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 ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 11-19-2003, 05:33 PM
chazola's Avatar
Registered User
 
Join Date: Nov 2003
Location: Dorset, United Kingdom
Posts: 1,238
Bonkers Oil Pressure Gauge- W124

The oil pressure gauge on my W124 has started acting up when the engine is warm (after 1/2hr- 1 hour or so). At idle, in drive or in R, 3 or 2, the pressure bounces around 1. Doesn't drop below 1 though. B4 today it was always around 2. If i shift into N or P it goes back up to 2. the RPM also drops to around 500 when the pressure is at 1, then back up to around 7-800 in N or P.

At normal driving the meter is pegged back on 3.

oddly, it started this just after i'd just filled up with gas. I was getting the surging idle a couple of days ago, again when the engine was warm, which seem to stop today.

Last oil change was @ 2000 miles ago, at dealership.
I have pulled the R16 resistor trick yesterday, gonna put it back it when it stops raining.

91 300E 192k with leaky front cover.

any thoughts?
Reply With Quote
  #2  
Old 11-19-2003, 05:45 PM
G-Benz's Avatar
Razorback Soccer Dad
 
Join Date: Apr 2001
Location: Dallas/Fort-Worth
Posts: 5,711
I'm not sure how long you've owned your car or when you started paying attention to the oil pressure gauge, but what you've just described the oil pressure gauge functioning properly.

The surging idle is a different problem altogether, and is usually the result of a vacuum leak. The oil pressure gauge just responds in kind to what the engine is doing. Mine has the surge problem, and the needle bounces along.

Unlike some other makes where the gauge needles just leap to some stasis point and remain there, MB gauges actually "tell" you something.

Here is what you should see (on average).

When car is cold (and oil is cold and thick), pressure gauge should reach "2" or above.

After warming up, it will go down to as low as "1" on idle.

Pressure reads between "2" and "3" during easy cruising and pegs to "3" during acceleration.

If you have a REAL oil pressure problem, your readings would be "1" or lower ALL of the time.

BTW, the measurement is in bar...
__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car
Reply With Quote
  #3  
Old 11-19-2003, 05:52 PM
chazola's Avatar
Registered User
 
Join Date: Nov 2003
Location: Dorset, United Kingdom
Posts: 1,238
thanks for the speedy reply.
I've owned the car for only a few weeks and I pay (almost!) constant attention to my pressure gauge. This is my first Merc though, so it's hard to know what to expect or to relate to, as the manual doesn't give you many pointers.
The reason I posted this thread is that this was the first time i'd noticed it going down to 1, probably because I've done only short trips/highway driving with it up until now. i.e., from what you say it would either be at 2 with the cold oil, or pegged at 3 on the highway.
I believe the numbers correspond to 15 psi or so steps?
Reply With Quote
  #4  
Old 11-19-2003, 06:10 PM
G-Benz's Avatar
Razorback Soccer Dad
 
Join Date: Apr 2001
Location: Dallas/Fort-Worth
Posts: 5,711
According to Google:

1 bar = 14.5037738 pounds per square inch

And watch your temp gauge needle too. It will surprise you as well (especially during the hot summer months)...
__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

Last edited by G-Benz; 11-19-2003 at 06:15 PM.
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 07:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page