I've read several of the threads about W209 not starting issues. Mine seems a little different than those. I'm still searching and reading them though. Here's what I have...

2007 clk350 - Took it to get tires, they pulled it out and parked it, seconds later I get in it and it won't start. I need help tracking down the issue. Here are all the history and facts:
1) I replaced the intake recently. Ran fine for a week afterwards.
2) The key turns all the way to "start" so I am getting authorization
3) I cleared codes and read them again and NOTHING is showing
4) I hear some relays clicking in the fusebox under the hood
5) I've checked all fuses in all three panels. None bad
6) I swapped all of the relays that had a similar relay. I think there was one that didn't
7) It doesn't even try to engage the starter
8) the fan doesn't come on (like it did in one of the threads I read)
9) I replaced the battery (just in case)
10) I have full power in the car (the top, the dash, etc)
11) I show P for park on the dash and I can change gears and put it in neutral
12) I had the startup rattle, was going to replace the tensioner right after the tires, never got a chance to

I was getting a couple codes for the past week. ran ok with them though. Note after i cleared them when it wouldn't start, these didn't come back
Pending - P0023 B camshaft position actuator control circuit
Pending - P0025 B camshaft position timing over retarded bank 2
Confirmed - P0106 MAP Sensor circuit range/performance

some of these may have been due to the work I did: (Note after i cleared them when it wouldn't start, these didn't come back)
Low cost tele-aid code - U1669 Not present the Diagnostic CAN network management is unstable (Could have been from disconnecting things)
P1204 The position of the exhaust camshaft (cylinder bank 2) is implausible relative to the position of the camshaft
U0101 - lost communication with the TCM

I don't know which relay is the starter relay. I do know how to use a multimeter. I just need help with test points to track down the failure.

 

Update: Found some online resources and ordered the WIS. Located the starter relay, I'll confirm it is good tonight. However it is one of the ones I swapped, so it should be good.

I Also ordered a couple of Cam Position Sensors (just in case)

 

I checked the timing today. I don't have much experience with these cars. What do you guys think of these photos?


This is the crank at 305

Bank 1



Bank 2 intake cam

Bank 2 exhaust

 

More information - My remote key will not unlock or lock the car using RF. It does work using the Infra red at the handle. Any chance this is related?

 

The remote not unlocking the car is more likely the remote battery of the RF receiver. I don't think it would have anything to do with it not even attempting to crank.

I don't think the cam position sensor would cause it to not crank either.

One of the more experienced members will have to help you with the troubleshooting.

 

My 2009 CLK550 had been sitting idle for a while due to the lock-down, and when I went to fire it up, the starter cranked but the engine did not start. Turned out there was dirt in the fuel tank, that had fouled the fuel pump. Since the price of a new fuel pump was rather steep, I opted to follow the advice of my shade-tree mechanic, to install a V8 Toyota fuel pump as a DIY substitute for the OEM fuel pump . Very skeptical that such a hare-brained idea could ever work, I went with that plan, and to my amazement the car again fired right up, and proceeded to run as smoothly and powerfully as it ever has. It remains to be seen whether there might be long term penalties for using a Toyota fuel pump in a V8 Merc, but so far, this village mechanic solution appears to have worked.

I guess the upshot of my tale, is that IF the OP's car had been sitting for a while without being started up, there might be an issue with the fuel pump, arising from sediment in an old tank of gas. That said, I would NOT recommend that anyone use a non-standard fuel pump in a C209, unless you reside out in the sticks of Africa like I do, in which case, the concept of "any port in a storm" would apply when all else fails.

 

I'm pretty sure at this point it is a bad starter. I tapped on it with a breaker bar and then tried to start it and it tried to engage for a split second, which it had not been trying to do before. Previously, it was dead silent (other than relays) when I tried to start it.

The RF unlock wasn't working because the battery was low in the car. The bad starter was draining the battery and the car shut off the RF antennae when it got low. I charged the battery and it works again.

I am picking up the new starter today and replacing it this weekend.

Hopefully this helps someone else.

Thanks for the replies and help everyone!

 

I got the starter replaced. It was bad. It's running again now.

 

My 2008 CLK550 does not start after sitting for 18 months. It cranks but not start. I am getting 55 psi fuel pressure at the fuel rail. The car was in an accident and I had to replace the front guard bumper, radiator, evaporator, power steering pump, and other parts. I replaced the spark plugs (looked rusty) and will change the oil and gas before I start again. If all fail, then fuel pump? Any advise? Thanks