Misfire when hot - Mercedes Benz SLK Forum

SLK R170 General Discussion SLK 200, SLK 230K, SLK 320, SLK32 AMG

 1Likes
  • 1 Post By nimbusgb
 
LinkBack Thread Tools
#1 Old 08-11-2013
Premium Member
 
nimbusgb's Avatar
 
Join Date: Jun 2008
Location: North Wales
Vehicle: '14 SLK 55 AMG Silver ( past ) '06 SLK 55 AMG Bright Blue, '03 SLK 320 black, '00 SLK 230 blue.
Other Toys: Oceanis 390 ( Greece)
Posts: 1,604
Country:
Chats: 1
Mentioned: 74 Post(s)
Tagged: 0 Thread(s)
Quoted: 253 Post(s)
Thanks: 49
Thanked 141 Times in 124 Posts
Garage
(Thread Starter)
Misfire when hot

Ok I have a problem/problems that is/are greying my hair even more.

SLK 320

If the car is left to stand idling ( driveway or a traffic jam ) for a long time the temperature gets to 80, stabilises for a while and then kicks over and slowly climbs to around 95.

1-where is the temperature sensor, how can I test it as I'm not sure the fan is kicking in.

2- can the system get airlocked. How can I bleed it?

The car is not loosing cooling fluids!

After a while at 95 degrees trying to move off the car misses badly. This is always on the right hand bank, cylinders 1 and 2 and if its really bad 3. never seen a report of a misfire on left bank. The longer it stands at 95 the worse it gets.

Turning off the ignition for a few seconds usually clears the missfire for a few minutes at least.

Flooring it hard the car pulls ok but ocassionally, very ocassionally at around 5000 to 5500 it's like the ignition was turned off! Engine does not fire at all, flatlines for perhaps one o two seonds then continues as normal.

I have replaced plugs, coils, maf , both O2 sensors and the crank sensor and although the misfire changes personality a little bit the basic circumstances do not change!

3- could this be valve related? Hot= valves on right bank not seating/opening?

4- any and all suggestions about what to try next accepted! I'm at my wits end!

I have a buyer for my car and I need the driveway space for the '55!
nimbusgb is offline  
Sponsored Links
Advertisement
 
#2 Old 08-11-2013
Administrator/Founding Member

 
jbanks15's Avatar
 
Join Date: Jun 2006
Location: Tampa, Florida
Vehicle: 2009 SLK 55 AMG Kleemann Supercharger, ECU tune, Headers and LSD, CF Diffuser
Posts: 91,732
Country:
Chats: 38
Mentioned: 470 Post(s)
Tagged: 5 Thread(s)
Quoted: 6543 Post(s)
Thanks: 3,246
Thanked 11,083 Times in 8,437 Posts
your profile says 55 and now you say SLK 320

you have 2 slks?


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Jeff, US Army Master Sergeant Retired
Administrator/Founding Member
2009 SLK 55 AMG Black/Black
Kleemann Supercharger thread here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Kleemann ECU Tune, headers and downpipes thread here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Albums:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

ClearBra
OEM MB Plexiglass Draught Stop
Smarttop version 3.22
Previous - 02 SLK 320, 05 SLK 350
jbanks15 is online now  
#3 Old 08-12-2013
Premium Member
 
nimbusgb's Avatar
 
Join Date: Jun 2008
Location: North Wales
Vehicle: '14 SLK 55 AMG Silver ( past ) '06 SLK 55 AMG Bright Blue, '03 SLK 320 black, '00 SLK 230 blue.
Other Toys: Oceanis 390 ( Greece)
Posts: 1,604
Country:
Chats: 1
Mentioned: 74 Post(s)
Tagged: 0 Thread(s)
Quoted: 253 Post(s)
Thanks: 49
Thanked 141 Times in 124 Posts
Garage
(Thread Starter)
This week I do! Collect the 55 this coming weekend. Thread here

Have sold the 320 but really want to fix this misfire before I hand it to the new owner!
nimbusgb is offline  
 
#4 Old 08-12-2013
Administrator/Founding Member

 
jbanks15's Avatar
 
Join Date: Jun 2006
Location: Tampa, Florida
Vehicle: 2009 SLK 55 AMG Kleemann Supercharger, ECU tune, Headers and LSD, CF Diffuser
Posts: 91,732
Country:
Chats: 38
Mentioned: 470 Post(s)
Tagged: 5 Thread(s)
Quoted: 6543 Post(s)
Thanks: 3,246
Thanked 11,083 Times in 8,437 Posts
That, my friend, is very commendable!


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Jeff, US Army Master Sergeant Retired
Administrator/Founding Member
2009 SLK 55 AMG Black/Black
Kleemann Supercharger thread here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Kleemann ECU Tune, headers and downpipes thread here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Albums:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

ClearBra
OEM MB Plexiglass Draught Stop
Smarttop version 3.22
Previous - 02 SLK 320, 05 SLK 350
jbanks15 is online now  
The Following User Says Thank You to jbanks15 For This Useful Post:
#5 Old 08-12-2013
Premium Member
 
cobra8272's Avatar
 
Join Date: Jul 2012
Location: Perth, Australia
Vehicle: '05 SLK350
Other Toys: Fender Strat, Fender Tele
Posts: 1,059
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Thanks: 80
Thanked 105 Times in 79 Posts
Garage
Maybe try going through the normal stand and idle procedure and allow it to misfire then turn off the ignition and pull the plugs and check how they look.
I'm thinking injectors or overheating fuel in the return line to the tank, perhaps something to do with the fuel pump or electronic injection system. I'm not 100% on the R170 so its a bit of guess work and desperation .
Hope it may point you to some alternatives.
Cobra


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Smart Top
Daytime LEDs
LED Lighting pack
MB Door lights
cobra8272 is offline  
#6 Old 08-12-2013
Premium Member
 
cobra8272's Avatar
 
Join Date: Jul 2012
Location: Perth, Australia
Vehicle: '05 SLK350
Other Toys: Fender Strat, Fender Tele
Posts: 1,059
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Thanks: 80
Thanked 105 Times in 79 Posts
Garage
Forgot to add -
My R171 runs at 80 whilst moving but goes up to 95 whilst standing in traffic.
Always has and been told its normal.
My misfire was due to a faulty coil pack.


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

Smart Top
Daytime LEDs
LED Lighting pack
MB Door lights
cobra8272 is offline  
The Following User Says Thank You to cobra8272 For This Useful Post:
#7 Old 08-13-2013
Premium Member
 
nimbusgb's Avatar
 
Join Date: Jun 2008
Location: North Wales
Vehicle: '14 SLK 55 AMG Silver ( past ) '06 SLK 55 AMG Bright Blue, '03 SLK 320 black, '00 SLK 230 blue.
Other Toys: Oceanis 390 ( Greece)
Posts: 1,604
Country:
Chats: 1
Mentioned: 74 Post(s)
Tagged: 0 Thread(s)
Quoted: 253 Post(s)
Thanks: 49
Thanked 141 Times in 124 Posts
Garage
(Thread Starter)
Quote:
Originally Posted by jbanks15 View Post
That, my friend, is very commendable!
Too damned honest for my own good some times!
nimbusgb is offline  
#8 Old 08-13-2013
Premium Member
 
nimbusgb's Avatar
 
Join Date: Jun 2008
Location: North Wales
Vehicle: '14 SLK 55 AMG Silver ( past ) '06 SLK 55 AMG Bright Blue, '03 SLK 320 black, '00 SLK 230 blue.
Other Toys: Oceanis 390 ( Greece)
Posts: 1,604
Country:
Chats: 1
Mentioned: 74 Post(s)
Tagged: 0 Thread(s)
Quoted: 253 Post(s)
Thanks: 49
Thanked 141 Times in 124 Posts
Garage
(Thread Starter)
Quote:
Originally Posted by cobra8272 View Post
Forgot to add -
My R171 runs at 80 whilst moving but goes up to 95 whilst standing in traffic.
Always has and been told its normal.
My misfire was due to a faulty coil pack.
Thanks for that.

The more I investigate the more I suspect that my ecu is suffering from a problem I have come across. The coil drivers in the ecu may have a problem.

The fact that the problem goes away, at least for a while seems to point to an electrical problem.

Mob in southampton have quoted Ł333 for repairing the ecu ( if it's broken ) May just have to come to some agreement with the buyer.

Going to try a really coarse test. Have some cooling spray, will get the lot hot with the ecu lying loose and then cool off the ecu, which gets good and toasty!

Maybe just replacing the fan in the electronics box will fix it!
cobra8272 likes this.
nimbusgb is offline  
#9 Old 08-13-2013
Premium Member
 
Join Date: May 2010
Location: Atlanta
Vehicle: 2005 SLK 55; 2005 SLK 350
Other Toys: Several past R170's
Posts: 4,307
Country:
Chats: 0
Mentioned: 594 Post(s)
Tagged: 0 Thread(s)
Quoted: 912 Post(s)
Thanks: 155
Thanked 518 Times in 479 Posts
Just gussing here, I'm totally unfamiliar with your car or engine:

- A ground issue affecting one bank only?
- Some other electrical component that is "one per bank" (my older volvo has two ignition amps, one for 1-3, one for 4-6).

If you're not sure your fan is running it might be good to make a manual check.
efair is offline  
#10 Old 08-13-2013
Premium Member
 
nimbusgb's Avatar
 
Join Date: Jun 2008
Location: North Wales
Vehicle: '14 SLK 55 AMG Silver ( past ) '06 SLK 55 AMG Bright Blue, '03 SLK 320 black, '00 SLK 230 blue.
Other Toys: Oceanis 390 ( Greece)
Posts: 1,604
Country:
Chats: 1
Mentioned: 74 Post(s)
Tagged: 0 Thread(s)
Quoted: 253 Post(s)
Thanks: 49
Thanked 141 Times in 124 Posts
Garage
(Thread Starter)
Quote:
Originally Posted by efair View Post
Just gussing here, I'm totally unfamiliar with your car or engine:

- A ground issue affecting one bank only?
- Some other electrical component that is "one per bank" (my older volvo has two ignition amps, one for 1-3, one for 4-6).

If you're not sure your fan is running it might be good to make a manual check.
The 320 has a coil pack per cylinder and 2 spark plugs per cylinder. not sure that there is only one earth per bank but I'll go have a dig around.

The temperature seems to be standard so it's appears to be just once that heat soaks through to all the components ...... kind of points to the Ecu again.

Ran the car up to 'failure mode' yesterday, got cylinder 1 misfiring. Disconnected the coil from the harness by unclipping the connector, misfire did not change in the least so it looks like that signal was not getting to the coil! Plugging it back on did not clear the misfire.

turn off, turn on and it's gone. but came back shortly.

Disconnect again ( engine off ) connect to spare coil pack with leads and plug attached, start engine, plugs firing cleanly???? One would think a duff coil pack but the one on the engine is the new one!

I am pretty convinced that the ECU coil drivers are on the way out

Anyone know what the actual repair is to the output drivers? Replacing mosfets or something?

Just found this .......
Quote:
SLK (from 1999) C class (from 2002) suffer from 'check engine' light illuminating with PO30/32 codes (misfire). This is caused by defective soldered spur connection in wiring harness (+12V feed to coils). Resolder to rectify.
Anyone know anything about this fix?
nimbusgb is offline  
Sponsored Links
Advertisement
 
Reply

  Lower Navigation
Go Back   Mercedes Benz SLK Forum > Mercedes Benz R170 SLK Class Cars > SLK R170 General Discussion

Bookmarks

Quick Reply
Message:
Options
Upload your files to MEGAUPLOAD
Upload your images to ImageShack

Register Now



In order to be able to post messages on the Mercedes Benz SLK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











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



Similar Threads
Thread Thread Starter Forum Replies Last Post
Only hot air from vents hockeyd4d SLK R170 General Discussion 17 03-26-2017 08:02 AM
slk misfire sportstaaa SLK R170 General Discussion 6 06-26-2015 05:56 PM
hot air from engine comes inside mohamedzamzam SLK R170 General Discussion 6 04-04-2010 09:04 AM

Posting Rules  
You may post new threads
You may 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
 

Clubs, Garage Plus vBulletin Plugins by Drive Thru Online, Inc.