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?