just to see if the operatives have disturbed it.

 

[malcolm E53 AMG]

Does this garage usually service your car. It sounds like you may be seeing lower pressure on the guage because the car has been filled with a lower viscosity oil. I'm no expert but I would imagine this would give a lower reading at tickover. I would imagine the engine protection is not affected providing the oil used is within MB guidelines for the car.

With older engines with hyraulic tappets I found the engine became more noisy with the newer synthethic thinner oils, which I wasn't very keen on, but supposedly had no detrimental effect. Its probably worth talking to the garage about the reading.

 

[MM]

Thanks for your input gents,

I have used this garage in the past - but this is the first service i've had to have done whilst the car has been in my care, the garage is a merc specialist - so i would imagine they've used the right oil.

I will book it in nexrt week - and until then it wont be on the road (cant afford for it to go too wrong) - any other suggestions - more then welcome - but as soon as i find out what it is - i will let others know !

Thanks

MM

 

[anchorage77]

mm zero oil pressure would make me check that 'A' there is oil in the sump, and 'B' the correct oil filter was fitted. If that is OK then drive it back to the garage and explain your concern , if its NOT ok get them to collect it on a pick-up!

 

[television]

The normal way to deal with this is to screw a presure gauge into the oil gallery and it tells all. The senders do go down and are cheap to replace, as the light is not coming on that's good news and that is on a different sender.

Malcolm

 

[996jimbo]

My money would be on Malcolm210 above and the fact that you have decent oil in the car now hence pressure drops at idle.

I would guess (and it's only a guess) that as long as you have the correct amount of oil and that pressure comes up to scratch when you accelerate then you shouldn't worry.

We've got an old Alfa and that shows the same as you describe - it's not using oil and the head gasket is OK so I'm not worried.