After A/C replaced: Thunk crank-over+moving-accelerate-tap; Flapping fluttering stopped-foot-brake

brakes
airconditioning

#1

Q/ What can possibly be (unintentionally) mis-adjusted in a CRV while replacing the A/C? AFTER replacement of A/C unit, the car feels like something is not slipping into position properly.



2002 CRV-EX/automatic/104K HWY miles/One owner/serviced as scheduled.

? We were going about 40mph: Turned A/C On, got a growl-grind noise PLUS cool air output. Turned A/C off, fan was still blowing OK.

? Dealer said: replace A/C, it?s dying.



Now, AFTER replacement of A/C unit:

1) The car feels like something is skipping or slipping when it engages the transmission.

2) It Thunks once when ignition turned-over: cranked over >> thunk; Off >> thunk

3) Now accelerate lightly, FOOT OFF then ON the accelerator, it produces Thurnckp noise, It repeated when tapping for 2 blocks, then I stopped testing.

4) Let roll forward, lightly break ->-> Thurnckp dull sond.

5) While resting at stop light or inching forward PLUS foot on the break (lightly) ->-> Rapid flapping/fluttering Tbrrp, Tbrrp, Tbrrp, Tbrrp, noise (akin to card against bike spokes ?short burst). Flapping frequency decreases if foot is off-then-on the break several times (3-5X).

6) Hm,??.something is hitting, like the fan on the shroud; ??then the thunking and plunking; ??and the raspberry blowing. It -could be funny, if so scary it wasn?t.



[In addition, they also performed an SRS diagnostics because the light was on (SRS light had come on after battery went dead (parked, radio on) ? dealer didn?t know at the time). ^^^^^DIAGNOSIS: ?It?s Bad?–should replace. However technician did not know about the battery dying, and they did not reset the SRS as I opted to think about it.]



Hey Thanks for any comments!



Grace




#2

I would bring it back and have them drive it. Maybe a problem with the belt or tensioner installation? Maybe they left something loose?


#3

It can be anything that was moved during the repair.

If it still happens with the A/C off, it’s most likely not anything with the A/C.


#4

Craig, thanks! You are on target.

RESULT from Honda Tech that replaced the A/C:
I took the CRV back and the Tech cranked it on-off, listened to the thunks and said ?I know what this is, let me take it to the shop?. He was back in 15 min and we went for a test drive. The thunking, plunking, brake flapping/raspberry blowing were all gone. He explained something about cradle mount & bushings & sitting askew & collar and rubber gasket & nuts at the engine bracket & tighten nut that he had missed.

Regarding the SRS, he did reset the SRS manually and advised me to have the battery checked (it is 5 years old), replaced if required, then they will reset SRS and we are to monitor the light.

Thanks for great quick advise! Should I be in the look out for deleterious effects?


#5

Craig58, thanks! You are on target.

RESULT from Honda Tech that replaced the A/C:
I took the CRV back and the Tech cranked it on-off, listened to the thunks and said ?I know what this is, let me take it to the shop?. He was back in 15 min and we went for a test drive. The thunking, plunking, brake flapping/raspberry blowing were all gone. He explained something about cradle mount & bushings & sitting askew & collar and rubber gasket & nuts at the engine bracket & tighten nut that he had missed.

Regarding the ERS, he did reset the SRS manually and advised me to have the battery checked (it is 5 years old), replaced if required, then they will reset SRS and we are to monitor the light.

Thanks for great quick advise! Should I be in the look out for deleterious effects?


#6

Sounds to me like they forgot to tighten a motor mount, and when they tightened it everything (the engine) stopped shifting around. It should be OK now.

If the SRS light stays off, I would not worry about it. If it comes on and stays on, the airbag system is disabled and will NOT function in a crash. Whether you choose to spend the money to fix the airbag is up to you.


#7

It sounds like he just left something loose, it should be OK as long as the belt wasn’t damaged.