Expert: Sean Halliday - 12/7/2007

Question
Hello Sean,
I just purchased a 2001 Honda Accord EX on Monday and it has a 1,000 mile / 1 Month Warranty included from the dealer.  Test drive sounded fine besides the "piston slap" at startup, and a clutch that has maybe 25% life left…

I didnt notice the "knockingish" type of sound until the car was real good and warm -- (it only does it after the car has been running for 20+ minutes).  It is faint, but certainly noticable and is only present sometimes like I said when warm.  It sounds like a kind of "knocking" and is present from 1800-2300 rpms only.  It seems to me that I notice it when maintaining a speed in gear (with just mild gas pressure).  A lot of people claim they can't even hear it actually cause its not real loud yet.. But I know its there..

I am very concerned that this could be a piston bearing that is worn or starting to wear… The warranty claims to cover "all engine lubricated parts" as well as a collaboration of other engine parts… But if I take it in there, they will have an easy time saying "yeah that is just gas" or "a timing issue" or "we can't really hear it"  - and I would have a tough time having them fix a bearing that is "starting to go" because the car is still very much drivable…

But if this is a bearing then it will certainly need an engine "prematurely".  My question is, do you think it is an engine (piston) bearing judging by the sound?  Or could it in fact be a timing too far advanced issue or a gas issue?  Or even something else?  It definitely sounds like a prominent "knock" rather than a click or ping.. I guess I just don’t know what detonation sounds there are besides the usual "ping" that I've hear when accelerating hard or going up hill on other cars.  

If it is a bearing, what are my chances of having them pay for it / fix it?  

Any advice would be greatly appreciated!

Answer
Seems that if they gave you a warranty,they must honor it and if youre not happy with the sound,they must fix it.You didnt say how many miles are on it but a 2001 should have about 80k so unless its in the 100s ,then its possible a main bearing or big end bearing is worn.This is unusual for a Honda as the engines are practically indestructible.The piston slap isnt normal either or is the 25% on the clutch so it would appear that you will need to fit a clutch soon.Pinging occurs when the timing is off even slightly but this is quite a different noise from a bearing and as you describe that by holding the gas at 2300 rpm,thats what will occur.It wont be noticeable at all rpm.I would go back and if they are anyway decent mechanics,they will know a run bearing when they hear it.It may be a Honda,but i have known people to drive with no oil or low oil so its possible you may have bought a car which has had no maintenance or has been"rallied"......so you dont know what type of person has driven it.It is easy to destroy an engine in a short time.