My C300 Horror Story
07-11-2018, 06:47 PM
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2015 C300
My C300 Horror Story
Hello everyone! I'm a long time lurker here and all the information here was very helpful to me when buying my first Mercedes, a 2015 CPO C300 with 25,000 miles on it. I wanted to share my experience I've had a pretty hard time with it so far. The first problems I encountered were a rattle in the driver window and a squeaky gas pedal. These issues were fixed by the dealer with no hassle. Then the check engine light came on. The code that was thrown was P0128, the coolant temperature not as expected. I thought this would be a simple repair. The dealer had it done in one day and I picked it up. After about 100 miles the light came back on with same code. Brought it back to the dealer and this time also mentioned the AC was making a knocking noise when the compressor goes on or off. I wasnt sure if this was an issue as it was a quiet noise but wanted it checked. They found an issue with the AC, replaced vents and valves and told me it was ready to be picked up yesterday. After I left the dealer, the first thing I noticed was the left most vent wasnt blowing air anymore and the AC was making the same noise. Then I go to get on the highway and thats when things went south fast. I suddenly noticed that I had no highway acceleration, even at full throttle, it would still downshift but no power was there. Then the check engine light comes back on. I turned around to go home and suddenly while trying to accelerate the car began misfiring and then shaking violently. At first I thought I blew the motor I could not accelerate at all. I was able to pull over to safety and turn the car off. When I restarted it I was able to drive again but still no acceleration. Now the car was also misfiring constantly at idle. When I got home I checked the codes. The codes we P0299 (Underboost), P0301 (Cylinder 1 misfire) and P0128 (coolant temp again!!!). So I got the car to the dealer this morning and they told me its already all fixed. Im Worried about long term damage to the engine from this mishap it was driving really rough. I was wondering if any of you have had an experience like this and have any advice on what I should look for to make sure this was taken care of. Thanks everyone for your advice!
07-11-2018, 08:56 PM
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07-11-2018, 09:03 PM
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I don’t really want to return it, i just want it repaired and to make sure all the problems have been taken care of. I’m pretty sure all the engine trouble I had yesterday was caused by a screw up by the dealer who did the repair on the AC and not a flaw with the car.
07-11-2018, 09:08 PM
#6
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sorry to hear about all the troubles but I would take my car to another dealer since that last incident was the third strike with coolant code. At least all repairs should be covered by warranty...
07-11-2018, 09:10 PM
#7
Based on your description, if I was you, I would not trust this car anymore.
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07-11-2018, 09:16 PM
#8
My car too misfired after I had the wrist pin repair done. It shouldn't cause much issue long term. The 2015s have a host of issues. Lucky you have long term warranty.
07-12-2018, 09:06 AM
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07-12-2018, 10:50 AM
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So I picked up the car this morning and drove it to work. So far no issues with the engine and it seems to be driving well. One thing is that the AC is still making the same noise which the service techs seemed to think was a problem when they heard it. I certainly don't want them ripping the dash out again for a noise I cant even hear with the radio on. I suppose if it gets worse I still have 4 years of warranty left so I shouldn't worry about it.
07-12-2018, 01:52 PM
#13
So I picked up the car this morning and drove it to work. So far no issues with the engine and it seems to be driving well. One thing is that the AC is still making the same noise which the service techs seemed to think was a problem when they heard it. I certainly don't want them ripping the dash out again for a noise I cant even hear with the radio on. I suppose if it gets worse I still have 4 years of warranty left so I shouldn't worry about it.
07-12-2018, 04:43 PM
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I suggest you should double check the warranty in detail. my understanding is the default CPO warranty is only for powertrain, and it may not cover the AC once the new car limited warranty expires. unless you bought the extended limited warranty, you should repair it ASAP.
07-13-2018, 08:22 AM
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1986 Light Ivory R107 560SL, 2020 Lunar Blue W205 C300 AMG-line
Some guy recently bought a cpo 2015 and he lives in so cal, he has had numerous issues with it and MBUSA has agreed to buy it back under the lemon law. The dealer told him there is no issues but MBUSA said there was definitely something wrong and it couldn’t be fixed so they are buying it back. The dealer even told him they would void his waranty if he came back for the same issue (vibration hell throughout the car). According to him the dealer had the car for over two months or something like that in total. He posted all of this was posted on mbworld
07-13-2018, 09:31 PM
#16
So my 2015 had something similar happen. It ended up being faulty spark plugs, little did I know pieces got into the engine and damaged it. I just found out today Mercedes is giving me a brand new engine. If that doesn’t fix it, might as well light it on fire and start over lol
07-13-2018, 09:57 PM
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So my 2015 had something similar happen. It ended up being faulty spark plugs, little did I know pieces got into the engine and damaged it. I just found out today Mercedes is giving me a brand new engine. If that doesn’t fix it, might as well light it on fire and start over lol
07-13-2018, 10:46 PM
#18
it was actually running fine weirdly enough. Like right after the spark plug deal I thought I felt some blips or something but it was fine after. Ran fine for like 6-7 weeks. But like all of a sudden the car stopped accelerating. I’d have to pull over restart and it worked. I drove it straight to the dealer. They couldn’t read any lights since there wasn’t any. They opened the engine and saw it had damage. Mercedes said to replace the entire engine. And now I’m just waiting.
07-14-2018, 06:25 PM
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I suggest you should double check the warranty in detail. my understanding is the default CPO warranty is only for powertrain, and it may not cover the AC once the new car limited warranty expires. unless you bought the extended limited warranty, you should repair it ASAP.
02-04-2019, 12:38 PM
#20
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My experience with this is that not all dealerships are the same. Some are much better than others. IF the deal cant fix it on the 2nd try, take it some where else specially if you are in warranty!
In regards to not being able to accelerate. Modern cars are built to prevent permanent damage to the engine. So they will go into dumb mode which decreases acceleration, and shut off the car even before it gets to a point where damage can be done. So I wouldn't worry about that. BTW were you regularly filling up 93 octane? or were you using lower octane?
In regards to not being able to accelerate. Modern cars are built to prevent permanent damage to the engine. So they will go into dumb mode which decreases acceleration, and shut off the car even before it gets to a point where damage can be done. So I wouldn't worry about that. BTW were you regularly filling up 93 octane? or were you using lower octane?
02-15-2019, 11:06 AM
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Hey guys. Since this has gotten bumped back up I figured I would post an update to the story. I ended up finding a new dealer to work on the car and they went over the car and fixed all my little complaints including a panoramic roof rattle and burmester speaker crackling. Since then the car has been great and I’m very happy with it. I’ve still got a little over three years with the cpo warranty and I’ll definitely enjoy the car for at least that long.
02-15-2019, 11:30 AM
#24
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When I was reading the first post, my very first thought was "this guy needs to take it to a different mechanic!!!"
sounded like all your issues where shoddy workmanship. (no boost = someone left an intake tube off) That's why the fixes were so simple, because someone just needed to go in and tighten a hose clamp or a connector!
sounded like all your issues where shoddy workmanship. (no boost = someone left an intake tube off) That's why the fixes were so simple, because someone just needed to go in and tighten a hose clamp or a connector!
