strange new noise.
 

just noticed a strange noise this weekend, coming from engine. up with the hood, and i cant place where its coming from. the engine has been very quiet for as long as i have owned this car, so i'm wondering. it does follow engine speed, but its not regular? i have to say it sounds like its coming from the exact middle of the engine, like something is loose. having said all of that, i have owned the car since late 2000, and all belt maintenance kept up to date. i have always checked the rollers, and they were ok at last tension, however, the more i think about it, it could be the bearings/water pump. any thoughts?
still the same rollers since 2000, and water pump has about 30000 miles on it.
guess its back up onto the ramps tomorrow for further investigation.

Have you got a stethoscope?

Water pump will sound like the top of the engine is comming off. Take off the top belt cover and wiggle the water pump pulley. They don't always leak first.

no stethoscope here, i have tried using the end of a long screwdriver, against the engine, but all i hear is the orchestra, i cant pick out the trumpet player!! well, i guess it sounds like a bearing, and it does actually sound like the engine is going to grenade, so the cover is coming off tomorrow, and i will check all rollers, and especially the water pump bearing/ shaft.
thanks for the info guys.
bob.

Check the timing belt tracking on the cam pulley. The cam pulley's center bolt can come loose. Might see if you can wiggle it also.

Yeah - and when that happens the car sounds like a tractor at idle, what with the rotor hitting the cap as it goes around.

what type of sound is it? a knocking, clanking, whining?

grab yourself 3' of vinyl tubing. stick one end in your ear, and move the other end around until you find the sound... that's how i found a vacuum leak on my car..

ha ha, good one kyle ! my neighbours already think i'm deranged, so that would be in character !
well, stripped it all down, and the balance belt idler roller, is rough/noisy. i tried to move the water pump bearing, and to be honest, using a lot of pressure, i feel what i think is about 0.005" play. its very minimal. also, lots of belt dust in there, more than any other time, and it seems like the belts are slack . could this be belt slop ?
as to the noise, i can only say it sounds like a "grating" kind of noise. its not regular, in time with the engine, it comes and goes/different volume of noise/pitch. as i increase the revs, it does go up, but again, its not constant, in time with the engine.
if i did not know any different, i'd say something has come loose internally !
i'm going to hook up the afm, and start the car, and see if i can detect anything from the belt area/water pump, now its all open.
also will check the timing belt cam etc. thanks guys.

There shouldn't be play in the water pump bearing. Does it feel notchy when you spin it? The belt dust may be a clue, but I get that too and it doesn't mean anything. Maybe alternator bearings (I have some experience with this...).

Kyle, love your idea! I introduced our 7-year-old to the stethoscope the other day. It was worth it for the look of astonishment he got when I touched it to the cam housing. "Do I sound like that when I go to the doctor, Dad?"

"Only under a full moon, Son..."

LOL Simon, you are too funny. A young mind is a terrible thing not to mess with...I mean waste.

well, i ran the engine with the covers removed, and it does seem like the noise is coming from the water pump. it sounds most noisy right above this area, so unless its something to do with the balance shafts, its time to start stripping it all away and replace the pump etc etc.
being on afternoons gives me little time, but i will check the water pump bearing tomorrow, after i remove the belts, and can get a true feel for it, with no tension.
one last question. what is the recommended sealant to use with the waterpump gasket ?
bob.