M119.975 oil tubes - engine no 008xxx, car from 7.1993

[truls221]

Dear all,

I am a proud new owner of a '93 400 E and enjoy the car really much.

However since I bought the car and drove about 1000 km the oil pressure started to drop.

Since I need the car in working condition and need it to be reliable I ordered new plastic oil tubes, oil pressure sensor and spring relief valve without hesitating.

However, today when I changed the thermostat, I forgot that I could see the oil tube from the filler cap (at least one of them) and noticed that I have the metal tubes.
From what I read I was sure that my car should have plastic ones, and that was the problem causing the lowered pressure.

The gauge stays at 3 during warmup, but is around 2.25 when the engine is warm.

Would please need some advice on how to proceed. Should I dissasemble the valve covers and clean my existing tubes, and replace the seals with those from the plastic ones, or should I change them to the plastic ones completely, or should I simply don't open the valve covers at all, and chance that the sensor is default?

I am aware of that I can return the plastic ones to the dealer and just buy the orings, but I cant wait for the new order.

I have seem that in most cases the oil tubes are the problem, if not could it be just the seals? Or is this not an issue?
Should I change the pressure relief valve inside the filter housing at the same time, or just leave it with the sensor when I am at it?

the problem is that I will drive the car for 700 km during the weekend, and have only tomorrow to fix the problem.

thanks for any help

best regards

Truls

 

[Glen]

Welcome to the board!
Your oil pressure is fine as is. A fully warmed engine can have oil pressure down as low as .5 bar at idle. As long as you see a full 3.0 bar by 1800 RPM you have nothing to worry about.

 

[gsxr]

Note: If the oil pressure is showing below 3 bar with the engine above ~1500rpm and fully warmed up, the oil pressure sending unit may be faulty. Before chasing a possible "low pressure" problem, I would replace the sensor. I've had to change the sensor on almost all of my cars due to either leaking, or incorrect readings.

The metal oil tubes were phased in during late '92 and early '93 model year production... some late 92's have plastic tubes and some early 93's have metal, but by late 93 I think all were switched to plastic. Sounds like yours was one of the last to still receive the metal tubes - nice bonus.

Oh, and welcome aboard!

 

[truls221]

Note: If the oil pressure is showing below 3 bar with the engine above ~1500rpm and fully warmed up, the oil pressure sending unit may be faulty. Before chasing a possible "low pressure" problem, I would replace the sensor. I've had to change the sensor on almost all of my cars due to either leaking, or incorrect readings.

The metal oil tubes were phased in during late '92 and early '93 model year production... some late 92's have plastic tubes and some early 93's have metal, but by late 93 I think all were switched to plastic. Sounds like yours was one of the last to still receive the metal tubes - nice bonus.

Oh, and welcome aboard!

Thanks for the answer. I will replace the sensor at first, since its quick.

best regards

Truls

 

[J-Sauce]

Dave, do you mean to say if the engine is BELOW ~1500rpms and still showing full pressure?

 

[gsxr]

Nope... if it reads below 3 bar with the engine revved up, that's an abnormally low reading. The gauge should peg at 3 bar when revved up (usually by 1500-1800rpm or so). If it's reading too low, I'd suspect the sender or the gauge first. It would be unusual for an M119 to actually have low oil pressure - difficult to confirm without attaching a mechanical gauge.

On my W124's, I've encountered probably 5 or 6 faulty senders, and only one faulty gauge (wouldn't indicate above ~2 bar). All W124's use the same sender & gauge regardless of engine (4/5/6/8 cyl, gas or diesel).

 

[truls221]

Thanks for the help! Oil pressure is now showing correct, after changing the sensor. It shows 1.5 at idle and 3 at load.

The 16 oil tubes will come handy some other time supposedly.

 

[J-Sauce]

Gah! My dyslexia must have been kicking in...but only half way. I read your sentence as "showing ABOVE 3 bar with the engine above ~1500rpm". That's what I get for reading on my phone.

Good to know they are all the same for every w124. I can start snagging them all at the junkyards. They are a bit spendy to buy new (~$65). The 500E got one recently, but I don't mind grabbing a used one for the wagon.

 

[mb280sel1985]

Is it possible to find out if engine uses plastic tubes or metal tubes by looking at the vin#?

 

[gerryvz]

Not entirely, but in a general sense, yes. There are some documented situations where motors with plastic tubes came before motors that had metal tubes installed.

 

[gsxr]

Is it possible to find out if engine uses plastic tubes or metal tubes by looking at the vin#?

It's much easier to look through the oil fill hole. If you're considering a car to purchase and want to find out, there's no guarantee from the VIN or engine number.

Even the infamous Bernard-built 1992 AMG 6.0L engine had the metal oil tubes removed and replaced with plastic ones!!! It's all in the photos. No idea why he did that...

:?:

 

[400Eric]

7/93 is really kinda late to still have metal oil tubes when EVERY post-3/93 M119 that I have seen has plastic ones. I would submit that it is possible that they were already replaced with metal ones sometime in the car's past. Either way, that is definitely a stroke of good luck!
Regards, Eric