2k 'Lude intermittent rattling noise from water pump area

Hi,
This is for the SportsShift transmission non-SH model.

1. Noise is there with transmission in D or N
and car moving or idling.
2. Noise is a low frequency "cluck, cluck, cluck.."
type like if you beat a chopstick inside a plastic
cup (sorta like the freezing/rusting distributor
problem found in so many Hondas execpt this one
is probably not the distributor).
3. Noise is most noticible when RPM is droping
to the idle speed like if you press and release
the gas pedel quickly and at around the
moment that the RPM reaches the idling speed,
it "cluck, cluck, cluck, cluck,..."
4. Lately it intermittently clucks a minute at a
time.

Possible cause
1. I noticed the problem after a raditor coolant
change. I think the dealer did a radiator back-flush
which I think was not recommended by the service
manual.
2. If I drive over something bumpy real fast, I can
hear metallic clucking sounds coming from the
engine area.

Does this sound like a water pump problem? Or can a loose
metal cover of some kind cluck out that kind of rhythm noise?
But can this noise be a water pump noise at all?

Thanks

 

It doesn't sound like my experience of a water pump which has a bearing
starting to go bad - I had a chirping sound when cold and a high pitched
whistle when hot. I guess it's possible that if the shop who did the
coolant change accidentaly flushed a "foreign body" into the system, it
could be rattling around - I don't see what else.

I'd be more concerned that it might be something to do with the timing belt
or gear - possibly a bad tensioner; apparently the Prelude has a special
(hydrauulic?) tensioner not seen in other models. Has the tension been
adjusted recently? Whatever it is, you or a mechanic has to get in there
to investigate *soon* - you don't want the risk of the timing belt
breaking.

Are you sure it's not just one of the accessory belts, A/C, Alternator or
P/S, which has a bad spot on it?

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??

 

I'm pretty sure it's not the accessory belts because I can
sorta hear that it sounded like it's coming from inside the
engine on the water pump side. Sounded like some object
knock against a plastic shell. It doesn't happen all the time.
It only happens when the engine is warmed up and even then it
happens mostly when the engine is changing speed at peak or
bottom RPM like if you press the gas pedal and then at the
point when you release it, the sound happens for a few seconds
and then also when the RPM hits the bottom and it would clunck
for a few seconds and then goes away.

Andy

 

it's timing belt flap, not sure if it covers yours but there was a
bulletin on this, the tensioners went bad.
Chip

 

Can I find this bulletin on the web?

Thanks

 

Check here http://www-odi.nhtsa.dot.gov/cars/problems/tsb/tsbsearch.cfm
where you'll likely only get a summary - Honda withdrew the full TSBs from
general publication - but at least you'll get the TSB #. You can try
replacing the 627312 in this URL http://www.nhtsa.com/TSBScans/sb627312.pdf
with the TSB you get. There are a few available - not sure why but maybe
just safety related things.

Rgds, George Macdonald

"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??