I posted a week or two ago about a problem I was having with a CEL and a starting issue on my 1999 Accord 2.3L LX sedan. I got the startup problem solved by having the ignition switch replaced for free as it was a recall repair that was never done, and the CEL ended up being a broken EGR valve which I also had repaired. Everything seems fine, but I also recently had my water pump and timing belt replaced, and ever since then I've noticed a strange vibration coming from the front of the car. When I start the car, I can feel it as a quick shuddering in the wheel, and I can also feel it as I'm braking to a stop below maybe 10 mph, and it goes away if I pop the car into neutral while slowing. It definitely is related to the belts/water pump, as it happened the first time I started the car after the repair and never before then. My question is- When replacing the water pump and the belts, what could cause an unusual shudder or vibration? Is it something to do with the engine mount or the belts themselves? I'm not really bothered by it, but if it's something that will rear its ugly head later in a far more expensive way I'd like the mechanic to fix it ASAP.

 

The belt for the balance shafts could have been installed off by a tooth.

I would also look for cracked rubber in the motor/transmission mounts.