Low Power, rough idle...One problem after another. - Mercedes Benz SLK Forum

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

 3Likes
  • 1 Post By CarolinaBluetec
  • 1 Post By fly1705
  • 1 Post By fly1705
 
LinkBack Thread Tools
#1 Old 08-17-2013
Registered Users
 
Join Date: Apr 2013
Location: Australia
Vehicle: 1998 SLK230 Blue
Other Toys: 1963 W111 Fintail, Boat, Models
Posts: 31
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 20
Thanked 5 Times in 3 Posts
Garage
(Thread Starter)
Question Low Power, rough idle...One problem after another.

Hi everyone, Just fixed the roof nicely and now another problem.

Over the last year or so occasionally my '98 SLK230 would idle rough and have low power and I only had to restart it once to fix the problem. Then just lately it decided to stay on for good.
I took it to a workshop for some advice whereby a compression test and readout was performed.Compression good and no codes.It's possible that a coil was suspect but it couldn't be defined.(Both coils have small cracks but no evidence of tracking.) While we were idling the engine and just following a few cables, suddenly the engine ran smooth and full power was restored. We both shook heads, it didn't change, so I left (after one or two engine hesitations) and drove a small distance.

Stopped for an errand, back in the car and it came back...Grrrr.

Now I have done a few things....A brand new Bosh MAF fitted 5 days ago. Also inspected the K40 relay...no sign of burning - but resoldered most of PCB just in case. The car starts and stops easily with normal idle after warmupl. Normal temp. No smokey exhaust. Iridium plugs are 12 months old with less than 10,000klms.

Rough idle, poor acceleration, not nice to drive. Removing plug tops one at a time whilst running did not conclude anything. Any thoughts? I hate paying for parts not required and not many used bits available here in AUS. Any help is greatly appreciated......Barry
fly1705 is offline  
Sponsored Links
Advertisement
 
#2 Old 08-17-2013
Registered Users
 
Join Date: Jun 2012
Location: South of France
Vehicle: R171 SLK 350 (2005)
Posts: 8
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 1
Thanked 1 Time in 1 Post
Hi Barry.
Have you considered the fuel injectors?
I had a '97 SLK 230 (R170) for 12 years before. The only real problem I had with it was with the fuel injectors. Twice! Seven years apart.
The first time: Very rough idle and very powerless. Intense gasoline smell. One of the injectors must have failed in the open position.
The second time: Rough idle and slightly powerless, but not that bad. No smell. The car was drivable. The car dealership had a look at it and said it was the injectors this time too. But I traded in the car for a newer SLK (my current R171) instead of having it repaired, so I can not be 100% sure about the diagnose.
Your case sounds similar to my second time case with the exception that my problem didn't come and go. When it had failed it stayed that way.
mhslk is offline  
The Following User Says Thank You to mhslk For This Useful Post:
#3 Old 08-17-2013
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: 91,733
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
moving to r170 general discussion


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  
 
#4 Old 08-17-2013
Registered Users
 
Join Date: Aug 2013
Location: East Yorkshire
Vehicle: 2008 SLK200 Kompressor Fire Opal 6 Spd Manual
Other Toys: Giant & Planet X Road Bikes
Posts: 203
Country:
Chats: 0
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Thanks: 0
Thanked 21 Times in 21 Posts
Garage
Hi, does your car have an EGR (exhaust gas recirculation valve) fitted? If so try blanking it off for a while. If it's sticking it will may be bleeding exhaust gases back into the inlet manifold when it should not be.
Rooster is offline  
The Following User Says Thank You to Rooster For This Useful Post:
#5 Old 08-17-2013
Registered Users
 
Join Date: Jan 2013
Location: Greenville SC
Vehicle: 2008 E320 Bluetec(sold 11/14), 2001 SLK 320, 2013 E350
Other Toys: 1972 MGB, 2004 Volvo V70
Posts: 287
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Thanks: 2
Thanked 37 Times in 33 Posts
Garage
Since you were following cables and it started working, I would suspect an intermittent break (open circuit) in one of the wires supplying power to a coil or plug. I had this problem on an Audi and it took 3 years to track it down after the dealer threw thousands of dollars in parts at it. What you have sounds like an ignition problem.
Tolak likes this.
CarolinaBluetec is offline  
The Following User Says Thank You to CarolinaBluetec For This Useful Post:
#6 Old 08-17-2013
Per ardua ad cineris.
 
Tolak's Avatar
 
Join Date: Apr 2013
Location: Somerset UK
Vehicle: SLK230 '99 R170
Other Toys: Clio Williams
Posts: 1,039
Country:
Chats: 0
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Thanks: 14
Thanked 136 Times in 117 Posts
As CarolinaBlueTec says, possibly a wiring problem.
Three things might change following a restart:
System reinitialisation; something got confused, and restarting cleared that.
Something cools down, and makes good; unlikely to happen regularly.
Wiring has a break, and teh shake of the engine starting up makes teh wiring good again.

Check wring both on the outgoing and earth (return) paths; put a meter between teh engine block and the negative terminal of the battery when it is misfiring, and if you have any voltage at all, there is your problem.
Tolak is offline  
The Following User Says Thank You to Tolak For This Useful Post:
#7 Old 08-19-2013
Registered Users
 
Join Date: Apr 2013
Location: Australia
Vehicle: 1998 SLK230 Blue
Other Toys: 1963 W111 Fintail, Boat, Models
Posts: 31
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 20
Thanked 5 Times in 3 Posts
Garage
(Thread Starter)
Thanks for your interest. I'll take this on board and investigate further. I'll remove the injectors to have them cleaned and tested. It's a possibility that this could be the culprit but I still think it's something else. Other clues from other members must be followed up as well. Cheers...
fly1705 is offline  
#8 Old 08-19-2013
Administrator
 
Livefreeordie's Avatar
 
Join Date: Oct 2007
Location: Rochester,NH USA
Vehicle: 2002 SLK230K
Other Toys: 1986 560SL, 2012 VW Tiguan, 2017 Ram laramie 1500
Posts: 17,144
Country:
Chats: 27
Mentioned: 83 Post(s)
Tagged: 0 Thread(s)
Quoted: 105 Post(s)
Thanks: 1,097
Thanked 1,292 Times in 1,143 Posts
Garage
Have you looked into the CPS or the fuel filter as the culprit?
Livefreeordie is offline  
#9 Old 08-19-2013
Registered Users
 
Join Date: Apr 2013
Location: Australia
Vehicle: 1998 SLK230 Blue
Other Toys: 1963 W111 Fintail, Boat, Models
Posts: 31
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 20
Thanked 5 Times in 3 Posts
Garage
(Thread Starter)
I wiggled every wire and loom with a decent force while the engine was running with no change. Someone had changed the O2 sensor without soldering but fixing this had no impact. Previously the engine had been idling for a long time during diagnosis and although not overheating, it suddenly corrected itself and we tried moving wiring etc but it stayed good for 30mins or so until a restart. I'd like to think it was a bad connection but not convinced yet. It may be something else.Looking for the EGR valve....if it has one. Might be able to find a pic. Cheers...
Tolak likes this.
fly1705 is offline  
#10 Old 08-19-2013
Registered Users
 
Join Date: Apr 2013
Location: Australia
Vehicle: 1998 SLK230 Blue
Other Toys: 1963 W111 Fintail, Boat, Models
Posts: 31
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 20
Thanked 5 Times in 3 Posts
Garage
(Thread Starter)
Thanks for the clues. Will check and report ASAP. Cheers...
fly1705 is offline  
#11 Old 08-21-2013
Registered Users
 
Join Date: Apr 2013
Location: Australia
Vehicle: 1998 SLK230 Blue
Other Toys: 1963 W111 Fintail, Boat, Models
Posts: 31
Country:
Chats: 0
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 20
Thanked 5 Times in 3 Posts
Garage
(Thread Starter)
Well I solved the problem with the rough idle....couldn't believe it was a faulty iridium plug! They had only done around 10,000km so I presumed they were still in good order. Also the fault was intermittent - not generally what I would expect from a spark plug. Last week two plugs were removed for inspection and some movement of wiring temporarily corrected the problem and I would have thought more of the wiring/coils rather than the plug.Anyway I re-fitted the original (standard?) BKUR6ET-10's and it's back to full smooth power.
So the question is should I have fitted the Denso IQ20 5302 Iridium's in the first place,is there something better, or was I just unlucky?
Thanks for all your thoughts....i will never presume again!
JaysonM likes this.
fly1705 is offline  
#12 Old 08-21-2013
Registered Users
 
Join Date: Apr 2012
Location: Houston, TX
Vehicle: Mercedes SLK 230 2003
Posts: 1,613
Country:
Chats: 0
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 44 Post(s)
Thanks: 226
Thanked 379 Times in 265 Posts
Garage
Glad you sorted it all out! I'd say you just got unlucky. I put Bosch spark plugs in mine and they perform same as the OEM NGKs!
JaysonM is offline  
#13 Old 08-21-2013
Registered Users
 
Join Date: Aug 2013
Location: Atlanta, GA
Vehicle: 2001 SLK 320
Posts: 161
Country:
Chats: 0
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Thanks: 39
Thanked 28 Times in 19 Posts
Trying to find the info again....when I was researching info about issues with my car I came across thread about using platinum plugs and not the iridium. From what I recall they are not completely compatible and cause issues randomly. I do not remember if this was for the M111, m112, M113 engine or all of them. I have the M112 so I know it covered my engine so I changed my order from the iridium to the Bosch platinum. If I find the info again, I will post the thread. I am sure some of the seasoned members here will chime in if I am incorrect or they may be able to find the info quicker. Hope you do not have any new issues anytime soon.
DIYGirl 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

Tags
power loss, rough idle, slk230

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
Might have a problem with my power windows Brian_74 SLK R171 General Discussion 8 08-26-2009 05:33 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.