2005 E320 CDI: throttle, diff, rear suspension questions
Thread Starter
Newbie
Joined: May 2017
Posts: 11
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2004 E320 CDI
2005 E320 CDI: throttle, diff, rear suspension questions
Hi all. My first post here as I purchased an '05 E320 CDI in December. 200k miles but impeccable service records and many new parts so I'm pretty confident I've got a winner (zero black death too 😁
. I've got three problems left I am trying to solve. None of these existed when I bought the car, so it's all up to me.
Thanks –
Micah
. I've got three problems left I am trying to solve. None of these existed when I bought the car, so it's all up to me.- The throttle gets very wobbly when the car is cold. When you have very gentle throttle pressure, i.e. driving at 40 MPH. This speed is normally about 1200 RPM in my car, but when it's acting up, the RPMs fluctuate, bouncing back and forth between 1000 and 1400 RPM. One second cycle, i.e. 1400 -> 1000 -> 1400 takes a second. This disappears when the car is warm.
- Maybe related, maybe not, but I have diff noise. This is loudest when cold and only diminishes slightly when warm. This occurs when you let off the throttle or gently accelerate. A tap of the brakes usually quiets it down when you're not on the throttle. I changed the diff fluid last weekend. It was a little dark and I swept a magnet through it and picked up no metal shavings, nor did I see any in the fluid. The noise is like an exhaust note but real drone-y and higher-pitched. (It's not exhaust, that's all checked and is in excellent condition.)
- The rear end is real squirrelly over bumps, namely when only one side of the car hits a bump or pothole. Say the passenger side hits a bump (like the many poorly-recessed storm drains near my house). When the back end hits the bump, the car lurches toward/into the bump and then bounces back out in the opposite direction. In other words, a bump on the right side makes the back end lurch to the right, then to left, then back to normal. I also replaced the shocks last weekend with the OEMs from FCPEuro: the ones that were on there were shot, but the bouncing is maybe only slightly improved now. The car has had some aftermarket mods, but they're not really "performance" mods (just the basic rocketchip tune), so I don't think the springs in back are some performance things. I have replaced the shocks.
Thanks –
Micah
Last edited by laerm; Feb 19, 2020 at 11:26 AM. Reason: updated
Junior Member
Joined: May 2016
Posts: 36
Likes: 4
From: New England
2006 E320 CDI
I'm glad you solver the transmission problem, if i saw this sooner I would have recommended that you also change out the solenoids. 100$ on amazon. (My torque converter lockout solenoid went recently @240k Miles)
The rear shimmy you are experiencing over bumps is likely the rear springs and shocks. I had the same thing and changing those out fixed it. Also it fixed the uneven rear tire wear (worn on the inside treads) It's an ok DYI as long as you have the correct spring compression tool.
Are you sure the noise comes from the diff? Could it be rear brakes or e brakes?
The rear shimmy you are experiencing over bumps is likely the rear springs and shocks. I had the same thing and changing those out fixed it. Also it fixed the uneven rear tire wear (worn on the inside treads) It's an ok DYI as long as you have the correct spring compression tool.
Are you sure the noise comes from the diff? Could it be rear brakes or e brakes?
Thread Starter
Newbie
Joined: May 2017
Posts: 11
Likes: 0
2004 E320 CDI
Hi. So, I dunno what you mean about the transmission, I haven't had any transmission problems...
I did replace the shocks, looks like I forgot to mention that, sorry.
I'm 90% certain it's the diff. I haven't messed with the e-brake yet, but I did inspect the rear brakes when I changed the shocks and they seemed fine. Thoughts on what to look at for the e-brake?
Thanks!
I did replace the shocks, looks like I forgot to mention that, sorry.
I'm 90% certain it's the diff. I haven't messed with the e-brake yet, but I did inspect the rear brakes when I changed the shocks and they seemed fine. Thoughts on what to look at for the e-brake?
Thanks!
Junior Member
Joined: May 2016
Posts: 36
Likes: 4
From: New England
2006 E320 CDI
Hi. So, I dunno what you mean about the transmission, I haven't had any transmission problems...
I did replace the shocks, looks like I forgot to mention that, sorry.
I'm 90% certain it's the diff. I haven't messed with the e-brake yet, but I did inspect the rear brakes when I changed the shocks and they seemed fine. Thoughts on what to look at for the e-brake?
Thanks!
I did replace the shocks, looks like I forgot to mention that, sorry.
I'm 90% certain it's the diff. I haven't messed with the e-brake yet, but I did inspect the rear brakes when I changed the shocks and they seemed fine. Thoughts on what to look at for the e-brake?
Thanks!
You said you replaced the shocks n the back, what about the springs? Mine pretty seriously soft by 200k. New ones made a bid difference in ride stability.
Not a bad idea to look at the sway bar... Also there are some big bushings that hold the whole rear subframe, make sure those are in good condition.
