Jump to content
CaddyInfo Cadillac Forum

Intermittent Movement of Rear Suspension


MAC

Recommended Posts

I've noticed on a few occassions when stationary that the back of my recently purchased '94 Eldorado will move as though I've been slighlty bumped/tapped on the rear bumper. One day I was at a taffic light and I thought the car behind me tapped my rear bumper. It made me look in my rear-view mirror. What could be causing this problem?

Link to comment
Share on other sites


Do you think its coming from the tranny?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

Do you think its coming from the tranny?

No, not at this point. I was in park talking to a friend and all of a sudden the back end moved like the bumper was tapped. I've only noticed it when the car is standing. I'm thinking it may be an air shock relief valve suddenly releasing air?

Link to comment
Share on other sites

Now THAT'S weird! The only times I had that happen to me were: 1) During an earthquake. 2) When the fuel in the tank sloshed forward. 3) When the "fuel" in MY tank sloshed forward. :lol:

Never underestimate the amount of a persons greed.

Link to comment
Share on other sites

When my buddy's Torque converter went out on his F350 the initial sypmtoms were a slamming sensation coming from the rear. He mentioned that at first he swore someone had hit him from behind, while stopped at a traffic light. I know it's a RWD truck, alot different than a FWD Caddy, but thought I might through it out there ;)

A.J.

Link to comment
Share on other sites

When my buddy's Torque converter went out on his F350 the initial sypmtoms were a slamming sensation coming from the rear. He mentioned that at first he swore someone had hit him from behind, while stopped at a traffic light. I know it's a RWD truck, alot different than a FWD Caddy, but thought I might through it out there ;)

I was thinking it was something like that or a sprag, that is why my 91 used to do, now I know its a different tranny but the concept is the same. However, when it jumped forward it made a metallic noise by the tranny.

I don't think there is anything in the rear that could cause you to bump forward like that. Unless you have a bad cross axis ball joint in the knuckle and it shifts after you stop. The suspension kind of settles as the suspension relaxes it shift to a neutral position after it recovers from the braking stresses that twist the knuckle. Just a thought. I will have some photos of my knuckle if I pick up one in the scrap yard this weekend.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

When my buddy's Torque converter went out on his F350 the initial sypmtoms were a slamming sensation coming from the rear. He mentioned that at first he swore someone had hit him from behind, while stopped at a traffic light. I know it's a RWD truck, alot different than a FWD Caddy, but thought I might through it out there ;)

I was thinking it was something like that or a sprag, that is why my 91 used to do, now I know its a different tranny but the concept is the same. However, when it jumped forward it made a metallic noise by the tranny.

I don't think there is anything in the rear that could cause you to bump forward like that. Unless you have a bad cross axis ball joint in the knuckle and it shifts after you stop. The suspension kind of settles as the suspension relaxes it shift to a neutral position after it recovers from the braking stresses that twist the knuckle. Just a thought. I will have some photos of my knuckle if I pick up one in the scrap yard this weekend.

The rear end moves up and down slightly like the bumper's been tapped but the car doesn't attempt to move forward and I don't hear any metalic sound. I know it sounds strange but I'm not the only one who noticed it. The last time it happend I was in Park and my friend is the one who noticed movement and brought it to my attention.

Link to comment
Share on other sites

If you do a little search, the knuckle will creak and squeak as it settles, my guess is that yours is settling. On braking, the knuckle can twist, its possible you are feeling it settle back down

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

Link to comment
Share on other sites

I would disconnect the rear struts from the CCR (or wharever it is called) and see what happens. The rear may sug though... Are you sure the mother-in-low is not in the trunk? :)

The saddest thing in life is wasted talent

Link to comment
Share on other sites

I would disconnect the rear struts from the CCR (or wharever it is called) and see what happens. The rear may sug though... Are you sure the mother-in-low is not in the trunk? :)

Maybe I will disconnect the struts and see what happens if the problem persists. It's certainly not the mother-in-law since I'm not married. B)

Link to comment
Share on other sites

I would disconnect the rear struts from the CCR (or wharever it is called) and see what happens. The rear may sug though... Are you sure the mother-in-low is not in the trunk? :)

Maybe I will disconnect the struts and see what happens if the problem persists. It's certainly not the mother-in-law since I'm not married. B)

That's good. Diagnosing an autoamtic suspension is much easier than diagnosing a mother-in-low. Leave alone disabling. :lol:

The saddest thing in life is wasted talent

Link to comment
Share on other sites

Here are the only codes I'm getting, all related to suspension:

S011 Left Front Damper Solenoid Valve Short to Ground/Open

S013 LF Damper Solenoid Short Across Load

S018 Right Front Damper Solenoid Short Across Load

S021 Left Rear Damper Solenoid Valve Short to Ground/Open

S023 Left Rear Damper solenoid Short Across Load

S026 Right Rear Damper Solenoid Valve Short to Ground/Open

S028 Right Rear Damper Solenoid Short Across Load

S036 Electronic Level Control Compressor Short to Ground/Open

S044 Lift or Dive Signal Fault

All these codes are 'HISTORY'. Every time I check codes I never see any of them as 'CURRENT'. However, I can't clear them despite they are saved as HISTORY and it's been more than 50 starts and they still have not cleared. Would anyone know if these codes as a whole mean anything particular, perhaps the previous owner installed passive shocks or maybe a fuse is blown?

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...