C43 AMG Only running 235 HP

porterada

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Just wanted to get some thoughts on what could cause lower than expected power output on my C43.... I know its getting on a bit now but from the stated 302hp from new it does seem that a number of horses have bolted.. I do not get any Check engine lights, and have scanned the ecu for faults with none showing. I always put Premium Unleaded. so am wondering If i'm looking at MAF issues or something more serious.
 

C350Carl

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Maf Sensor, Air Filters, Possible injectors clogged a bit.

It does seem to have lost a lot at nearly 70bhp. What year is it?
 

brandwooddixon

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It could be several factors, but with an old vehicle injector wear is an often overlooked cause of power loss.
Other than that you have usual suspects (as mentioned) including obstructions in the exhaust e.g. clogged catalyst or muffler material blocking the flow.
 
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porterada

porterada

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c43 power loss

Its a 99. Just ticked over 100k. Its got a full mb service history and i make sure my cars are always well maintained. Its a weird one as i would expect some sort of pinking or rough idle with that sort of loss. The only thing i notice is on the right bank there is a ticking sound but that just could be normal. Its noticeable on idle. But i guess with these issues its just a case of replace and test. As no error codes are being thrown up
 
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L John

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Would star show if it's getting full accelerator travel?
Worn cams will cause less lift for intake and exhaust and would rob a lot of horses but it would still run nice at lower RPM where restricted breathing wouldn't as much of a problem.
Intake filters should be ok but cats could be breaking up as already suggested.
 

Uncle Benz

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Does it feel down on power? Do you have the dyno print out?
 
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porterada

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c43

It does feel down on power. Its not breaking traction in the dry when i nail it from standstill. It still sounds just as sweet. I popped a couple of k&ns i. To see if it made any difference as i suspected clogged air filter but not really made any difference.
 

WG M-B

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Strange! I find the old v8's get quicker the looser they get !
 
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porterada

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I think i need to get it to someone who specializing in tuning mercs. Any one recommend anywhere near slough?
 

bigasotonuk

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My 43 only did 225, this and your 235 figure is power actually at the wheels, the quoted 306BHP (302BHP is North American cars) is the power generated at the flywheel. The BHP loss is through the drive train, gearbox, Torque convertor, Diff etc.
Olly of PCS had his measured at the same time as mine was done, one owner, 60-70k miles with FMBSH and his was 230BHP (same rolling road that mine was measured on), so I do not think you have anything to worry about. You also want to bear in mind that rolling roads can be grocely inaccurate and should really only be used as an indicative figure, for instance I had mine measured and calculated at 380BHP (after fitting a 55 engine as well as other mods) at one particular rolling road and was told by another customer if it had been done at another rolling road it would of almost certainly had hit 400BHP, as this one was well known to read low.
Flywheel figures cannot be measured with a conventional rolling road only calculated and most give graphs for both actual measured power at the wheel and calculated flywheel power
 
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WG M-B

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There was a decent tuning company in uxbridge many years ago 'power engineering'
Not sure if they are still there. I'd be happy to take a look but I'm nowhere near slough!!!
I do know a bit about C43's though. Got one myself :)
 
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porterada

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Sorry i should have said. The out put i quoted was related to flywheel. Ar the wheels it was showing 195 :(
 
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porterada

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There was a decent tuning company in uxbridge many years ago 'power engineering'
Not sure if they are still there. I'd be happy to take a look but I'm nowhere near slough!!!
I do know a bit about C43's though. Got one myself :)

Yeah that's where i went but looks like they just specialise in subaru mitsus and fords. I really want to get it looked at by some one who knows mercs and amgs
 

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Sorry i should have said. The out put i quoted was related to flywheel. Ar the wheels it was showing 195 :(

Ouch!
I'd never put my car on the dyno unless its a figure to compare on the same dyno after mods are done.
I use dynolicious on the iphone to measure the 0 to 60.

Have you had any mods done, eg exhaust mods for sound?
Not sure if you lost horses or someone swapped them for ponies.

Has this been a long gradual loss or much more sudden?
 
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porterada

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No mods apart from air filters. Now that i think about it i do think it has been a gradual decline i mean most of the time i am on eco driving mode. But every now and then I do give it some. And where as 6 months ago on a dry road it would bring on the traction control light from standing start and even shifting first couple of gears. Now it seems to be reving ok but just not with the same savageness
 

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If you have no record of it being replaced, I'd be inclined to try a new MAF and bootstrap the ecu. They will often not throw a fault code, and the gradual deterioration is rarely noticed until it starts to affect the gearchanges. Speaking of which, do the gearchanges feel normal? A deteriorating MAF will sometimes make them erratic or reluctant to upshift.
 
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porterada

porterada

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I was thinking maf too. The upshift thing is an interesting point. I have noticed some weird things. Like on full throttle it used to really bolt forward at each upshift. But it does seem now more relaxed when going up the gears. And on normal driving after car warms up its like if its still on cold start as it seems to hang in each gear. Like it is supposed to when warming up.
 
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porterada

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Thanks for the comments, i am picking a MAF up this morning, Will report back soon as its installed... :)
 
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porterada

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Well that made it worse lol. Brand new Bosch maf and now got rough idle and all sorts of hesitation. Still no cel though
 

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