Ok, so I can only make some educated guesses about what it might be since engines aren't my specialty, so I thought I'd post to get the 'real deal' asfar aswhat is most likely causingthe 'growling'. It's my gf's car, so I don't hop in it often, but for the mostpart issounds a little rough. It sounds really rough while under acceleration, andby that I mean that is when it seems to have the 'growl' sounds the most. It's all stock, 189k,no rebuild,original tranny, etc. A couple times the oil has been real low, and she is very bad about starting it in the morning(and other times) and then just driving off immediately. Is this worn rings? Any help is most definitely appreciated :-)

 

not to be a smart a$$, but a growling sound under acceleration sounds very desirable. Perhaps you can describe the sound a little further?

 

give us car specs.. year, engine type, etc....

cleaning up the intake manifold (or even just the butterfly valve) can improve sound and performance quite a bit..

http://i219.photobucket.com/albums/c...s/Engine01.jpg

Where my CAI hooks up (the red tube) is the intake valve.

- Steps to clean -

1) Remove intake by unclamping and pulling aside... It doesn't have to be 100% completely off, just enough to spray and possibly scrape inside...
2) Spray some carb cleaner inside the valve, and let it sit for a couple minutes... 5 at most is needed, but 10 doesn't hurt (since I clean mine every oil change I let mine sit maybe 2-3 minutes).
3) You can use this step to also LIGHTLY scrub the inside with an old toothbrush or a BRASS wire brush... You don't want to damage the porting here or your valve won't get a good seal.
4) Crank engine
5) While revving the engine, spray more carb cleaner into the valve... The engine will want to die, so you'll have to have some control over the accelerator/throttle body at the same time. Do this about 2-3 times.

If this doesn't fix it, then clearly it's not that... but this is a generally easy and well-received maintenance tip (aka, it usually fixes SOMETHING)

 

lol....how about maybe a 'grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr rrrrrrrrrrrrrrrrrrrrrrrrrrrrrr' sound? It just has a more gravely sounding idle, which is even more amplified under acceleration. I'm not inclined to think it is too tranny related since it can still be in park and be sounding this way while in idle. Maybe 'smooth sounding' isa phrase you could definitely NOT use when describing this engine?

 

For the specs I know of, and I don't know Honda well, it's a 99 Accord with auto, 2 door, 4 cylinder, and basic trim level. Does that give anyone enough to go off?

I'm familiar with carb cleaning procedure since I did it with a Pathfinder I used to have, but only for cleaning off gunk from the butterfly valve. I'm curious how this might affect the sound and performance...does it makes its way down to clean the valves, etc.?

 

I think its based on the idea that sounds can do really funny things in a car. What you hear in the drivers seat might be WAY different than if you were sitting in the engine bay.

But you can also check the engine mounts (4 of em). If the rubber part falls apart theres usually metal-to-metal contact that prevents the engine from coming completely unglued.

Also related to engine mounts... If the engine moves too much, the exhaust pipe can flex around & hit the floorpan.

 

Well it definitely isn't the exhaust hitting the floorpan. The motor mount idea is interesting, but I'd be more inclined to think it might need a valve job or something. Would something like this possiblybedescribed as 'valve chatter'?

She has also been getting horrible mileage...no numbers to go on, sorry guys, just what she says, and I don't know how bad...but if she has noticed, it probably really is happening. It's probably an unrelated problem like...fuel filter? I don't know.

 

Valve clatter is a clicking sound mostly under the hood. Usually just as loud when idling. In fact idling is where you normally notice it.

Leaky exhaust manifold gasket? The exhaust pulses are so sharp up there that it usually sounds much different than an exhaust leak back in the piping.

 

Hmmm, thanks. It definitely isn't valve clatter then.

It isn't the exhaust manifold or gasket either. I've had thata couple times before, and that noise is one I know well. What about some type of oil sludge? It is only about 2500 miles in, but she drives it pretty short distances. Another way that might make the sound more identifiable, is to think about how the engine sounds quieter after an oil change. It would be the 'before' sound, when it is a bit louder, but this is much louder than I would say is 'normal'.

 

Well you can check for sludge by pulling the valve cover & looking around. If you suspect that, drain the oil & use a coathanger or some kind of plastic stick & scrape around the bottom of the oil pan. See if youcan find any solid chunks.