2 E420’s – 1 fast, 1 slow. Whats up?!?!

[AtlBenz]

Okay guys, here is the deal.

I’ve got two 1994 W124 E420’s. A taupe (?) one and a white one (as seen HERE ). Driving both back to back, its very obvious that the white car has a significant power loss. The car dosent seem to have trouble moving up in the RPM, but it just doesn’t GO. It feels “dull” or “heavy.” Like something is being retarded.

rotors, caps, and plugs are new. No check engine light.

I searched a bit and read something about oil tubes. What are they? Where are they? And how do I get to them? How do I test or know if they are bad? The oil pressure gauge reads fine.

Now, the taupe car has had the throttle actuator recently replaced - much thanks to the previous owner for dropping $1400 on that! But the white car isn’t showing symptoms of a bad actuator (no surges, no weird RPM changes, no stalling problems.) Neither car has ASR.

Basically the white car is perfectly fine…..except SOMETHING is holding it back.

BTW are these cars supposed to idle around 500? Both of them do it, but it seems kinda low to me.

Any ideas…any at all?

[brewtoo]

I'd love to see the answer to this.

We have a '90 and a '91. The '91 has ALWAYS had more "pep".

The '90 with the a/c off feels about the like the '91 with the a/c on, to give an idea of the difference...

I have a 1995 E420. Had it at my local Bosch authorized garage approx. 1 1/2 years ago for scheduled maintenance (approx. 85,000 miles on odometer then) and the master mechanic recommended flushing out the burn chambers. He explained that over the years and mileage, carbon deposits in the burn chambers and distorts the flow of air/fuel and lessens the intensity of the burn...thus, less power produced in each cylinder's burn chamber. I had been noticing over time that my car had become sluggish. Just didn't have the "get up and go" that it had when I bought it Starmarked with 36,000 miles. He had some sort of machine that flushed a chemical or solvent in the chambers. Car was like a rocket after that. This, of course, assumes that everything else has been maintained properly... timing properly set, good plugs and gapped properly, clean rotors, clean air filters, etc.

Perhaps someone on this forum can explain the burn chamber flush more technically. Good luck.

[brewtoo]

That must be the combustion chambers he's talking about.

Is there a way to really clean out the carbon buildup?

If so, how?

kogermeister, do you think it REALLY made a difference? Or was it maybe the placebo effect? Like when a freshly detailed car seems to drive better?

Thanks

The car really did go from being sluggish to acceleration and speed like when I first bought it. However, at the same time, I was getting a 30K service (also, rotors, oxygen sensor, etc.) which might have also improved the performance somewhat. My gut feeling is that the cleaning of the combustiion chambers did improve the power that the car had. Would like to have a Master Mechanic weigh in on the matter of the effects of cleaning out combustion chambers after the car has 80,000 or more miles on it.