Low Engine Oil Pressure

[MIKE236]

Hi All.
For the last 2 weeks I have been having low oil pressure readings and wondered if it has anything to do with the age of the car or other some sinister thing waiting to happen. The readings are as follows:
On start-up (early morning): 3 (max)@900rpm
At Op Temp 80C+ : 1.5@750rpm(In Park)
At 60Kmh@2000rpm: slightly below 3
At 50kmh@1800rpm: 2.5
At 40kmh@1500rpm: 2
At 30kmh@1300rpm:1.5
In D@700rpm(car stationary) :1

The only thing I noticed is that my engine oil is only 3/4 within the min and max levels. There are no leaks visible at this point and the car still runs smooth. Can anyone offer some advice in this probelm please. Thanks in advance for any help or advice offered. Regards.

 

[NormanB]

Yip - it looks a shade low to me too, although I have the same car (with very similar miles yours =150K). I am not an expert on these matters by any means.

When my engine is at operating temp and idle pressure is 2.0 but as soon as I pull away the pressure rises immediately to 3.0 bar (at say 1000 rpm).

Now it could be that it is instrumentation but the fact that yours indicates 3.0 bar when cold would lesson the likliehood of this. But it must be worth eliminating that, it cannot be too expensive (relatively) to have that checked by an indy.

If not that then it may well be you are losing pressure internally thro' increased clearances (bearings - eek) - hey I am not sure. Hopefully Andy Gayle/Piestore will see this and advise.

Keep yer fingers crossed.

 

[andy_k]

the obvious suggestion would be try an oil and filter change and see if that improves things - could be just the oil needs replacing

Andy K.

 

[MIKE236]

Thanks Norman and Andy for your input. Actually had the filter and Oil Changed about 2000kms ago and had used Shell Helix Ultra (fully synthetics).

Norm..when I press on the gas..it'll still go up to 3 but once I start to decrease speed from say 70kmh to the abovementioned speeds then it starts to drop. I am particularly worried that constantly low oil pressure might hurt the engine??

Andy..will follow your advice and see whether the engine oil and filter change will help. BTW, if that doesn't cure it, what do you think will be the most likely culprit and which part of the engine will tend to be hurt most.

Thanks again guys for all the help.

 

[sunil sood]

i would suggest you try a genuine oil filter from mercedes together with a 10w/40 oil-that is what i use in my car.


quote="MIKE236"]Thanks Norman and Andy for your input. Actually had the filter and Oil Changed about 2000kms ago and had used Shell Helix Ultra (fully synthetics).

Norm..when I press on the gas..it'll still go up to 3 but once I start to decrease speed from say 70kmh to the abovementioned speeds then it starts to drop. I am particularly worried that constantly low oil pressure might hurt the engine??

Andy..will follow your advice and see whether the engine oil and filter change will help. BTW, if that doesn't cure it, what do you think will be the most likely culprit and which part of the engine will tend to be hurt most.

Thanks again guys for all the help.[/quote]

 

[MIKE236]

Low Engine Oil Pressure-UPDATE

Hi again to All!

Managed to get the pressure checked. First changed the oil and filter. Improved a bit but was still on the low side especially at idle in D, reading improved to about 1.5 bar. Then proceeded to check the instrument panel connecter and engine oil pressure sensor. Engine side..OK, instrument side connection dodgy and rubber connecter cracked. Had to replace the connector.

Anyway, after running the car out of town for two hours and back, pressure remained much higher than before. Now at idle in D=slightly above 2 and 2.5 in P. Guess thats as good as it gets for a car that age. Even in stop go traffic, hardly ever reach 1 in D at idle (as opposed to before). Keeping my fingers crossed that it won't happen again.

Thanks guys for all your input and advice. Cheers and regards.

 

[NormanB]

Mike
That sounds a lot better to me, in sum, as long as you have 3.0bar while driving dropping to 2.0bar at idle is (I understand) par for the course.

 

[Andy]

Hi

By the sounds of things you are ok. But on some of these older cars I would use a little thicker oil, say 15/40. This may help. If not remove the sump & give it a good clean. You would be supprised by the amount of sludge with can congregate in there and not be removed on oil changes.


Good luck


Regards

Andy@ www.mercedesservicing.com

 

[MIKE236]

Thanks Andy for that piece of advice. Actually, what you say is true. This time around the Indy Specialist removed the sump and Gawd!! what an awful load of sludge sitting there. I myself am surprised as I had been regularly servicing it at every 5k's and did not think that the sludge build up could be that much.

Regarding the oil..yes..the guy recomended 10-15W oils, not 5W as in most synthetics. Guess have to stick to the mineral stuff.

Norman..you were right as well regarding the instrumentation. The guy did not think it was anything to do with the instrumentation until i asked him to take a look.

The lesson..if the oil and filter change does not work, check the instrument panel. If that doesn' work as well....run to your computer & seek help on the forum..tee hee.

Thanks again guys. Cheers and regards.