Strange engine noise ... listen MP3 inside - Honda Prelude Forum

petrveit · 08-03-2003, 03:38 AM

My H22 engine in my 1995 4G with 60000 miles makes some strange noise, you can hear it here: http://www.volny.cz/veitel/prelude/vtec.mp3 .

The sound is comming somewhere from the timing belt area and it makes it only in the 1000-1100 RPM range, nowhere else. When the engine stays idle, the sound is normal (listen beginning of the MP3). When I just touch the gas pedal, so the RPMs goes to cca 1000, the strange sound starts. When I go higher (1100rpm or so), the sound disappears again. The sound is temperature independent (once I can reach 1000RPM when fast idle goes off, it makes this sound). It started after my timing belt change and engine rebuild (new rings and bearings). Exactly the same noise made my old F22 Prelude 4G, but it made it at idle and at 1800RPM. This sound from my old prelude ended after engine rebuild (new rings). With my new H22 it just started after the rebuild

.

I have tried the following:
- remove the PS pump, A/C and alternator belts, no change.
- change the auto tensioner to the manual H23 one, so the tensioner pulley is a new one. No change.
- remove the balancer belt, no change. So the balancer belt/shafts is not the problem.
- after disscussing this problem with Todd Marcucci (thank you!), I also tried to change the water pump with fresh coolant, no change.
- I tried to grease the pulleys that are on the crank shaft and also grease the pin, for the case that it would have some play. No change. Don't worry, the belts are not greased.

So even if I have only the timing belt connected to the engine (all other belts are disconnected), the sound is still there.

I found the only thing that can remove this sound: loosen the timing belt a bit. When I make it a little loose, the sound disappears, but my timing belt is vibrating at some speeds while it's running. Anyway, with the "right" tension (with a good autotensioner or with the manual one with tension set according to the Helms) it makes this terrible sound! The timing belt is not vibrating while it makes this sound.

So it seems to me that it depens ONLY on the tension of the timing belt, nothing else.

What can it be? I think I tried everything I could. Has anybody this sound too?

Did anybody of you see you timing belt while the engine is running? Does it vibrate on its way from the exhaust camshaft to the crankshaft (on its "longest" way) at some engine speeds? Or it is "straight" at all speeds?

racinghonda · 08-03-2003, 05:21 AM

Maybe its the timing belt? My 99 Civic used to make the same noise (brand new). The mechanic described the noise as cam belt wurr. You might just have gotten a noisier cam belt and it make the noise at a certain frequency and hence at those rpms only.

So maybe try a different cam belt?

MugenPoweredLude · 08-03-2003, 09:55 AM

to me it sounds like the cam gears are rubbing on the cover

petrveit · 08-04-2003, 06:20 AM

It makes this sound even if all the covers are removed. Also I don't think this is because the timing belt is new, because my old Prelude was doing this noise for 2 years

dilligaph · 08-04-2003, 08:22 AM

well you can find out if its coming from a particular area (specific cylinder, pulley, etc) by doin an old "listening" trick with a tool like a big flathead or a pry bar. put the handle against your ear and put the metal end on part of the engine. youll be surprised at how much internal noise you can hear from this method, its kind of like a stethoscope like a doctor uses to hear your heart beat.

here's a photodemonstration of my friend using this method.

petrveit · 08-04-2003, 01:21 PM

The tool is something like a common screwdriver?

dilligaph · 08-04-2003, 05:58 PM

yeah, anything like that will bring the sound up.. i know it sounds weird, but try it. see what your ps pump sounds like on teh inside, also if you put it on top of the valve cover, you can hear each cylinder at its respective position. its a great way to pinpoint a problem.

petrveit · 08-05-2003, 05:52 AM

I will try it. I am really courious what can this sound be....

vtecjustin · 08-05-2003, 06:22 AM

I drive a lude now but I had a civic that started making the same noise. I thought the sound was kind of wierd to and later the engine really messed up! For some reason I quit getting oil, yes it had oil in it, and I ended up replacing the motor. I am not telling you that is what the problem is but mine made that noise at first and then got worse. Good luck, If you find out, let me know. Thanks,
Justin

petrveit · 08-05-2003, 01:54 PM

Don't scare me

SuperSH · 08-06-2003, 01:46 AM

I noticed you diden't mention anything about changing the oil pump. Is it possible that the tension on the oil pump shaft is causing the sound. I would suggest another belt even an old one for diganostics. Is it possible that something is rubbing on the crank (or any rotating assy) behind the pullies like the main seal? Other than that maby a (the) main bearing(s) but thats just a shot in the dark.

vtecjustin · 08-06-2003, 05:10 AM

Didn't mean to scare you, but you really might want to check the oil pump.