Just got the timing belt/water pump replacement done on my daughter's '02 Accord 4 cyl about a week and a half ago at a local Honda dealership. I was in her car yesterday, and noticed a vibration at idle that wasn't there before the work was done. I called the dealership and will be taking it back this Thursday. I'm sure they are going to say it had nothing to do with the work they did.

Any ideas on what could be causing the vibration?

 

It "could" be possible that they havent aligned the balance shaft on the engine correctly. (may have had an apprentice do the job)
Has the CEL (check engine light) come on the dash at all and stayed on during normal use?
Also is the vibration only at idle or does it change as the rpm's alter?

 

this is my question as well.

 

Could be as simple as forgetting to tighten a motor mount.

 

I hadn't thought of the motor mount, but I have seen the effects of the crank pulley bolt not being tightened properly / crossthreaded
(end result = bottom end of engine destruction)

 

No, we haven't had the CEL come on.

I didn't drive it around to see if the vibration got worse as it drove. I might try that tomorrow night. The vibration seemed constant at idle, not too bad, but I did definitely notice it.

I was thinking it might have something to do with the motor mount, but I wasn't sure if they would have to either loosen the motor mount, or unbolt it altogether to change the timing belt?

 

The mount on the front of the engine has to come off to do the timing belt, so that could be the problem. Also a fowled spark plug could cause a slight missfire at idle causing a very minor vibration..... be wary that if it is something simple that they have done to cause the issue, they may make up an excuse to charge your daughter for repairing their fault. If possible take the car there yourself or go along with her, some places like to try pull the wool over the eyes of females - generally not the case with a Honda dealership, but you just never know.

 

Haha, that would certainly be on the more serious end of things.


OP you can look in the Accord FAQ for the timing belt procedure and get an idea of what all is involved.

 

I'll be the one taking the car to the dealership. I wanted to see what kind of responses I got from everyone here, so I can have some things to keep in the back of my mind while they try to pass the blame off on something not related to the timing belt work they did.

I was also thinking maybe it was spark plug related, but would replacing the timing belt cause a problem to arise with one of the plugs, or exacerbate a problem that did exist before the work? While I don't normally drive the car around, I changed the oil a couple of weeks before the timing belt work, and didn't notice the vibration then.

 

When the dealership replaced the timing belt in my car, they somehow managed to knock free some carbon in the EGR chamber causing it to missfire and vibrate / idle funny.
Thing that I noticed most was they had slotted the distributor to full advance just to get the car running again, also I think they had the timing belt out a tooth or so.
(guessing this as there wouldn't really be any need for the distributor to be fully advanced) end result was they knew I had some knowledge in engines and repaired it all at their cost with no extra charges.

 

Balance belt not aligned properly to the marks is the most likely cause. Misaligned balance belt vibration disappears as the rpm climbs.

BTW, you aways replace the balance belt when the timing belt is done -- it's simple preventative maintenance, and it would be crazy to take the car apart and not do while you were "in there" replacing the timing belt. So if they claim not to have touched the balance belt (or similar BS) you have every right to say: Why not?

 

Sometimes techs dont reinstall the front motor mount stopper correctly. Look at the timing cover engine mount. The stopper is fastened with a 12mm nut. There is a tab on the stopper that should touch the mount bracket. This may be the problem.

 

If it makes a thumping sound when you start it or shut it off, it's likely to be the mount.

If it hesitates at all in the lower RPMs, it's likely to be the timing belt.

If it vibrates all the time and gets worse in higher RPMs, it's likely to be the balance shaft belt.

 

I haven't driven it to see if the vibration gets worse, but I talked to my daughter, and she said that it doesn't seem to be worse when she's driving around.

Thanks to all those who replied. I will follow up tomorrow after I go to the dealership, to let you know what they say.

 

What did the stealership say?

 

The stealership? Bad technicians are everywhere, not just at dealerships.

 

if they changed the water pump it might be as simple as air being in the coolant. try bleeding it, its easy and doesnt hurt to try.