E63 Inconsistent Starts
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Junior Member
Joined: Jun 2017
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2008 E63
E63 Inconsistent Starts
I've got a 2008 E63 that sometimes starts inconsistently. Sometimes, I'll push the start button and after a crank, the engine will start right up. Other times, it'll take two.
Any ideas on why this might be? I've never had it not start, but there definitely is some variation in how it does so. No codes.
Any ideas on why this might be? I've never had it not start, but there definitely is some variation in how it does so. No codes.
Super Member
Joined: Nov 2016
Posts: 603
Likes: 275
From: NYC
S63, GLE580, BV250
Since there are no codes it could be anything really, spark, fuel, and/or air. You can start with the cheapo stuff first, make sure battery is providing enough for a strong crank, for fuel maybe toss a bottle of injector cleaner in there or try a different brand, swap out the air filters and hopefully everything is back to normal.
Thread Starter
Junior Member
Joined: Jun 2017
Posts: 46
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2008 E63
Since there are no codes it could be anything really, spark, fuel, and/or air. You can start with the cheapo stuff first, make sure battery is providing enough for a strong crank, for fuel maybe toss a bottle of injector cleaner in there or try a different brand, swap out the air filters and hopefully everything is back to normal.
Thanks for the input. I'm assuming this doesn't happen on your E63? I'm probably going to do all of those things and the plugs since I've just crossed over 75k.
Super Member
Joined: Nov 2016
Posts: 603
Likes: 275
From: NYC
S63, GLE580, BV250
I’m at about the same mileage, in the past I would sometimes get slight hesitation starting up when engine is cold (don’t forget that if it’s parked outside in freezing temps the battery isn’t the same as if it were normal temp). Also, for some reason it’s only when I start with the push button, now I make sure it’s pressed firmly for the entire crank until turnover, haven’t really noticed it when I used the key. I haven’t driven it much during the winter and have it hooked up to a battery tender in the garage. I swapped out my air filters when I did my 5k oil change, threw in some injector cleaner, and haven’t noticed any stumbles or hesitation
If you stay up on the routine maintence and I don’t think it will be much of an issue. I’m coming up on the time to have the plugs, filters (fuel filter too), and all the fluids done.
If you stay up on the routine maintence and I don’t think it will be much of an issue. I’m coming up on the time to have the plugs, filters (fuel filter too), and all the fluids done.
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Junior Member
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2008 E63
Sorry, I meant to say earlier that I've just crossed over 70k, not sure where 75 came from.
I've only had the car about 5 months - the previous owner before me had always taken it to a dealer so I was under the impression everything was up to spec.
I recently had the entire pump assemblies replaced as part of the fuel tank recall.
I'm not sure that holding the button or the key in the crank position does anything. It seems like after the signal has been sent, the rest sort of happens on its own. Simply my speculation, since you can flip the key very quickly to crank and the rest of the ignition sequence still happens.
I'll try the injector cleaner, I've never been a huge believer in them tbh.
I've only had the car about 5 months - the previous owner before me had always taken it to a dealer so I was under the impression everything was up to spec.
I recently had the entire pump assemblies replaced as part of the fuel tank recall.
I'm not sure that holding the button or the key in the crank position does anything. It seems like after the signal has been sent, the rest sort of happens on its own. Simply my speculation, since you can flip the key very quickly to crank and the rest of the ignition sequence still happens.
I'll try the injector cleaner, I've never been a huge believer in them tbh.
Super Member
Joined: Nov 2016
Posts: 603
Likes: 275
From: NYC
S63, GLE580, BV250
Techron never did much for me, I tried jectron and I think it actually did the trick. As for the button and the start signal I was under the same impression but for some reason I got hesitation and switched to turning a key most of the time.
Thread Starter
Junior Member
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2008 E63
Oh man, I totally forgot about Liquimoly. I've been running their 5W-40 and Ceratec for two oil changes now. I'm going to order this for sure. Thanks man. Great to have someone to talk to with similar mileage 
By the way, how many of these do you use at a time?
By the way, how many of these do you use at a time?
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Super Member
Joined: Nov 2016
Posts: 603
Likes: 275
From: NYC
S63, GLE580, BV250
I think its one can per 20 gallons or something like that, I ordered 8 from amazon and just tossed one can in when my fuel level was 1/3 and filled it up from there. I remember reading somewhere that its got some kind of German Department of Transportation (or some gov't agency) approval for use, so I figure its gotta be a good product, everything else I never put much faith in.
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2004 E55 AMG
crank sensor, happened to mine e55.. for it it alway crank right up cold, when it is hot or driven for a while, took couple second to crank, but not always, sometime it will crank up just fine. until I was stuck in usps's parking lot, won't catch, after 20 mins cool down and it crank right back up. threw a code, replaced the crank sender, and the code is gone.
