oil pressure 230ce (w123)

[xan]

When I start up the engine of my '83 230ce from cold, the oil pressure needle goes up to 3. When the engine is warm & idling, the needle drops to about 1.5, and then goes back up to 3 whenever I accelerate. Is this normal? It seems to be dropping lower than it used to do. Are there any possible reasons for this, and generally how often should I be changing the oil?

Thanks
Xan

 

[Myros]

depends on when you last changed it

and what you are running in it at present.
If the pressure at warm idle is dropping, it might be a sign of oil pump wear. You could shift up to a slightly thicker oil in a bid to restore the pressure, but try a change with the grade you are running now/or the recommended grade and see what happens. search here on OIL and be surprised by the depth of debate.

 

[TimN]

1.5 is perfectly reasonable in my experience. Oil pressure drops when the engine warms up because of a change in the viscosity and then will drop further on idle simply because the pump is not operating as fast.

Oil pressure loss is created by wear in the moving parts such as crank shaft or cam shaft which are the biggest culprits. The test to look out for is any unexplained new noises such as a deep knocking sound. The cross-sextional area of the crankshaft gradually changes from a circle to a ellipse over time. This creates gaps that the oil can flow out without resistance.

Other areas for oil pressure loss are a stuck oil pressure relief valve, wear in the oil pump and leakage from the cam chain tensioner or indeed debris clogging the oil strainer in the sump.

So long as you don't have any nasty noises it doesn't sound as though you have much to worry about

 

[tom7035]

1.5 is perfectly reasonable in my experience. Oil pressure drops when the engine warms up because of a change in the viscosity and then will drop further on idle simply because the pump is not operating as fast.



So long as you don't have any nasty noises it doesn't sound as though you have much to worry about

I agree with TimN. On some older cars it is quite usual for pressure gauge even to register zero on idle, so long as pressure registered immediately engine revs. increased. Trying a 'thicker' oil may register more pressure, but this would only be a psychological cure!
I would't worry.

 

[sunil sood]

When I start up the engine of my '83 230ce from cold, the oil pressure needle goes up to 3. When the engine is warm & idling, the needle drops to about 1.5, and then goes back up to 3 whenever I accelerate. Is this normal? It seems to be dropping lower than it used to do. Are there any possible reasons for this, and generally how often should I be changing the oil?

Thanks
Xan

.

i would replace the oil filter as this can affect oil pressure.

a good quality oil as per the car specifications and oil filter cahnge once a year is mandatory to mantain a longlife of the engine-

 

[stwat]

Mercedes recomend you change the oil every 6000 miles but as mine has now done just under 130.000 miles, i change mine every 3000 or there abouts just to be safe. If you have'nt changed your oil for a while, then that could be why the pressure is reading a bit lower than normal. Oil brakes down(gets thinner) as it gets older baisicly. But as has been said, 1.5 is nothing to worry about mate.

Stu

 

[pascal]

As long as it does not drop below 0.3, and increases on acceleration, your engine is not jeopardized. 1.5b on warm idle is quite normal for 230 engine.

 

[MW]

The curious thing is that if you did not have an oil pressure guage like most new cars, you would have no concern. Yours looks very normal to me. 3 bar when running is fine. 1.5 on tick over is good. Change the oil every 6k or less. Use a genuine filter with a non return valve, about £3+ at Eurocar parts.

 

[stever]

The handbook for my w123 280CE lists minimum oil pressure as 0.3 bar, so you have nothing to worry about. The main thing is that pressure increases quickly to 3 as soon as you accelerate or start from cold.

 

[xan]

Thanks guys - all duly noted.

The car had a brand new engine fitted about 4000 miles ago, so maybe I'll change the oil soon.

Cheers.
Xan