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2014 CLA 45 AMG
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Discussion Starter · #1 ·
Hi there
Im Craig from NZ and new here. I have been searching on your forums here and not seen anything that looks to fix my fault. I have a CLA 45 AMG 2014 which is not making power. Seems to drive ok crusing around, smooth driving. Just full throttle it is not making power and takes a long time to rev out. Seems like its not making high boost.

Ive already had the vac solenoid replaced and the boost control solenoid replaced, but same fault. My mechanic seems lost on the issue hence I am reaching out here. The car is out of warranty, so want to not keep taking it into the shop to spend money and not have it resolved.

Anyone here seen this particular issue?

Cheers
Craig
 

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Welcome to the CLA Forum Craig XIVIX :)
Tell the members a little more about your CLA _
a) What is your mileage?
b) When was it last at your MB dealer for regular scheduled service?
c) How long have you owned your CLA?
d) Shouldn't your next step be to look for codes?
 

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2014 CLA 45 AMG
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Discussion Starter · #3 ·
Thanks Geo K!
My CLA has 106,000km on it, its a bone stock sedan. In NZ we have 98 octane, so it runs off this. Its a NZ new model. Often our cars are imported from Japan, but not this one.
The last time it was at Merc was 10,000km ago for a thermostat replacement and service. I've not had this one long, around 4 months and it more or less faulted right away upon ownership which is unfortunate. My OBD II code scanner doesnt appear to work with the car. I have been to a dealership outside of Merc, a European specialist, but they are saying its not dropping any codes. Its not showing a CEL. Just not making power. But runs smooth and drives around ok. Only the two above solenoids have been replaced. Currently I am resetting the ECU in a desperate attempt to that maybe a relearn will help the new solenoid install. But think I shouldnt have high hopes.

Anyone else had a similar issue?
 

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Does your code reader manual indicate the need/availability of a download for Mercedes?
At 10,000km, you are close to the point of needing service, so IMO have MB run a diagnosis at that time and tell them you need the list of codes.
Other members will see this and offer their own advice/opinions.
 

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Whats the air inlet path and components look like? From the scoop to the turbo ...
 

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2014 CLA 250 4MATIC ✨
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Whats the air inlet path and components look like? From the scoop to the turbo ...
Yeah you may have a hole in your intake. Try checking it out if not. When you say not making power do you mean you can go past a certain amount of speed or??
 

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Your CLA is definitely making power, otherwise it won't be driving around. :)

I assume you are not getting any boost when you step on the gas hard??

Okay, some assumptions:
1. you have fairly new engine oil and filter
2. you are running the correct octane gas, which should still give you boost even if you ran regular or mid-grade gas, just not the optimum boost
3. you have a clean air filter (check it anyway, clogged air filter really robs engine power, but does not throw any CELs)
4. your catalytic converter is not messed up (or clogged), won't really throw a CEL immediately if it's only partially clogged
5. your combustion internals are still within specs (pistons, valves, valve springs etc... not worn) again, these won't throw a CEL in general.
6. Assuming no engine leaks, gaskets are good. (Loss of compression leads to drop in power again).

Are your spark plugs good? Have they ever been changed out at say ~ 100,000km?
If yes, were they original Mercedes part? I learned the hard way that you need original mercedes spark plugs and not NGK oem. Trust me , for whatever reason, mercedes has their parts spec'd differently from oem.

I am sure your mechanic can check if there are any leaks in the turbocharging system.

Are your fuel injectors good? Partially clogged fuel injectors will not throw CEL, but definitely reduce overall performance , especially at the top end of the rpm.

Do you regularly use a top-tier gas or petrol? Overtime, combustion deposits will collect and decrease the efficiency of how fuel is burned, again a drop in power without throwing any CEL. You can try throwing in a very powerful combustion cleaner like BG-44K, two consecutive bottles, and it should take care of > 90% of the deposits , including the injectors and valves.
 

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2014 CLA 45 AMG
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Discussion Starter · #9 ·
Yeah you may have a hole in your intake. Try checking it out if not. When you say not making power do you mean you can go past a certain amount of speed or??
That’s a good idea. I have checked over the intake briefly. But perhaps now I need a more thorough inspection. It’s not speed limited. It’s just perky on take off but then feels like it’s low boost through the rev range. So it’s like up to mid throttle it’s all good but beyond that, mid throttle to WOT it offers nothing else. Perhaps throttle position sensor is kaput?
I have heard advice of not going to an independent European car specialst as they can’t read the codes. So maybe it is showing a code but only the merc dealership can see this? There’s no cel though ever. Might be time for me to go to the dealer and prepared for my wallet to get a hammering. :)
 

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Discussion Starter · #10 · (Edited)
Your CLA is definitely making power, otherwise it won't be driving around. :)

I assume you are not getting any boost when you step on the gas hard??

Okay, some assumptions:
1. you have fairly new engine oil and filter
2. you are running the correct octane gas, which should still give you boost even if you ran regular or mid-grade gas, just not the optimum boost
3. you have a clean air filter (check it anyway, clogged air filter really robs engine power, but does not throw any CELs)
4. your catalytic converter is not messed up (or clogged), won't really throw a CEL immediately if it's only partially clogged
5. your combustion internals are still within specs (pistons, valves, valve springs etc... not worn) again, these won't throw a CEL in general.
6. Assuming no engine leaks, gaskets are good. (Loss of compression leads to drop in power again).

Are your spark plugs good? Have they ever been changed out at say ~ 100,000km?
If yes, were they original Mercedes part? I learned the hard way that you need original mercedes spark plugs and not NGK oem. Trust me , for whatever reason, mercedes has their parts spec'd differently from oem.

I am sure your mechanic can check if there are any leaks in the turbocharging system.

Are your fuel injectors good? Partially clogged fuel injectors will not throw CEL, but definitely reduce overall performance , especially at the top end of the rpm.

Do you regularly use a top-tier gas or petrol? Overtime, combustion deposits will collect and decrease the efficiency of how fuel is burned, again a drop in power without throwing any CEL. You can try throwing in a very powerful combustion cleaner like BG-44K, two consecutive bottles, and it should take care of > 90% of the deposits , including the injectors and valves.
That’s correct. Step on it hard and it seems to spool quick and then that’s it. Feels like no high boost but it could be a throttle issue of some sort. The car is smooth. Doesn’t run rough which I’d expect from a fuel issue.
I run 98 octane the highest we get in NZ full time in the car.
Plugs I am not sure when they were last changed but again the car would run rough and miss if ignition was the issue. The car is very smooth.
Loss of compression again would lead to rough running which the car doesn’t do. Definitely doesn’t feel like compression loss. Usually that’s like a dog when that happens.
Far as I’m aware the internals are stock and wouldn’t expect I need to rip off the head to inspect it over this issue. If anything was worn to that degree I’d probably also be seeing a lot of smoke out the rear. It doesn’t smoke at all.

Oil and filter could use a change but again I don’t see how that will result in the reduced performance. Not as dramatically as I am getting. My supercharged Mini Cooper would beat this thing in a race at the moment to put some perspective of lack of performance I’m seeing.
It’s a curious one. I might just need to bite the bullet and head to merc to see what codes they get.
Question. If the car was in limp mode. It would display a cel right?
 

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That’s correct. Step on it hard and it seems to spool quick and then that’s it. Feels like no high boost but it could be a throttle issue of some sort. The car is smooth. Doesn’t run rough which I’d expect from a fuel issue.
I run 98 octane the highest we get in NZ full time in the car.
Plugs I am not sure when they were last changed but again the car would run rough and miss if ignition was the issue. The car is very smooth.
Loss of compression again would lead to rough running which the car doesn’t do. Definitely doesn’t feel like compression loss. Usually that’s like a dog when that happens.
Far as I’m aware the internals are stock and wouldn’t expect I need to rip off the head to inspect it over this issue. If anything was worn to that degree I’d probably also be seeing a lot of smoke out the rear. It doesn’t smoke at all.

Oil and filter could use a change but again I don’t see how that will result in the reduced performance. Not as dramatically as I am getting. My supercharged Mini Cooper would beat this thing in a race at the moment to put some perspective of lack of performance I’m seeing.
It’s a curious one. I might just need to bite the bullet and head to merc to see what codes they get.
Question. If the car was in limp mode. It would display a cel right?
If the car is on limp mode you’ll know right away. It won’t let you go past like 20mph and it’ll also say something in the screen depending on the issue it can go on limp mode with speed and then it can go limp mode as in traction control off, abs off and 4matic off and I’ll turn into a front wheel drive car and start driving a little funky.
 

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That’s a good idea. I have checked over the intake briefly. But perhaps now I need a more thorough inspection. It’s not speed limited. It’s just perky on take off but then feels like it’s low boost through the rev range. So it’s like up to mid throttle it’s all good but beyond that, mid throttle to WOT it offers nothing else. Perhaps throttle position sensor is kaput?
I have heard advice of not going to an independent European car specialst as they can’t read the codes. So maybe it is showing a code but only the merc dealership can see this? There’s no cel though ever. Might be time for me to go to the dealer and prepared for my wallet to get a hammering. :)
Try to check everything before you go! Even if it’s small it’ll probably be expensive!
 

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That’s correct. Step on it hard and it seems to spool quick and then that’s it. Feels like no high boost but it could be a throttle issue of some sort. The car is smooth. Doesn’t run rough which I’d expect from a fuel issue.
I run 98 octane the highest we get in NZ full time in the car.
Plugs I am not sure when they were last changed but again the car would run rough and miss if ignition was the issue. The car is very smooth.
Loss of compression again would lead to rough running which the car doesn’t do. Definitely doesn’t feel like compression loss. Usually that’s like a dog when that happens.
Far as I’m aware the internals are stock and wouldn’t expect I need to rip off the head to inspect it over this issue. If anything was worn to that degree I’d probably also be seeing a lot of smoke out the rear. It doesn’t smoke at all.

Oil and filter could use a change but again I don’t see how that will result in the reduced performance. Not as dramatically as I am getting. My supercharged Mini Cooper would beat this thing in a race at the moment to put some perspective of lack of performance I’m seeing.
It’s a curious one. I might just need to bite the bullet and head to merc to see what codes they get.
Question. If the car was in limp mode. It would display a cel right?
Does this happen in eco, sport mode or manual?
 

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Discussion Starter · #15 ·
Does this happen in eco, sport mode or manual?
Yeah it happens across all modes which is a bummer. I’m going to spend some time over the weekend checking the intake properly. Although when it was in the shop I would have expected them to do that as well. It was in there for a month as they waited on parts from Germany. That was for the boost solenoid. I’ve spent over 2k NZD on it already for the same fault. :(
 

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Yeah it happens across all modes which is a bummer. I’m going to spend some time over the weekend checking the intake properly. Although when it was in the shop I would have expected them to do that as well. It was in there for a month as they waited on parts from Germany. That was for the boost solenoid. I’ve spent over 2k NZD on it already for the same fault. :(
Keep us updated! I got my car back from Mercedes Benz with the hole in my intake, I ended up getting upset and just buying an aftermarket one 😝
 
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