VS surging back and forth.

[someguy360]

Hi Guys.

Odd problem with my VS.

Over the past few weeks when cruising at 60-65 the car feels like its shuddering backwards and forwards.

I can feel it through the pedals and I can also visibly see my keys and gear shifter wobbling backwards and forwards when the problem occurs.


I have installed a brand new set of wheels and had them properly balanced and alligned so im not sure thats the problem but the symptoms did occur not long after the new wheels were fitted.

I also thought it could have been my faulty transmission that had been slipping and carrying on over the past month but I dropped a new one in over the weekend and that hasn't solved the issue either.


I know my struts and shocks aren't great (original shocks/struts on SL Springs so pretty stiff but I have had that setup for around 2 months prior to these symptoms popping up)


Just can't seem to find what the cause of the problem is.......it almost feels like when the problem happens its the engine missing ever so slightly...not enough to throw any codes or cause any major issues but just enough to be noticeable while driving. (also I can't hear any drops in revs or any uneven-ness in revs when the problem occurs)


Has anyone ever had anything like this before...its got me stumped.


Car in question is a Live Axle sedan.

Regards

[elmaso]

have you had the engine mounts replaced? could be a contributor.

[someguy360]

have you had the engine mounts replaced? could be a contributor.

I haven't replaced the engine mounts but I did inspect them when I was under the car the other day....they don't look too bad...not sagging...yet

[IBLOWN]

Depends on what you mean by surging. How fast does it surge? i.e How many times a second? It could be anything otherwise.

[someguy360]

Depends on what you mean by surging. How fast does it surge? i.e How many times a second? It could be anything otherwise.

Well it feels like the car is mildly shuddering.

It happens around 2-3 times per second.


To understand the feeling thats going on, think of braking with warped rotors, the cars shudders/pulses when slowing down....it feels similar to that but under light throttle usually between 60-70km/h

[elmaso]

injectors or fuel system? its something that pops to mind when you think of jerking/shuddering.

[someguy360]

injectors or fuel system? its something that pops to mind when you think of jerking/shuddering.

Could be, might get the fuel system's presure etc checked while its getting some leaks fixed tomorrow.

It doesn't seem down on power but I guess that doesn't rule fuel out

[elmaso]

i was thinking dirty/clogged injectors could have that kind of effect on it, but im just trying to help you brain storm with this lol