E400 3.5 long crank HELP
New member here, struggling and hoping for help.
I recently bought a 2015 E400, Uk Spec with the twin turbo 3.5 M276 with 62000 miles.
Since I bought the car, there has been an intermittent long crank with the engine. To the point where sometimes the vehicle won’t start first time, but it always fires up second time. It’s intermittent and only happens after the car is fully warmed up, and then cools down a little. Runs absolutely fine with no check engine lights or codes when checked on STAR.
So far the dealer has replaced battery, crankshaft position sensor, all 4 cam sensors, coolant sensor and they’ve done live diagnostics. All camshaft adjusters are within spec and the fuel pump has been tested and also works correctly.
The dealer has essentially given me two options, either give the car back for a full refund, to be honest I’d rather not do this as I love it and it’s a spec I’ve been looking for, for a long time. Option two is £1500 back from the dealer, who states they’re unwilling to put further time into the car as they’re just too busy (obviously not a MB Main dealer).
At this point I’m thinking are there any repairs that are likely to cost more than £1500 that the dealer hasn’t already tested for. I’m thinking it’s either going to be a super cheap repair and something’s been overlooked, or one of those massive pains that just seems to never get resolved.
Wondering what others would do in my situation.
If I do keep the car, I’m looking forward to getting to know you all on the forums.
Thanks in advance!
I've never had a long-crank situation with it, but every now and then the keyless go will stop working, despite having fresh batteries in the keyfob, but it's always resolved itself. It's impossible to recreate the situation once it starts working again, so I've never bothered to look into it.
Regarding your long-crank situation, I'd take it to a MB dealer or independent MB specialist. Use the dealer rebate to pay for a proper diagnostic.
I've never had a long-crank situation with it, but every now and then the keyless go will stop working, despite having fresh batteries in the keyfob, but it's always resolved itself. It's impossible to recreate the situation once it starts working again, so I've never bothered to look into it.
Regarding your long-crank situation, I'd take it to a MB dealer or independent MB specialist. Use the dealer rebate to pay for a proper diagnostic.
Yeah to be honest this is my thoughts as well. My only concern is the dealer has actually identified the issue and knows the cost to fix and that’s why it’s suddenly not worth it. However from browsing the forums, not many M276 engines fail do they?




Your long crank sounds exactly like a fuel issue pressure is taking a while to build up.
The fuel tank has 2x fuel pumps
The engine has either 1x or 2x HPFP
I would look at running pressures with scanner.
Last edited by CaliBenzDriver; Aug 23, 2024 at 08:17 PM.




