2004 W211 E270 CDI - 'Hissing' Gas noise on acceleration

[SamRhy]

Hello there

I have a 2004 W211 E270 CDI and it has started making a 'hissing' gas release sound when accelerating. It is quite difficult to know exactly where the noise is coming from but there is definately and issue of some sort - any ideas would be greatly appreciated

thanks - Sam

 

[whitenemesis]

Intercooler pipework is a prime culprit.

 

[SamRhy]

Thanks Whitenemesis. I will check the pipework and connections. Assume the intercooler is near the radiator and can be accessed from below the car? cheers, Sam

 

[whitenemesis]

Just below the radiator, there may be an undersheild in the way. Pipework closer to the engine is more likely though, was the case on my C270

 

[SamRhy]

Thanks again Whitenemesis - will give it a go - appreciated...!!
Sam

 

[SamRhy]

Hello there - just to add to this thread some updated information on symptoms of the hissing/whistling noise on acceleration.

I am yet to check the intercooler pipework - planning on doing that over the weekend.

The other symptoms include;

1. Bit smokey on acceleration (due to the tinted glass in rear view mirrors and tending to drive most in the darker hours it's quite hard to gauge this but there is definitely some smoke on acceleration)
2. Power is possibly a bit under what it should be (i don't know for sure as haven't owned the car long, but I have put the car in 'Sport' mode to pull off quicker from standstill as 'C' mode just felt very slow)

Obviously, I need to start doing some checking/diagnosis for proper, but just wondered if this extra info helped to point in the right direction?

Hissing/Whistling noise still there on acceleration.

many thanks in advance

Sam

 

[merc85]

Leaking fuel injector perhaps?

 

[SamRhy]

thanks for the reply merc85.

I discovered a split intercooler hose over the weekend and i have bought a new one to reaplace this weekend. I used gorilla tape to cover the split temporarily. Car seems to be running alot better and lost the hissing/gas noise.

Thanks for all the replies
Sam

 

[Larkone]

Worth replacing the o-ring seals on the intercooler pipes whilst you are at it as they compress over time. Look for oil mist/oily dust around the joints. I didn't have a pipe split but changing the o-rings on mine made a difference to performance.

 

[SamRhy]

Hi Larkone - thanks for the advice

Can I ask where these O'rings are on the car?

Also - would you know where to buy them from ?

Thanks..!

Sam

 

[Larkone]

They are on each joint on the pipes from the turbo to the intercooler. You can only buy them from MB - not found anyone who makes pattern parts. They may have some on the new pipe but if they haven't then you need to source some.

 

[SamRhy]

ok got it cheers - i have just ordered the haynes manual for the car - which will help in general i think
ta