Slight misfire
Slight misfire
Hi chaps,
My car (84k on the clock) has had a recent full service. Plugs, oil & filters, fuel filter etc.
Now, before it was serviced it ran fine.
However, since the service it now runs slightly rough at idle (this was immediately after the service and not a few days later) whether in N or D.
When driving it's super smooth, no issues at all.
Seems a bit of a coincidence to me that it was ok before being serviced, and plug replacement should have made it even better if anything. The garage I use are very good, but due to work etc, I just don't have time to take it back in. All plug leads seem to be on tight.
Any ideas what it may be?
My only guess at this time is that maybe I had a lead or two on the way out and disturbing them to change the plugs has made them worse?
My car (84k on the clock) has had a recent full service. Plugs, oil & filters, fuel filter etc.
Now, before it was serviced it ran fine.
However, since the service it now runs slightly rough at idle (this was immediately after the service and not a few days later) whether in N or D.
When driving it's super smooth, no issues at all.
Seems a bit of a coincidence to me that it was ok before being serviced, and plug replacement should have made it even better if anything. The garage I use are very good, but due to work etc, I just don't have time to take it back in. All plug leads seem to be on tight.
Any ideas what it may be?
My only guess at this time is that maybe I had a lead or two on the way out and disturbing them to change the plugs has made them worse?
Re: Slight misfire
Yep, probably so. I went to the Magnecor's at 50k miles.
Here's an OEM replacement set pretty cheap with a "make an offer"
shipping will most likely cost more than the wires
http://www.ebay.com/itm/Spark-Plug-I...3D272720357496
The Magnecor's are a bit more expensive :
http://www.ebay.com/itm/Magnecor-652...1YZeh7&vxp=mtr
Here's an OEM replacement set pretty cheap with a "make an offer"
shipping will most likely cost more than the wires
http://www.ebay.com/itm/Spark-Plug-I...3D272720357496
The Magnecor's are a bit more expensive :
http://www.ebay.com/itm/Magnecor-652...1YZeh7&vxp=mtr
Last edited by ala_xfire; 08-06-2017 at 08:24 AM.
Re: Slight misfire
Just been looking at these.
Whats odd though, is I always thought our cars have 8 of the shorter leads with 4 longer. This shows the opposite? - I may have to email them and ask.
RED 8MM PERFORMANCE IGNITION LEADS MERCEDES M112 320 280 240 SL S E C CROSSFIRE
Whats odd though, is I always thought our cars have 8 of the shorter leads with 4 longer. This shows the opposite? - I may have to email them and ask.
RED 8MM PERFORMANCE IGNITION LEADS MERCEDES M112 320 280 240 SL S E C CROSSFIRE
Join Date: Jun 2009
Location: Fort Worth, Texas
Age: 64
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Re: Slight misfire
I would say wire also.
When I changed my plugs, almost half of them seemed glued on, never seen clips in the boot so tight.
It is hard sometimes especially when getting frustrated, not to grab onto the wire to help pull, but if pulling on wire instead of the boot, the wire can pull out of the socket that clips on the tip of the spark plug.
You could take each one off and inspect and test ohm to see if connection is good.
Or just buy another set.
When I changed my plugs, almost half of them seemed glued on, never seen clips in the boot so tight.
It is hard sometimes especially when getting frustrated, not to grab onto the wire to help pull, but if pulling on wire instead of the boot, the wire can pull out of the socket that clips on the tip of the spark plug.
You could take each one off and inspect and test ohm to see if connection is good.
Or just buy another set.
Re: Slight misfire
Yep, probably so. I went to the Magnecor's at 50k miles.
Here's an OEM replacement set pretty cheap with a "make an offer"
shipping will most likely cost more than the wires
Spark Plug Ignition Wire Set for Mercedes Benz C-Class E-Class ML SLK 320 350 | eBay
The Magnecor's are a bit more expensive :
Magnecor 65211 KV85 Competition 8.5mm Plug Wires
Here's an OEM replacement set pretty cheap with a "make an offer"
shipping will most likely cost more than the wires
Spark Plug Ignition Wire Set for Mercedes Benz C-Class E-Class ML SLK 320 350 | eBay
The Magnecor's are a bit more expensive :
Magnecor 65211 KV85 Competition 8.5mm Plug Wires
Re: Slight misfire
It is possible that the trouble lies somewhere else, is the engine cover on the MAF housing correctly for instance? If not this causes problems. Just saying.
Re: Slight misfire
Some guys of a certain age welcome a nice miss in their lives. The missus might not like it but if you are up to it good luck.
Re: Slight misfire
With a miss I pull all the wires so they are loose then disconnect them one at a time to localize the miss PLUG.
I also never put plug wires back on till BOTH ENDS have been treated to dielectric grease so they can be removed later. They can stick on and then fail when you yank them off, old guy stuff. Woody
I also never put plug wires back on till BOTH ENDS have been treated to dielectric grease so they can be removed later. They can stick on and then fail when you yank them off, old guy stuff. Woody