Strange issue with my CLK today. Headed off to work and car started fine, then 2 minutes up the road, I remembered that I'd forgotten something so headed back home. Pulled up outside and ran in the house to grab what I needed (was in the house all of 2 minutes) and then came back out, jumped in the car, and now I just get this noise of presumably the starter motor trying to start the engine, but doesn't actually crank.
I have an ELM327 WiFi OBDII gizmo and an app on my phone called "FourStroke" which pulls up the error codes on the car, and I'm getting a P0112 error code.
Feel like I'm going down the rabbit hole with this one as so far from looking on google, from what I can tell it could be the MAF sensor, the CPS, the fuel pump or an electrical fault! :-(
What's making me think that maybe it's not the CPS is that it doesn't start regardless of whether the engine is hot or cold, and I've read that normally if the CPS is faulty, it will normally work if you let it cool down for half an hour or so. It makes no difference and still won't start even after leaving the car for two hours.
What's making me think its' not the MAF sensor, is that most people say a MAF issue really affects vehicle performance, but won't stop the car from actually starting.
I guess it could be the fuel pump, but wouldn't that bring up a different fault code? I can clear the P0112 code with the app, then turn the key, hear the noise and the error code comes straight back again.
I checked the fuse in the boot for the fuel pump and that looks fine. I also swapped the relay for another identical one I borrowed from the fuse board under the bonnet (Hella 12v 4RA 002 542 26 19) that does another job, but that still didn't work so doubt it's that.
I uploaded a quick video of the noise (unfortunately the sound isn't great - Also please ignore the 3-4 "dunk" noises at the start of the video as that's an unrelated issue of a plastic cog hidden away behind the dash that controls air-con direction...apparently a common fault on the CLK's)
YouTube clip of car not starting
What do you guys think?
What I'm thinking I'll do is firstly change the CPS (this one)
and if that doesn't work, then change the MAF (this one)
and either of those don't work then possibly a new fuel pump?
Any help/advice would be much appreciated!
I wouldn't think it would be that expensive or difficult to rectify that surely (as long as valves and pistons haven't been mating under the cylinder head)?
Again not a major job?Its more finding out why, timing case needs to be removed. I suspect broken guide on the tensioner side.
Again not a major job?
what I don't really understand is how the car can go from working perfectly fine, no issues at all. I drove for a few minutes, realized I'd forgotten something so turn the car back round, pull up outside my house, run in to grab something, come back out 30 seconds later, try to start the car, and now it stops working and the chain is all out of place? from that moment, the car hasn't moved. It was towed to the garage, and since then all that's really happened is a gearbox drop to change the CPS, and an ECU swap-out?
Is it a case that it's been slipping degree-by-degree over time and finally it's got to the point where the car just suddenly decides, "nope, enough is enough, I'm not starting for you!" ?
As I say, it wasn't like the car had issues prior to the fault, it was driving perfectly well
It will run OK but be down on power when the timing is off by 1/2 degrees. Any more and it will refuse to run as the ECU cannot get the correct sync between the cam/crank.
Chains tend to jump when started so its probably done it as you went to crank it.
Hmmmm……sorry to read this its a real downer, the car needs an enthusiast with time and who does not need to incur labor costs then it could turn out ok
Probably a different thing entirely. The chain guides on most modern cars are made from a low friction plastic. Over time and when subjected to oil and heat these have been known to crack or fracture. In your case I suspect the plastic guide has broken up hence the tensioner can no longer tension the chain. If there isn't enough tension on the chain then it can jump teeth on the sprockets (much like a slack bicycle chain can jump teeth).
Now if you're lucky a new guide and chain and all will be right. Irrespective as Alex said the front of the timing cover will need to come off to verify whats happened and change the damaged parts.
Hi Alex, yep it was fine just before I pulled up to the house, so I doubt it was even out by half a degree at the time. ?