Good afternoon Friends!

I am new to MB but love the 05 C230 Kompressor I just bought. Has 36k miles on it and looks great.
My issue is I took the car in for the wire harness recall because I was getting a bunch of different codes and some sluggish performance, which through researching this site lead me to believe thats what it may be.

SO, I took it in...first the stealership called me wanting to change the vacuum pump because it was leaking oil...I did some more research on here and found I could do the repair myself. I told them don't worry about it, i may bring the car back in for that repair.

Next, 2 days later, they call back and say I'm getting a misfire code for cylinder 2. (I was getting that when I took the car in) There are no other cylinder misfires. They switched around the plugs and coils and they determined it only effects cylinder 2. Next they said they need to clean/replace the injector for cylinder 2 for $300+.

I did some research on here but couldnt find any info on that. They said it only does it once in a while and after the car is warmed up. He said if it was something serious with the cylinder it would happen all the time while running. BTW, I added some fuel system cleaner to the car and it seems to help while that tank of gas in in the car.

Is this a DIY job for someone mechanically inclined? Any DIY guides out there?

I greatly appreciate any assistance/guidance with this to save a bit of cash. I know "its a Mercedes" but at 36k miles, should I be having any serious engine issues? I'm changing the MAF, air filter, air inlet hose, plugs, transmission flush & filter, AND now the vacuum pump this weekend...hopefully I can add the injector job to this with some guidance.

Thanks!

- Steve
2005 C230 Kompressor
36k miles

 

Check plugs, coil - seems to have been done. Compression test to ensure you don't have a valve leak. Injector replacement is not difficult to DIY.

Sorry - I only have the V6 procedure which is similar but not the same. It will give you an idea.

https://mbworld.org/forums/attachmen...es-me-sfi-.pdf

 

Thanks for the response. The stealer wants me to pay $180 for them to do the compression test. He said the next step would be the injector clean/replace...

Anyone else got the DIY for the Kompressor? Thanks in advance.

- Steve

 

You are in good hands with Glyn.

36k miles to replace an injector seems off. I would think it was a simple coil pack issue. But realize I don't have your engine. At some point, you will need a spare coil pack. Once the pack is off, check the plug for fouling, I would think if it is an injector issue the plug will read rather white/hot. If the plug electrode looks whitish, It is running lean, and yes you have a faulty injector. But in the excercise you can swap the offending pack and read the plug. If it is not the coil pack, you would need a spare to be safe anyway.

Ed

 

Thank you for the response. I'm going to purchase an extra coil. This may seem like another dumb question but how is the order of cylinders in the Kompressor? Is it 1-2-3-4 from the front?

Thanks again.

 

And another ?
Do I need to change out all 4 or can I just replace the one injector?
OR if I take them off and "clean" them. What do you clean them with, i.e. system cleaner?

Thanks again.

- Steve

 

Yes, number one is the cylinder closest to the front of the car.

You really can't clean the injectors, you have to have it done professionaly. I use RC injectors in California. Injector cleaners don't really seem to work other than a quickie octant boost type of effect, but this is just my opinion.

 

Borrow a compression tester from Autozone. Take all 4 plugs out. Apply full throttle, get someone to crank the engine & read that cylinder. $180

If you require to replace an injector - at your mileage only replace one. They can go a long, long way.

 

Thanks Glyn and Sea....
Would you believe I picked up my car today after they finished the recall work. They told me about the misfire in #2 cylinder and the CEL still on. They told me about the injectors needing cleaned/replaced. They told me they checked the coils & plugs by switching them and said it was a problem specific with #2 cylinder.
So, I get home...change out #2 plug with a new one, turn the key and the CEL is out. Since I changed #2 I figured I'd change them all out. Took like 20 minutes. I took it on a pretty stressfull test run and still no CEL or codes.
I wonder if the stealership was blowing smoke up my A$$ ?? Are these guys that shady?

Anyway, thanks for the help. I may still need to do the injector but I'm not so sure since the CEL went out right after I changed #2 plug.

 

Good News. I was once told that I needed a new stereing rack, but that wasn't true. Thank goodness I didn't pony up the $.

 

Steve - it could well have just been a plug - Stealers!!! As Ed pointed out - very low mileage for an injector problem.

 

SO...to make a long story short the code came back today. The CEL didnt come on but the code came on my reader. P0302 "Cylinder 2 misfire detected"
It didnt come up this morning until I was driving for a bit. This is so frustrating.
What would you recommend? I'll order the coil next but should I order an injector too? I hate blindly throwing money at this.
Any information on replacement of the injector besides the pdf ? Those guides arent very user friendly...
Thanks again for the advice.

add - they have something called a fuel injector repare kit on autohausaz. Should I get this instead of a new injector? Its $9 compared to an injector $50.

- Steve

 

I wish we could trust this stealer. If they have genuinely swapped out a coil & found it made no difference we could go straight to injector replacement. Do not try and refurbish injectors yourself. You need a flow bench to check if they are correct.

That said - having a spare coil is not a bad idea if you intend keeping the car & doing high mileage.

The car seems to run OK - so I suggest doing one thing at a time. Choice of coil vs injector depends on whether you trust the dealer. It is not as though the car will stand.

Maybe we should pop in a new coil first but don't shoot me if we guessed wrong. The M271 engine is coil on plug so there are no HT wires to play up. A LT harness yes - but unlikely to give trouble.

The only reason I am swayed in the direction of the coil is that it is very low mileage to have an injector failure - that said - **** happens.

 

Sounds good. I'll let you know how it goes in a few days when I get the coil.
I changed out the fuel filter today. Pretty easy DIY with the guides from people like you. Greatly appreciated!

 

i had the same problem in my 04 c230k i happened to need a valve job due to a leak in cylinder 2 at the valves . code always read p0302

 

Wonder how things went..

 

Yes, I am also curious on the status of OP. I too, also had CEL come on at 32Kmiles for my 2005 C230k, 6 spd this weekend, Fri 4/1. Same code, P0302. Came straight to this board to see what I can do.

Checked the wireing harness and coil pack, inspected and cleaned plug. CEL still on, so I erased it. Hasn't come back on yet after 50 miles of driving. Does that mean it has been fixed?

 

99% chance the CEL will come back. If it does, follow advice given in this thread such as swapping coils between cylinders first, clearing codes and seeing if the code follows with the coil. If it does not follow, same can be done with 2 plugs. This would be a good start to troubleshooting the code.

 

Cool, thanks. I will do that if the CEL comes back on. Still has not come back on after 1 week and about 300 miles of driving. Although, my drive has become just a little more stressful in anticipation of that damn thing comming on again! LOL

 

You can also scan it now to check for pending codes.

 

what are decent compression numbers for an optimum 05 c230 komp? i did test both wet and dry and got at the lowest 80psi dry then 130 wet on cyl 1...the obdii said misfire detected cyl 1... i have 170,000miles and it started to misfire in that single cylinder. any ideas if this could be injectors or anything?

 

what are decent compression numbers for an optimum 05 c230 komp? i did test both wet and dry and got at the lowest 80psi dry then 130 wet on cyl 1...the obdii said misfire detected cyl 1... i have 170,000miles and it started to misfire in that single cylinder. any ideas if this could be injectors or anything?

 

OUCH!!! CEL light came back on once again for P302 Cylinder 2 misfire. Finally took it to dealership. They did a compression test and said cylinder 2 has low compression (I don't have results) and that I need a valve job. Estimate was for a whopping $4,160!!! YIKES!!

Any advice out there? Has anyone had this done? I have a 2005 C230K w/just under 35K miles. HELP! What are my other options (besides selling)?

 

That quote includes cylinder head replacement. Not common on a 2005 with the redesigned head. Valve fouling with older M271 engines was common. Once fixed you need to run Techron in your fuel.

Post compression values & get a second opinion. I would hate to replace a head for a coilpack or similar problem.

There is a down & dirty trick some dealers did which sometimes blows the deposit off. Run the engine at 5000 RPM unloaded for 1 hour. This is not always effective.

You need to get the valves looking like this:

 

Remember years ago you could buy water injection kits & reservoirs which were supposed to remove the carbon build up from the combustion chamber.