Newbie needs help with CLK55 problem

[Matty77]

Hi people,

I've just joined mbuk in the hope that someone can offer some help with a problem that occured last night while driving.

I haven't posted a newbie intro yet (I'll do that next) but I drive a 2000 model W208 CLK55. He're a couple of pics...

Anyway, back to the problem...

Last night I was out driving her and I was in the mood to hear the V8 growl. Anyway, at one point I was holding her in 2nd gear at about 2500 RPM going for a fast overtake on the car in front. When the road was clear I hit the loud pedal, but instead of increasing revs in 2nd she forced a kick down back into 1st gear. I was completely shocked. I know she will always kick down at gear when you floor the accelerator, but I honestly thought that in this case, the revs and road speed were far too high for a kick down into first.

Anyway, a millisecond later the rev counter needle was at the redline and bounced off the limiter, before the box then changed back into 2nd with the tires franticly hunting for grip. The ESP light flashing for a second or two until they found some.

I was now round the car in front and and I backed off the throttle and knocked the box back into Drive, to cruise along at 1500 RPM because my heart was still pounding through my chest at the sudden kick down incident (anyone who's ever nailed a CLK55 in 1stgear will know exactly what I'm talking about )

So, seconds later, I'm driving sensibly, in Drive, having had all the fun I needed for one evening, when the revs suddenly dropped to around 500 RPM, then picked up again, then dropped, then picked up. Throttle response seemed screwed up too, with my inputs during the rev 'drops' having little effect for a second.

When I got her into the drive. I turned her off, then started her again. In Park at tickover the revs fluctuated erratically between 500-1500. Then got lower until she eventually stalled and cut out. If I hit the accelerator during these fluctuations the revs would increase accordingly, but lumpy, like a misfire.

So I went inside for a coffee, worried that I'd somehow broken my beloved AMG.

This morning, when she was cold I thought I'd try again. I thought the problem had gone away when the revs held at at steady, normal, 1500 RPM during the cold start up mode. Smooth as silk. No problem. That was until the temps rose and she returned her 'normal' idle speed, in Park, of 750 RPM. The revs dropped as normal as she warmed but then the erratic fluctuations returned, revving from 500-2000, up and down, until stalling when the needle hit 0.

So that's where I'm at with her and I'm hoping somebody can give me some advice as to what may be the cause and the fix.

I have a great Indy Merc garage 5 miles away. But I'm reluctant to drive her as she is.

Can anyone shed any light? I'd be really grateful.

Thanks for reading and I look forward to your comments and any advice you can offer a very worried CLK55 ownwer!

Cheers

 

[BlackC55]

Hi people,

I've just joined mbuk in the hope that someone can offer some help with a problem that occured last night while driving.

I haven't posted a newbie intro yet (I'll do that next) but I drive a 2000 model W208 CLK55. He're a couple of pics...

Anyway, back to the problem...

Last night I was out driving her and I was in the mood to hear the V8 growl. Anyway, at one point I was holding her in 2nd gear at about 2500 RPM going for a fast overtake on the car in front. When the road was clear I hit the loud pedal, but instead of increasing revs in 2nd she forced a kick down back into 1st gear. I was completely shocked. I know she will always kick down at gear when you floor the accelerator, but I honestly thought that in this case, the revs and road speed were far too high for a kick down into first.

Anyway, a millisecond later the rev counter needle was at the redline and bounced off the limiter, before the box then changed back into 2nd with the tires franticly hunting for grip. The ESP light flashing for a second or two until they found some.

I was now round the car in front and and I backed off the throttle and knocked the box back into Drive, to cruise along at 1500 RPM because my heart was still pounding through my chest at the sudden kick down incident (anyone who's ever nailed a CLK55 in 1stgear will know exactly what I'm talking about )

So, seconds later, I'm driving sensibly, in Drive, having had all the fun I needed for one evening, when the revs suddenly dropped to around 500 RPM, then picked up again, then dropped, then picked up. Throttle response seemed screwed up too, with my inputs during the rev 'drops' having little effect for a second.

When I got her into the drive. I turned her off, then started her again. In Park at tickover the revs fluctuated erratically between 500-1500. Then got lower until she eventually stalled and cut out. If I hit the accelerator during these fluctuations the revs would increase accordingly, but lumpy, like a misfire.

So I went inside for a coffee, worried that I'd somehow broken my beloved AMG.

This morning, when she was cold I thought I'd try again. I thought the problem had gone away when the revs held at at steady, normal, 1500 RPM during the cold start up mode. Smooth as silk. No problem. That was until the temps rose and she returned her 'normal' idle speed, in Park, of 750 RPM. The revs dropped as normal as she warmed but then the erratic fluctuations returned, revving from 500-2000, up and down, until stalling when the needle hit 0.

So that's where I'm at with her and I'm hoping somebody can give me some advice as to what may be the cause and the fix.

I have a great Indy Merc garage 5 miles away. But I'm reluctant to drive her as she is.

Can anyone shed any light? I'd be really grateful.

Thanks for reading and I look forward to your comments and any advice you can offer a very worried CLK55 ownwer!

Cheers

I would say you either have an air mass sensor issue, throttle body or some kind of intake leak.

It needs a star diag test.

 

[Matty77]

I would say you either have an air mass sensor issue, throttle body or some kind of intake leak.

It needs a star diag test.

A trip down to my indie tech first thing in the morning is on the cards!

Cheers buddy

 

[astamir]

I would say you either have an air mass sensor issue, throttle body or some kind of intake leak.

It needs a star diag test.

As always blackc55 first in response thanks for your big help mate

 

[Lxb3]

...and be careful with that subtle screw positioning on the number plate, you don't really need to give them any additional reason to pull you over!!

 

[Matty77]

I would say you either have an air mass sensor issue, throttle body or some kind of intake leak.

It needs a star diag test.

I think I found it! Thanks to your help. I thought I'd check around the engine for any obvious hoses that might be lose or split, and when I lifted the engine cover I saw a small hose that had popped out of where it should have been. This is the hose...

So I cleaned up the pipe and pushed it back into place and when I started the car she was back to normal. Turned her off. Put the front engine cover back on and took her for a spin. Everything seemed fine and back to normal. I can't believe my luck!

But if you hadn't of mentioned the intake leak I wouldn't have bothered checking all the pipes. I owe you one mate!

Just to satisfy my curiosity, what is that pipe and what does it do? I'd be interested to know.

Anyway, thanks again for your advice buddy. Much appreciated

 

[Matty77]

...and be careful with that subtle screw positioning on the number plate, you don't really need to give them any additional reason to pull you over!!

You know what? I like to live dangerously

I actually live in Manchester and see a lot of police on my daily drives and I've never been pulled for the plate issue. I guess they are just too busy up here with 'proper' crime to worry about such trivia

In fact, just recently a police traffic car parked up next to me in my local McDonalds and one of the officers spent a good five minutes admiring the AMG. He said he thought the car was in amazing condition and commented on how much work it must take to keep her nice.

Anyway, we talked cars for five minutes while the other officer went in to get the burgers and then they said goodbye and left. No mention of the plate screws!

So thanks for the warning, but I think I'll enjoy living life on the wild and dangerous side just a little longer

 

[Lxb3]

Haha... no worries. Just watch out for the jobsworths, that's all I'm saying!

 

[Abdul]

Hi pal, glad you sorted it.

It was me who pm'd you on DW regarding the car!

Still looks fab I see!