Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 07-03-2003, 11:17 PM
Registered User
 
Join Date: Feb 2001
Location: Catron County, NM
Posts: 27
E300D Oil Pressure Drops to -0-

My car is a 95 E300 diesel with 102K miles. I regularly change my own oil and filter and use a brand name 15W-40.

I just recently noticed that when I let up on the accelerator pedal the oil pressure gauge (factory installed in the instrument cluster)drops to zero or at least indicates a drop to almost nothing.

I have monitored oil levels in the last few days since I noticed this and I am not low or anything on oil. As I say, I just noticed this recently and, as I recall, the gauge used to read at least some level of pressure even at idle with the pressure rising some as the engine developed power under acceleration or pull.

Any ideas here? What does this sound like? I would guess a bad oil pressure sender. Does this vehicle have such? I am guessing this per my experience with my Dodge Cummins pickup.

Again, any words of wisdom are appreciated.

Reply With Quote
  #2  
Old 07-03-2003, 11:19 PM
turbodiesel
Guest
 
Posts: n/a
I think the oil pressure sensor is actually a physical line that runs behind the dash into the cluster - but they may have changed this for the newer models.

Obviously the first thing I would check is that the dash gauge is working.. if it is actually at 0 bar then I would say it's time for a new oil pump. Don't drive the car until you get this figured out.
Reply With Quote
  #3  
Old 07-04-2003, 04:10 PM
Registered User
 
Join Date: Feb 2001
Location: Catron County, NM
Posts: 27
Actually I noticed this whole problem with the gauge dropping to zero under little or no engine load on a drive up to Denver and back earlier this week. The E300D ran fine up and back so I guess I didn't blow the engine or anything.

What is a good way to troubleshoot the oil pump?

Any other ideas?
Reply With Quote
  #4  
Old 07-05-2003, 01:43 AM
ATLD's Avatar
Registered User
 
Join Date: Oct 2001
Location: PA
Posts: 272
I'd think that there would be a warning light and/or alarm that would indicate no oil pressure if it would drop to null (or a lack of engine oi in the sump too), but can't verify this because I don't have a 95'. My older Bimmer (electronics from here to hell and back) has both a gauge and pressure warning light so I don't see why the MB wouldn't too.

I'd have the gauge replaced/tested before you pull the pump. If it's an oil line that runs to the gauge in the dash, could it be clogged? Does the oil pressure run at its precise normal pressure while driving or lower too?

Sincerly,

ATLD
Reply With Quote
  #5  
Old 07-05-2003, 10:12 AM
Registered User
 
Join Date: Jan 2000
Location: PA
Posts: 5,440
R Walter,

With hot oil, what does the gage read at 1000, 1500, 2000 and 2500 RPM?

P E H
Reply With Quote
  #6  
Old 07-05-2003, 10:45 AM
Registered Diesel Burner
 
Join Date: Aug 2001
Location: Northern Virginia
Posts: 2,911
I think your car probably has an oil sending unit on the back of
the oil filter housing, and a wire to an electronic gauge. At least my 1987 W124 has this, so yours probably does too.

You do need to work on this problem fairly quickly, because if the oil pressure reading is accurate, you have an oil pressure problem that needs to be fixed to avoid engine damage.

However, it is a little more likely that you have a sender that is going bad. You should be able to select one on FastLane and install it as a test for about $60, if you want to risk that amount as a "blind" part substitution effort. Besides, you would spend that much if you just walk into a Mercedes dealership and say "Hello" to the service manager.

Give us some more information on your symptoms. In addition to what PEH asks:

What is your oil pressure reading when cold at idle?

What is your oil pressure reading when hot at idle?

What is your oil pressure reading when hot at 50 mph or so?

I had a sending unit bad on my 1987 300D when I got it, but with a different indication than yours. In my case, the oil pressure gauge would peg immediately when the key was turned to ON, even with the engine not running. This was a clear indication of gauge malfunction. Your issue is not so clear cut.

But you need to do something right away.

Ken300D
__________________
--------------------------
1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles
Reply With Quote
  #7  
Old 07-05-2003, 01:09 PM
Registered User
 
Join Date: Apr 2003
Location: SoCal
Posts: 140
Owners Manual

According to the book:

Pressure may drop at idle speed to 4.4 psi (0.3 bar) at operating temp. This will not jeoprdize its operational reliability. Pressure must rise at immediately upon acceleration.

If the noil pressure gauge needle drops to "0" then damage to the engine may occur. Shut down and call the dealer. Do not operate the car until the condition id repaired.

When I bought mine, a 95, there were three 95's on the lot, all black, all with 70,000 on them. Two of the three had no pressure at idle, but came up as soon as you stepped on it. I bought the one that had pressure, and because ot also had a gray interior. The others were black/black. Hope this helps

B52 rule
__________________
1960 190D (college car), gone
1995 E300D, 300 k
2004 Infiniti G35 (spouse mobile)
2003 Nissan Frontier Crew Cab
2007 Jeep Grand Cherokee Overland 3.0L MB diesel, 170K
1978 GMC Classic Motor Home
Reply With Quote
  #8  
Old 07-06-2003, 11:14 PM
Registered User
 
Join Date: Feb 2001
Location: Catron County, NM
Posts: 27
Thanks for the advice. I've not run the MB over this long weekend and am going to get it in to my MB shop in the morning to have them check the oil pressure.

Hope its only the sender although from my MB service CDRom it seem that changing out the oil pump is not THAT complicated a deal. Am I right about this? Can the oil pump be changed out by the average handy mechanically inclined owner?

Thanks......
Reply With Quote
  #9  
Old 07-07-2003, 02:48 AM
Registered User
 
Join Date: Jan 2001
Location: oregon
Posts: 2,013
If you diy make sure that you fill the pump with oil before you bolt it back up as at least mine did not self prime, It's not super difficult just a bit tricky as you have to deal oil chain guide oil chain and keeping oil in pump ,I did it on my gasser but should be similer on diesel .........
William Rogers.....
Reply With Quote
  #10  
Old 07-07-2003, 01:45 PM
Registered User
 
Join Date: Feb 2001
Location: Catron County, NM
Posts: 27
Well, I dropped off the E300D this am at my MB guy's shop. This guy has always been straighforward with me and I trust him, pretty much.

First thing he asked was what kind of oil have I been running. I told him that for the last 5500 miles I'd been using Pennzoil 15W-40 and before that I'd usually run Castrol 15W-40. He said "ah hah!" That he didn't like Pennzoil and that in this climate (Alb, NM) he was putting 20W-50 in his customers' diesels. That 15W-40 didn't stand up to this heat as well as 20W-50, etc.

Anyway, he's going to check the oil pressure and (hopefully) rule out things like a bad oil pump!
Reply With Quote
  #11  
Old 07-07-2003, 05:39 PM
mechmagcn's Avatar
Just another diesel junky
 
Join Date: Aug 2002
Location: Mt Holly AR
Posts: 290
Not trying to start another oil war, but....

Are Penzoil or Castrol either one rated for use in a diesel engine?
__________________
1971 R600 Mack toterhome (SuperDawg)
99 NU-WA Snowbird 34+2 SE 102 5er
If it's not diesel, it's not in my stable!
53 F100 617.951/auto
95 Dodge 3500 Cummins/5 speed service truck
Reply With Quote
  #12  
Old 07-07-2003, 11:49 PM
gsxr's Avatar
Unbanned...?
 
Join Date: Aug 2001
Location: USA
Posts: 8,033
Actually on the oil, you are right, he is WRONG. There is no non-synthetic 20W-50 on the market that is diesel rated, AFAIK. The viscosity is not as important as having a diesel-rated (CG, CH, CI) oil in the crankcase! 15W-40 is the viscosity for almost all top diesel oils. The two best dino oils are Delvac-1300 and Delo-400. I would use either of these and NOT any Penzoil or Castrol product (for reasons I won't go into, to avoid the aforementioned oil wars). Personally I use synthetics, either Delvac-1 5W-40 or Mobil-1 15W-50. But *please* don't use any 20W-50 unless it's one of the RedLine or Amsoil synthetics, which are about the only commonly available 20W-50 oils that I know of which are diesel rated! Non-diesel rated oil is NOT designed to suspend the soot load that these engines create. Oh, and you might want to edumacate your "mechanic" as well...**sigh**
__________________
Dave M.
Boise, ID

1997 E420 - 155kmi (Bugeyes)
1994 E420 - 145kmi (Blondie)
1993 500E - 193kmi (Lollipop)
1992 400E - 189kmi (Stinky Dirty)
Check out my website photos, documents, and movies!
Reply With Quote
  #13  
Old 07-08-2003, 05:34 PM
Registered User
 
Join Date: Feb 2001
Location: Catron County, NM
Posts: 27
Well, things turned out okay for me and my E300D.

The problem was the sender. My MB guy did an oil pressure test and the pressure was up to spec at idle, 1000rpm, 2000rpm, 2500rpm and so on. He checked the voltage from the sender and it was very irregular. He popped a new one in ($60 plus 1 hr labor for everything) and the gauge is reading back to normal now.

Whew! I was a little worried that I might have a more serious problem, but deep down I felt that it was the sender because of all the uneventful driving I'd done since I first noticed the problem occurring on a road trip to Denver.

This MB guy of mine keeps trying to suggest 20W-50, but, as some prior posters have commented, 20W-50 typically is not diesel rated. I guess I've missed the so-called "oil wars", but what do others run in their diesels, specifically the 606 engine?
Reply With Quote
  #14  
Old 07-08-2003, 05:49 PM
gsxr's Avatar
Unbanned...?
 
Join Date: Aug 2001
Location: USA
Posts: 8,033
For dino oil, the BEST stuff on the market is Delvac-1300 and Delo-400. For synthetic, use Mobil, Amsoil, or RedLine diesel-rated products in xW-40 or xW-50 weights (not any xW-30 or thinner). There are some other exotic synthetics that are also great, but not commonly available. The Mobil stuff is excellent and easy to buy nationwide.

For officially approved oils, there are Mercedes spec sheets (numbered "228.5", etc) that list officially approved oils. Mobil-1 15W-50 is on the diesel approved sheet and is what I recommend for most applications, plus you can extend drain intervals to 7.5-10kmi to help offset the extra cost...
__________________
Dave M.
Boise, ID

1997 E420 - 155kmi (Bugeyes)
1994 E420 - 145kmi (Blondie)
1993 500E - 193kmi (Lollipop)
1992 400E - 189kmi (Stinky Dirty)
Check out my website photos, documents, and movies!
Reply With Quote
  #15  
Old 07-08-2003, 10:14 PM
Registered User
 
Join Date: Feb 2001
Location: Catron County, NM
Posts: 27
gsxr,

I use a ton of the Chevron Delo-400 (15W-40) in my 12 valve Dodge Cummins Turbo diesel. Every 3000 miles it gets a fresh 11 quarts. Delo 400 is the only oil I've used in this truck.

I had been using Castrol 15W-40 in my MB E300 Diesel until I only recently switched to Pennzoil 15W-40, mainly because its much easier to find (WalMart). You don't seem too fond of Castrol. Why??

Deep down I kinda feel that there's not a lot of difference between brands assuming you're staying with the same weights and SAE/API classifications for comparison purposes. But, then, I am pretty brand loyal when push comes to shove.

I did check some 20W-50 I had out in the garage. (Castrol for my son's 88 BMW 325i) and some 10W-30 (Quaker State) and some straight 30 weight (Pennzoil). The API classificaion was SL only. No CJ, CH, CG, et al which is what the diesel engines usually call for. Obviously this (Castrol 20W-50) would not meet the spec for my E300D. Don't know why my independent MB garage guy was so sure to use 20W-50 in my vehicle. (He seems to be a sharp enough fellow.)

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 10:25 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page