95 E320: Rough idle above 4000RPM - Page 2 - PeachParts Mercedes-Benz Forum

fastpakr · #16 08-10-2006, 09:18 AM

OK, I'll try asking this for a fourth time. Do you have ANY IDEA what the factory oil recommendation was for your engine?

softconsult · #17 08-10-2006, 09:49 AM

I will answer this recommended oil question. Take your pick. The owner's manual for that engine specificies everything from 5-30 to 5-50. Also included are 10-30, 20-50, 15-50 and finally 10-40. It all depends on the ambient temperature range expected.

It's not the oil. I would think in terms of what else has changed. I would focus on the oil filter. Is the filter a Mann or Hengste (sp?). Or is it a McParts made in India? Also is the rubber o-ring properly seated?

I would put on a new quality filter and see what the result is.

Steve

fastpakr · #18 08-10-2006, 09:57 AM

Quote:

Originally Posted by softconsult

I will answer this recommended oil question. Take your pick. The owner's manual for that engine specificies everything from 5-30 to 5-50. Also included are 10-30, 20-50, 15-50 and finally 10-40. It all depends on the ambient temperature range expected.

It's not the oil. I would think in terms of what else has changed. I would focus on the oil filter. Is the filter a Mann or Hengste (sp?). Or is it a McParts made in India? Also is the rubber o-ring properly seated?

I would put on a new quality filter and see what the result is.

Steve

Thanks for the heads up. I agree - the problem is elsewhere.

EricSilver · #19 08-10-2006, 11:37 AM

The car's manual says "See Dealer" regarding which oil to use. Dealers (and service shops), in turn, use the range of oils Softconsult specified, depending on their preference and experience.

The filter I installed yesterday is the same Bosch available in Fastlane. The old rubber O-Ring was replaced with a new one, which was reseated properly. There was also a metal washer with the new filter. Did not know where it went, and set it aside. Did not see a similar one after removing the old filter.

The filter appears to be the most likely cause, since the readings are now normal for this engine. I doubt the 20-50 has much to do with it since it will not flow that much differently than 15-40 once the engine reaches operating temperatures. I will know for sure tomorrow, when the sender and the gauge are checked.

The only real "problem" is what I am accustomed to seeing when I look at the oil gauge. This is a different car, different engine and I will simply need to adapt to its different behavior.

EricSilver · #20 08-11-2006, 10:36 AM

All is fine. It was the filter. Have 15W40 in now, and pressure at 90C+ is 1.2to 1.3 in gear, and 1.8 to 2.0 in neutral.

Quote:

Originally Posted by fastpakr

20w50 sounds ridiculously high. I'd have expected something more like 5w30 winter, and 10w30 summer.

Correct, it was ridiculously high, to the point where all day yesterday I could feel a low, rumbling vibration at idle while the oil needle wiggled. I don't see, or feel, either of those anymore.

Had I used 15-40 on Wednesday, I would have been spared the time and expense of a second oil change today. Some happy news, however, is that the oil change, fluid top-off, basic inspection, etc. cost only $39 at this MB-only shop, so it is no longer practical, or economically sensible, for me to do my own oil changes. (Not that I will miss that.)

fastpakr · #21 08-11-2006, 10:39 AM

Glad to hear you got it sorted out.

dtf · #22 08-11-2006, 11:04 AM

How much oil are you putting in? The 8 quarts specified in the manual has been superceded I believe by a TSB that says put no more than 7 quarts in. The 8 quarts gets whipped up because it is too much oil in pan.

Arthur Dalton · #23 08-11-2006, 11:17 AM

Quote:

Originally Posted by dtf

How much oil are you putting in? The 8 quarts specified in the manual has been superceded I believe by a TSB that says put no more than 7 quarts in. The 8 quarts gets whipped up because it is too much oil in pan.

Correct
TSB # 00-134.18/45
7 L is new reduced capacity.
Many of us do believe the new level was influenced by notorious head gasket oil leaks. but no one is saying so.

EricSilver · #24 08-11-2006, 11:19 AM

Quote:

Originally Posted by dtf

How much oil are you putting in? The 8 quarts specified in the manual has been superceded I believe by a TSB that says put no more than 7 quarts in. The 8 quarts gets whipped up because it is too much oil in pan.

When I did the 20W50 change on Wednesday, I did exactly 7 qts. I used an extractor through the dipstick tube, so figure perhaps 1/4 to 1/2 quart left in the pan.

EricSilver · #25 08-11-2006, 11:20 AM

Also -- I am sure that today's change, by the techs, was at 7 qts also.

EricSilver · #26 08-15-2006, 12:57 PM

Quote:

Originally Posted by Arthur Dalton

Correct
7 L is new reduced capacity.
Many of us do believe the new level was influenced by notorious head gasket oil leaks. but no one is saying so.

If I decide to use 20W50 again, should that be further reduced to, say, 6 qts/litrs?

fastpakr · #27 08-15-2006, 01:16 PM

There's no reason the capacity should be altered by changing weight. I'll argue again for sticking with the lightest oil that satisfies original requirements and oil pressure specifications. Anything beyond that is just reducing oil flow to the harder to reach areas and increasing pumping losses.

Arthur Dalton · #28 08-15-2006, 01:44 PM

Quote:

Originally Posted by EricSilver

If I decide to use 20W50 again, should that be further reduced to, say, 6 qts/litrs?

No .. Same measure. Benz TSB states that you are looking for the 1/2 way mark on the dip-stick measure when engine coolant is at operating temp.
That is the new measure and there is a change in the manual referring to such after the change.

EricSilver · #29 08-16-2006, 11:09 AM

In an earlier post, I mentioned that the oil pressure needle would peg just at, but not on, the 3 bar line. It now pegs above the line, and the idle, in gear, with a hot engine, ranges from.7 to 1.1.

In the last couple of days, I noticed an occasional click or pop from the speaker area. This occurs when the radio is on and off. At first I thought it was radio static, or a speaker wire issue, but realized that was not likely if the radio was turned off.

Today, after the click/pop, I noticed the oil pressure needle was pegged well above the 3-bar line, so I am beginning to suspect that a loose or improper connection in or behind the cluster is causing my oil pressure needle freakiness. (I could be mistaken, but I am sure I also saw the fuel needle momentarily jump back and forth a few days ago.)

Is there a relay, switch or electrical connection in the relay box, or in the instrument cluster, that would affect the oil pressure (and other) instrument gauges?

EricSilver · #30 08-16-2006, 11:15 AM

Quote:

Originally Posted by fastpakr

I'll argue again for sticking with the lightest oil that satisfies original requirements and oil pressure specifications. Anything beyond that is just reducing oil flow to the harder to reach areas and increasing pumping losses.

I agree, and will stick with the 15W40, which flows like water. When reflecting on my other, non-car mechanical lubication experiences, heavier oils seem to leave behind as much -- or more -- dirt and contaminants as they remove, and I would think the same would be true in a car's engine.