Valve Cover Gasket Leak Causing Rough Idle - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
#1 (permalink) Old 02-18-2011, 02:59 PM
BenzWorld Member
 
ewick12's Avatar
 
Date registered: Jan 2008
Vehicle: 1998 ML320
Location: Detroit/New Orleans
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Question Valve Cover Gasket Leak Causing Rough Idle

I took my car in today for noises under the engine, including occasional shuddering. The noise is increased when I put all four windows down at the same time. The car also runs rough when idling and driving under 5 MPH. I took it to a regular car place, not a German-specific place. They used a Snap-on computer to read codes and found the following codes,

054 - Transmission overload protocol confirm not received
065 - Control module N14/3
120 - R/F vehicle speed sensor from ECM implausible, CAN
135 - CAN communication disturbed - engine management
137 - Transfer case control CAN communication implausible
147 - Gear imp. or transmission slipping
150 - Transmission overload protocol confirm not received

The tech wrote down the following notes,

Quote:
valve cover gaskets leaking oil on plugs and plug wire connectors

ignition coil #1 cylinder breaking down

Replace: valve cover gaskets, plugs, wires, 1 ignition coil (or 6 ignition coils)
They quoted me $1,600 based on their ridiculous prices for parts. They wanted to charge $400 for an ignition coil. Their labor only price is $641.25 for R&R of valve cover gasket, spark plugs, and ignition coil. They told me I could bring in my own parts if I want but that they would only provide a warranty for the labor (for 90 days).

I'm thinking about replacing the ignition coil to see if that fixes the issue. They said the valve cover gaskets are leaking onto the spark plugs and wires. I couldn't find a good DIY on the valve cover gasket replacement so I'm slightly hesitant to do that work on my own. I'm not too thrilled about spending $700 on the car. What should I do? Also, any easy fix for the transmission/transfer case codes? I don't notice much with those issues although it shifts hard. I'm hesitant to buy a new ignition coil since the check engine light isn't on.

Hopefully some of y'all can help before I waste any money.

Last edited by ewick12; 02-18-2011 at 03:37 PM.
ewick12 is offline  
Sponsored Links
Advertisement
 
#2 (permalink) Old 02-18-2011, 03:47 PM
pcy
BenzWorld Elite
 
Date registered: Feb 2005
Vehicle: '07 C280 4matic, '06 530i, '98 ML320
Location: MA
Posts: 1,562
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Replacing the valve cover gaskets is not difficult. Just takes 3 to 4 hours of your time. There are no obstructions on the passenger side after you remove the air intake pipe. For drivers side, you may have to disconnect the fuel connection to the rail (after releasing the fuel pressure via the fuel pressure relief valve at the end of the rail). when you have the valve covers open, pulling the plug wires are easy to remove and easy to replace spark plugs as well.

While you have the valve covers open, you can clean the breathing chambers.

The following are some pictures taken during the valve cover gasket replacement on my 98 ML 320.
Attached Thumbnails
Click image for larger version

Name:	DSC00732_resized.jpg
Views:	2166
Size:	83.7 KB
ID:	357932   Click image for larger version

Name:	DSC00743_resized.jpg
Views:	3656
Size:	85.6 KB
ID:	357933  

Last edited by pcy; 02-18-2011 at 03:54 PM.
pcy is offline  
#3 (permalink) Old 02-18-2011, 04:14 PM
BenzWorld Member
 
ewick12's Avatar
 
Date registered: Jan 2008
Vehicle: 1998 ML320
Location: Detroit/New Orleans
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Thanks for the pictures and instructions. I'm wondering if the gasket is even a problem. Shouldn't I be able to smell burning oil if the gasket is leaking? I don't smell anything abnormal under the hood. What caused you to replace your gasket?

In replacing the gasket, do I just place it where the old one was or do I need anything else to seal it? I thought I read something about silicone gel.
ewick12 is offline  
#4 (permalink) Old 02-18-2011, 04:43 PM
BenzWorld Senior Member
 
Date registered: Sep 2009
Vehicle: 2000 Mercedes ML55 AMG
Location: Canada
Posts: 420
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
your rough idle is due to that bad coilpack. replace it and unless your leaking a ton of oil from the gaskets, its not thatttt crucial to replace them
Brettriehl101 is offline  
#5 (permalink) Old 02-18-2011, 05:13 PM
BenzWorld Member
 
ewick12's Avatar
 
Date registered: Jan 2008
Vehicle: 1998 ML320
Location: Detroit/New Orleans
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Quote:
Originally Posted by Brettriehl101 View Post
your rough idle is due to that bad coilpack. replace it and unless your leaking a ton of oil from the gaskets, its not thatttt crucial to replace them
That's exactly what I want to hear. It'd be a lot easier for me to wait 'til May to replace the gaskets.
ewick12 is offline  
#6 (permalink) Old 02-18-2011, 05:50 PM
pcy
BenzWorld Elite
 
Date registered: Feb 2005
Vehicle: '07 C280 4matic, '06 530i, '98 ML320
Location: MA
Posts: 1,562
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by ewick12 View Post
...
What caused you to replace your gasket?

In replacing the gasket, do I just place it where the old one was or do I need anything else to seal it? I thought I read something about silicone gel.
I replaced the valve cover gaskets because oil was leaking, slow leak. That oil leak wasn't causing any problems other than messy looking engine.

There are 2 gaskets (one for left side valve cover and one for the right side valve cover). Each gasket is around $15 on-line. No other sealant is necessary; except, the sealant is necessary if you are going to clean the breathing chambers.

As Brett said above, unless the oil is leaking heavily, it is not that urgent to replace the valve cover gaskets. You can do this during summer. For now, just replace the parts that are necessary for engine to run properly (like ignition coilpacks or wires).
pcy is offline  
#7 (permalink) Old 02-18-2011, 06:14 PM
BenzWorld Member
 
ewick12's Avatar
 
Date registered: Jan 2008
Vehicle: 1998 ML320
Location: Detroit/New Orleans
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Quote:
Originally Posted by pcy View Post
the sealant is necessary if you are going to clean the breathing chambers.
I searched other threads and I am still confused as to how the sealant is used. Witek M said, "Sealant is used to reseal upper breather chambers/oil separators" but I'm not quite sure where I would place the sealant. Here are some pictures of the breathing chambers.
ewick12 is offline  
#8 (permalink) Old 02-18-2011, 06:23 PM
pcy
BenzWorld Elite
 
Date registered: Feb 2005
Vehicle: '07 C280 4matic, '06 530i, '98 ML320
Location: MA
Posts: 1,562
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
You have to apply the sealant around the perimeter of those chambers. If you look closely at the perimeter of the chamber, you will see a 'channel' all around the perimeter of those chambers. You will need to apply the sealant in that channel.
pcy is offline  
#9 (permalink) Old 02-18-2011, 06:52 PM
BenzWorld Member
 
ewick12's Avatar
 
Date registered: Jan 2008
Vehicle: 1998 ML320
Location: Detroit/New Orleans
Posts: 155
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Quote:
Originally Posted by pcy View Post
You have to apply the sealant around the perimeter of those chambers. If you look closely at the perimeter of the chamber, you will see a 'channel' all around the perimeter of those chambers. You will need to apply the sealant in that channel.
Thank you pcy!
ewick12 is offline  
#10 (permalink) Old 02-19-2011, 12:36 PM
BenzWorld Elite
 
Darkmann's Avatar
 
Date registered: Aug 2002
Vehicle: 05 500
Posts: 5,869
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I don't believe that a leak at the valve cover gasket would lead to messing up your plugs/plug pack - the coil packs are above that gasket, I think. I think they saw a leak on the upper chamber (a very common thing with these vehicles) of the valve cover and assumed it was the VC. That upper chamber leak is a $200-$250 fix at your local dealer. Your rough idle is most likely due to the harness and not the leak. Open the hood, take the motor cover off (just pull upwards and it'll come off) look for the oil trail that go onto the coil packs - usually passenger side, in my experience. I think you'll find that the leak is from the uppper chamber to the coil packs. Let us know.

1996 Z32 TT
A 18Hp lawn mower
370Z - I want one!
Darkmann is offline  
Reply

  Mercedes-Benz Forum > Mercedes-Benz Vans/Trucks/SUV/Others > W163 M-Class


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Topic Author Forum Replies Last Post
Valve Cover Gasket Leak, Replacement JonzBenz W202 C-Class 8 02-02-2012 07:13 PM
Valve cover gasket leak, your opinion? Rat2 W210 E-Class 6 07-12-2010 10:30 PM
Valve cover gasket leak.... Vivanashvegas W140 S-Class 9 05-20-2010 11:13 AM
Recurring Valve Cover Gasket leak dichronic R/C107 SL/SLC Class 4 04-20-2010 06:56 PM
Oil leak at the valve cover gasket? Chris-CA Bay R170 SLK Class 5 07-02-2002 04:13 PM

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome