Mercedes-Benz Forum banner

1 - 5 of 5 Posts

·
Registered
2008 CLK550, 2012 C300
Joined
·
573 Posts
Discussion Starter #1
Folks,

2004 SLK320 SE, 54k miles

This has happened to me twice.

The first time the weather was very humid and drizzling rain. Parked the car, went into a convenience store returned started the car and noticed immediately a roll in the idle and uneven acceleration. Pop, the CEL light came on. By the time I drove home ~ 4 miles the engine settled out. Cleared the CEL P0306 (misfire). Never happened again.

Saturday morning I am washing the car while the engine is running (warm it up) and I noticed a regular puffing to the exhaust and putting my hand on the car I felt a roll to the idle. Sure enough the CEL light was on. Checked the codes and again P0306. Moved the car forward in driveway to dry it and the idle settled out. Cleared the CEL and again, poof the problem goes away. While the engine was running I was washing the front of the car and did spray water at the grill.


Here is my question:

I bought the SLK in Tampa last August and drove it back to NY through tropical storm Faye. Remember that storm? It stalled and battered FL for over week. I have never seen it rain like that! It was wild. But throughout all that rain the CEL light never came on.

After the first incident I bought the plugs and wires but have not installed them, as the problem seems to disappear.

Anyone have a suggestion as to the occurrence and why the CEL popped on after two rather mild exposures to moisture?

Long post, thanks for taking the time to read,

Zill.
 

·
Registered
C230K Sport Sedan
Joined
·
5,368 Posts
Whats interesting is there's someone on the C forum with basically the same motor having the same exact problem with no fix yet. What may be happening is moisture is getting under the injector harness connector corroding it. They sell a bosch injector harness repair kit so my guess is that it must be common enough for someone to make this.
 

·
Registered
2008 CLK550, 2012 C300
Joined
·
573 Posts
Discussion Starter #3
Thanks Buell,

At this point it seems hardly worth a fix at this point. I doubt that rinsing the car with a mild water jet got beyond the radiator to the harness. I could be wrong though

It engine was running and I thought the car may have ingested some water and got a hiccup. But it seems like allot of water is needed to get beyond the air filters.

Thanks,

Zill.
 

·
Registered
2008 CLK550, 2012 C300
Joined
·
573 Posts
Discussion Starter #4
Thanks Buell,

Afraid to ask but is that a Bosch part and how much? Any chance you have that part number?

Thanks,

Zill.
 

·
Registered
C230K Sport Sedan
Joined
·
5,368 Posts
Go to autohausaz.com and enter you year, model, engine and check under fuel & air systems, then fuel injector repair kit, it's about $8. Just unplug the connector from the fuel injector for #6 and see if it looks corroded. You can try swapping fuel injectors, plugs, wires, coil packs with another cylinder to see if the problem moves, if it does you are lucky, swap the bad component out, if it persists in #6, it's got to be something like wiring harness or you can do a compression leak down test to see if you have a valve problem or head gasket leak.
 
1 - 5 of 5 Posts
Top