Annoying rattle was stabilizer bar links

[djc]

C-max (built end of  July 2013) had annoying low-speed rattle.  Especially prominent over minor-bumps at speeds under 30.  I took it in for service last Friday.  I assumed it was the jounce bumpers, since that is what gets greased up in accord with the TSB 13-12-9 for this symptom.

However they diagnosed the noise using "chassis ears" and determined the front stabilizer links were worn and were the cause.  Dealer replaced both front links and bolts. 

 

They also repaired the factory installed engine block heater, which had stopped working earlier this year.   Dealer confirmed and fixed by reseating plug at heater.  When I asked about how to do this if it recurred, I was told the car needed to be on a lift because access was only from below, reaching up in tight space between rear of engine and firewall - and only when engine was cool.

 

I also mentioned a third concern: a large jerk when nears full stop while doing down a steep hill if "grade assist" has been used.  This is potentially dangerous as it could cause the car to lose traction on a wet, snowy, or icy road and careen out into an intersection.  The dealer could do nothing as it is presumably a design / programming problem.  Dealer recorded concern and sent on.

 

In any case, two problems fixed before original warranty expires.  I bought the car April 2015 with 27k miles; it has about 34k now.  I like it a lot -- more so without continuous rattle.

 

 

 

[fbov]

.... I also mentioned a third concern: a large jerk when nears full stop ...

Is the jerk you feel a pull, like the car speeds up? I think it's really the car slowing down less, which feels the same. I've noticed it in traffic, when slowing for a turn, the car would leap forward a little as I started to turn in. 

 

I'm now thinking this may be due to prolonged high braking scores; I trained myself to get ~95% regen, so the friction brakes aren't seeing much friction. Visual inspection shows the rotors have rusted a little, and as a result, there's less surface area contacting the brake pad, so less braking force. I've started braking hard from speed occasionally, in an attempt to level the rotors a bit.  

 

We'll see,

Frank, who just changed his oil.

[C-MaxSea]

I agree Frank.  We have experienced the same slowing for a turn brake jerk (pad slip & catch) a couple times coming off the freeway at one specific location.  At around 97 percent recovery on our brake score, I too think it is the lack of friction brake use and am trying to find good opportunities to invoke the pads now and then without an oncoming turn, just to give the pads and rotors some work & leveling.

 

Nick

Edited June 13, 2016 by C-MaxSea

[djc]

Curing the front suspension rattle last Friday revealed a similar rear rattle.  The rear rattle is not as pronounced as the now-cured front rattle.  Again, it is low speed and occurs over minor bumps.  I will likely re-visit dealer before factory warranty expires. It could be the bumpers at the top of the rear shocks - I slid the driver's side one down by reaching over the top of the rear tire (tight fit for hand).  There is a TSB for the front ones making a rattle.  The rear sway bar links are easy to see / reach from the rear of the car - look and feel fine.

 

BRAKES:  I have not experienced this jerk when slowing on level ground, whether for a turn or a straight stop.  It is only down a steep hill.  It is in the last few mph as it comes to a stop.  It feels like the brakes are released then suddenly applied again, producing a jerk.  That can cause loss of traction on at a stop on a hill, and the car could slide out into the intersection.  I am hoping for an eventual update to the module that controls braking  (and not as a result of a lawsuit filed by my heirs).