C240 2001 visiting the dealership (around 51,000 miles) - Benzworld.org

abnegated · 03-03-2008, 12:10 PM

Got several problems appearing at once, will be taking it to the dealership, but wanted to get your opinion on what might be the cause:

1. a knocking noise - the engine sounds like its it a diesel engine (seems stronger from the left front side). Though you really have to pay attention to notice it.
2. cracking/squeezing noise from the front suspension when I drive for a while on a really uneven road but does not go away on normal roads unless you give it a rest for couple of hours. The noise is stronger when you are making turns.

3. steering wheel/power steering: there is a certain "empty space" on the steering wheel; that is you can turn the steering wheel for about 5 degrees on both direction but the wheels do not move.

4. The engine has vibrations that go stronger when in traffic jam, the longer I stay in traffic jams, especially when it's on "drive" and I holding the car with the breaks, the more you can feel it. If you listen to the engine's noise, you can feel that it is not running properly, as if its limping.

Could any of these be caused by engine oil (its grade is 15W50 instead of the recommended 10W40), MAF? Any opion would be appreciated.

V

'91 300CE · 03-04-2008, 08:31 AM

Your oil should not be 15w50... and it should not even be 10w40 recommended... wow... this car takes Mobil 1 full synthetic oil... 0w40 or 0w30 I believe.

That oil that is in there is way too thick to be run through the engine... there may have been permanent damage done if this has been done over a period of time.

I would say that this is contributing to a lot of your engine issues. knocking and the rough idle in drive... as its trying hard to move that oil through with very little engine power.

abnegated · 03-04-2008, 02:14 PM

I realized the issue with the oil. I have only driven it for less than 500 miles. I only noticed it after a friend of mine had actually changed the oil of my car. He borrowed it for a trip he had to make.... makes me wonder why he had done that. Dealership recommended Fuchs 10W-40 which is on the MB recommendation list. I really dont know about it much, but one thing's for sure: dont ever anyone else drive you car!

Thanks,
V

redwood · 03-04-2008, 05:45 PM

The correct oil is Mobil1 0W40 as specified by factory. Another highly recommended lube is ELF 5W40 full syn. I dont think these M112 engines do well with a heavy oil? the tolerances in the engine are much tighter than merc engines of the past. 2.6 litre engine is very durable and should last hundreds of thousands of miles.

'91 300CE · 03-05-2008, 08:13 AM

You need to find a new dealership if they are recommending an oil outside of manufactures specs...

Here is the Fuchs oil with the 229.3 approval: Fuchs Silkolene Pro S 10W-50 - 100% Synthetic Oil For All Race Engines.

Here is what my indy puts in my car at each A and B Service: Mobil 1 SuperSyn European Car Formula 0W-40

This is why I NEVER let friends borrow my cars... he was probably doing you a favor by changing the oil... but sometimes favors turn out to cost a lot in the long run.

Here's something to help:

Mercedes-Benz Engine Oil Recommendations

abnegated · 03-05-2008, 12:13 PM

Thanks guys. Will be visiting them tomorrow early morning. will let you know how it goes.

V

ptalany · 03-05-2008, 03:53 PM

All your symptoms sounded like it's cause by a broken --> engine mount.

I would check for that first b4 taken her in to the dealer. Just my thought, but I might be wrong.

benztech123 · 03-05-2008, 07:23 PM

1. could be a number of things, but dry rockers due to the thick oil may be possible
2. sway bar bushings, upper strut bearings, etc.
3. rack free play, failed tie rod ends
4. motor mounts, misfires, etc.

**Buellwinkle** · 03-06-2008, 04:45 PM

1. Sounds like a vacuum leak. Could be MAF, just unplug MAF and if car runs better, it was the MAF, if it's the same, it's not the MAF.

2. Sounds like warn ball joints, tie rods or control arm bushings

3. See answer to 2.

4. Could be same as answer to 1 or motor mounts.

As for the oil, probably doesn't matter as long as it's a high quality synthetic. It doesn't say where you live in your profile (please update this) but if you live in a very warm climate near the equator, the dealer maybe compensating for the climate with slightly thicker oil. So don't go by U.S. specs if you don't live in the U.S.

FrankW · 03-06-2008, 07:30 PM

synthetic oil as long as they are in the range of the tolerance should all be fine. MB doesn't recommend Liqui Moly 0w40, but I use it anyway it's what' most European tuner uses.

see answers to problems from Buell's or benztech's replies.