oil level indicator keeps changing

MissyD

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(Apologies if I haven't used the correct terminology)

Not noticed this before, but when I was driving home this morning I noticed the oil level indicator kept changing.

It is normally on 3, but when I slowed down and came to a stand still the level dropped to between 2 and 2 and half, when I accelerated again it went back up to 3. It kept doing this all the way home (journey of about 35 minutes).

Once I was home I checked the oil level on the dipstick and it was ok (see pic).

Is it normal for the indicator to do this, if not, what does it mean please?

SS101553.jpg

SS101556.JPG
 

Dosco

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Pretty dip stick...

...is that:D

It may be due to voltage fluctuation (problem with the voltage control device) causing the instrument to surge as your alternator output increases as you accelerate.

May not of course, Malcolm I am sure will be able to throw some light on it for you. In the mean time keep a check on the dipstick at least you know that will be accurate.
 

Alex M Grieve

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(Apologies if I haven't used the correct terminology)

Not noticed this before, but when I was driving home this morning I noticed the oil level indicator kept changing.

It is normally on 3, but when I slowed down and came to a stand still the level dropped to between 2 and 2 and half, when I accelerated again it went back up to 3. It kept doing this all the way home (journey of about 35 minutes).

Once I was home I checked the oil level on the dipstick and it was OK (see pic).

Is it normal for the indicator to do this, if not, what does it mean please?

Good news Sarah,

That is entirely normal. Full reading when you rev the car or when driving along, but the reading drops when stationary or on tick over. Picks up again promptly when you drive off.

Like lots of normal things, you tend not to notice them usually - then when you do it can be worrying!

No problem this time, but don't stop noticing. Red lights, for example, tend to be bad news - and there would be a red light on your dashboard if the oil pressure failed. In which case, stop and get help would be the best course for any of us.
 

Jay Gee

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Missy D-hope you noticed the subtle reference to oil pressure in Alex's post above.Your gauge actually shows oil pressure,not oil level.It is normal for pressure to fluctuate with engine revs.Keep looking though,and get any significant change investigated.Keep checking the dipstick regularly(nice clean oil you have,BTW). That oil pressure sounds OK to me.Why did MB ever get rid of oil pressure gauges?Seeing the needle up against the max.stop like that gives a feeling of confidence IMO.
 

rf065

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Your oil pressure looks fine & your oil looks very clean too, had a service recently?

Russ
 
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MissyD

MissyD

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Your oil pressure looks fine & your oil looks very clean too, had a service recently?

Russ

Thanks for the reassurance guys.

I had a service in Sept 08 and had a new oil filter, air filter and oil change
 

rf065

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Thanks for the reassurance guys.

I had a service in Sept 08 and had a new oil filter, air filter and oil change

I guess you don't do a lot of miles?

Russ
 

roofless

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she is right both my 124s sit at 3 all the time
 

Dosco

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Wrong

...is that:D

It may be due to voltage fluctuation (problem with the voltage control device) causing the instrument to surge as your alternator output increases as you accelerate.

May not of course, Malcolm I am sure will be able to throw some light on it for you. In the mean time keep a check on the dipstick at least you know that will be accurate.

Got that WHOLLY wrong didn't I - should have looked at the pics then (perhaps:rolleyes:) I might just have twigged it - not too old to learn:Oops: Sorry Missy
 

television

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The chances are it will need a new oil pressure sensor, its on the side of the oil filter housing
 

television

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Got that WHOLLY wrong didn't I - should have looked at the pics then (perhaps:rolleyes:) I might just have twigged it - not too old to learn:Oops: Sorry Missy

Dosent do me much good when I look at the pictures of Missy D either
 

Dosco

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Does that suggest you expect full oil pressure on tickover Malcolm?

....I need the pedal to the metal nowadays to get the pressure up on my gauge, if only tickover was an option...;):lol::lol:
 

HERBIEMERCMAN

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hi missyd, i wish my two daughters cared like you do about the upkeep of their cars,

however i agree with what most of the members have pointed out to you including the point about electrical voltage, although this affects all the guages, all modern gages are just amp or volt meters working on an electronic senders, usually sintered measuring temperature or pressure which alters the resistance of the sender and passes more or less current to the measuring device.

a new engine with no wear in the oil path system, and a good multigrade oil will show some difference from tick over rpm to high revs, but the greater the difference the more wear you have. prior to multigrade oils the difference was even greater once the engine reached the running temperature.

for the cost of the oil sender i would change it as malcolm advised as unless your engine is high mileage 100,000 + then the amount of wear to cause large fluctuations in my experience would be associated by a noisy engine, bearings knocking. the dip stick is good thing to keep an eye on as several have outlined to you, but you can have new oil and a full dip stick on a completely worn out engine it is also the case that oil pressure will hold up usually untill the last drop of oil is in the engine.

i have a boat with two merc. engines from start they go to 50 psi and stay there no matter what the revs are. i am just explaining how the system works but feel that you do not have a problem, and it can be checked and fixed very easily. best wishes. herbiemercman.
 

roadhog

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Why are you lot advising changing the oil sender when it quite obviusly works? :confused:

If it's only just started doing it, it could be that a different grade of oil was used? What did your man put in MissyD?

I'd be more worried if the pressure wasn't fluctuating and sit at 3 all the time. That's the time to look at senders, gauges etc. The gauges do stick, mine does occasionally. If the pressure sits at 3 after you've turned the engine off have a look at the over pressure switch on the oil pump. Or thump the dash which helps on my car, it's also a lot easier than taking the sump off. :rolleyes:

Anything between 2 and 3 at idle or low revs has got to be healthy.

There's nothing wrong with the oil pressure in that engine. The End. :)
 

roofless

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it's just a quirk of this model they just sit at 3 all the time as it's more a indicator than a true pressure guage & will prob be just a iffy sender unit or guage & not a big prob......... but i would say have it checked just to be safe
 

roadhog

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it's just a quirk of this model they just sit at 3 all the time as it's more a indicator than a true pressure guage & will prob be just a iffy sender unit or guage & not a big prob......... but i would say have it checked just to be safe

They don't. Honestly. Not. :rolleyes: If yours does then there's something wrong with it.

"More an indicator than a true pressure gauge" ? :confused: Come again? OK, so it's perhaps not calibrated but that doesn't mean it doesn't indicate correctly.

Oil pressure will vary with engine speed, oil pressure varies -> different reading on the gauge. What could be simpler?

If the gauge fluctuates at steady rpm, you've got a problem. If the gauge doesn't move with changing revs (assuming correct oil, at operating temperature etc), you've got a problem. If the gauge doesn't reach 3 at medium to high revs, you've got a problem.

If the gauge moves with the revs and doesn't drop below 2 at idle (as is the case here unless I misread the OP) then YOU DON'T HAVE A PROBLEM !

As you were. :)
 

kth286

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Sarah

If I may comment on the coolant temp.

It seems low bearing in mind you have just stopped after a 35 mile journey.

Does it normally go over 80 on coolant temp gauge when driving ?
 

Alex M Grieve

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Sarah

If I may comment on the coolant temp.

It seems low bearing in mind you have just stopped after a 35 mile journey.

Does it normally go over 80 on coolant temp gauge when driving ?

Good point David - I thought that too, but did not comment. I would expect just a smidgen over 80 when the engine is warm.
 


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