Too Much Power - PeachParts Mercedes-Benz Forum

rmmagow · #1 08-14-2004, 08:03 PM

In a Diesel ??? Yup. My 83 CD just seems to have too much get up and go compared to my sedan. The CD idles pretty rough and can be made to smoke a fair amount in the driveway while playing around with the throttle. I took it out for a quick ride after some work (not fuel or performance related) and the thing flew!! I mean it was really quick and not even warmed up. Could there be something set wrong in the car? I get about 25 or so mpg pretty much, mostly high speed highway driving. I'm thinking the waste gate might be stuck closed or the ALDA's screwed up or maybe I just have a natural little rocket ship here. Should I be in the least concerned? No bad symptoms with the car other than a rough idle but it does feel a bit too peppy for an old turbo diesel. Has about 207K on it.
Thanks.

whunter · #2 08-14-2004, 08:31 PM

With that you might get some reasonable answers.

Hatterasguy · #3 08-14-2004, 10:06 PM

Wow thats the first time anyone has ever had that problem?

Brian Carlton · #4 08-14-2004, 10:25 PM

Put a "T" in the line between the overboost protection valve and the ALDA and run some tubing into the cockpit. Connect up a boost gauge to the tubing and take the vehicle out for a spin and see what the boost level is. You'll know right away if the wastegate is sticking. Anything over 12 is a problem.

psfred · #5 08-14-2004, 10:48 PM

Has some one "turned up the ALDA" or bypassed the overboost switchover valve? It will reduce your milage somewhat if true.

Peter

DslBnz · #6 08-14-2004, 10:48 PM

I hope she ain't overfueled. Do not push the car harder than necessary until you know the sitch.

Holson Adi · #7 08-14-2004, 11:05 PM

That's my old car

Rough idle? If by rough idle you mean the side-to-side rocking then yeah I tried to deal with that...

Injection Pump Rack Dampener
new motor mounts
new transmission mounts
a valve job
checked the t-chain (A-OK)

got it down a bit but never really got rid of it so I just lived with it.

But yeah.. it was one powerful diesel. I thought it was kinda sluggish when cold though (in winter) [Contrary to the gas 420, which is a rocket when it's cold out]

I think I timed its 0-60 and it was actually around 12 secs or so... so it was.. up to spec.

my mechanic, and another guy that drove it, did comment on its pep though.

Also, its 60-80mph acceleration is pretty fierce ... for a gasser even.

I also believe that its motor is still original...

P.E.Haiges · #8 08-15-2004, 02:19 PM

Holson,

Is the ENGINE still original too?

P E H

Fuzzball · #9 08-15-2004, 04:05 PM

Quote:

Originally Posted by P.E.Haiges

Holson,

Is the ENGINE still original too?

P E H

I've been wanting to post a question about my fuel tank having built up pressure, but I was afraid to do so thinking I may state it wrong....

But...hey....I always feel smarter after being on the board!!

Thanks P E H. (seriously!)

rmmagow · #10 08-15-2004, 08:31 PM

Hi Holson,

Yup, the side-to-side shake. I might swap out the engine shock mount and see if it helps any. I can live with the idle and have been, changing that air cleaner bracket was a miserable job though. Used the car today for the first time in a month or so and it sure does rip for a diesel. Probably the real problem is my other diesel that idles nice but is really a slug until it warms up. It moves ok too, but not as nicely as the coupe. Adjusted the front door too. Nice and even now. I'm going to start the search for the door seals and do them before it gets cold again. I expect to lay up the car this winter for the body work under the front bumper and a few other minor body related issues. I had to run it the entire winter last year due to a timing belt failure in my other car. The old coupe is too nice to be subjected to that kind of torture anymore.

Fuzzball · #11 08-15-2004, 10:03 PM

Just out of curiosity,

Why do they call them Motor Mounts?