# After A/C replaced: Thunk crank-over+moving-accelerate-tap; Flapping fluttering stopped-foot-brake **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** airconditioning, brakes\ **Created:** [July 17, 2007, 9:31pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867 "2007-07-17T21:31:46Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Grace\_Guer](https://avatars.discourse-cdn.com/v4/letter/g/e99b99/32.png) [@Grace\_Guer](https://community.cartalk.com/u/Grace_Guer)\ **Post date:** [July 17, 2007, 9:31pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/1 "2007-07-17T21:31:46Z")
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 ---
**Author:** ![Craig58](https://avatars.discourse-cdn.com/v4/letter/c/3da27b/32.png) [@Craig58](https://community.cartalk.com/u/Craig58)\ **Post date:** [July 17, 2007, 9:36pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/2 "2007-07-17T21:36:57Z")
I would bring it back and have them drive it. Maybe a problem with the belt or tensioner installation? Maybe they left something loose? ---
**Author:** ![star882](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/star882/32/39_2.png) [@star882](https://community.cartalk.com/u/star882)\ **Post date:** [July 18, 2007, 1:01am UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/3 "2007-07-18T01:01:29Z")
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. ---
**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\ **Post date:** [July 18, 2007, 2:10pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/4 "2007-07-18T14:10:37Z")
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? ---
**Author:** ![Grace\_Guer](https://avatars.discourse-cdn.com/v4/letter/g/e99b99/32.png) [@Grace\_Guer](https://community.cartalk.com/u/Grace_Guer)\ **Post date:** [July 18, 2007, 2:14pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/5 "2007-07-18T14:14:06Z")
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? ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [July 18, 2007, 2:15pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/6 "2007-07-18T14:15:49Z")
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. ---
**Author:** ![Craig58](https://avatars.discourse-cdn.com/v4/letter/c/3da27b/32.png) [@Craig58](https://community.cartalk.com/u/Craig58)\ **Post date:** [July 18, 2007, 3:24pm UTC](https://community.cartalk.com/t/after-a-c-replaced-thunk-crank-over-moving-accelerate-tap-flapping-fluttering-stopped-foot-brake/1867/7 "2007-07-18T15:24:22Z")
It sounds like he just left something loose, it should be OK as long as the belt wasn’t damaged.