hidom

I just recently bought this LS400 99' with 121k miles on Craigslist.

Not sure where the noise is coming from but I can hear it every time I start up the car. It sounds like it's coming from the area of the timing belt and the fan. Anyone know what exactly is it? The noise itself sounds like a low bass.

Everything else works fine. Full stock, no mods...yet. I was thinking of just bringing it to the dealership and run a diag on it to figure out the problems within my car. Any suggestions? I was wondering if it will also, damage my wallet drastically if I don't get it fixed right away.

PureDrifter

iTrader: (10)

if the timing belt hasnt been done the belt could be fraying.

otherwise, could be something simple like the fan clutch going out or similar, though you need to be a lot more descriptive.

fixmiester

Engine noises can be a challenge to isolate, only to find they were coming from somewhere else. Quickest way to seperate the engine from most everything else is to temporarily remove the serpentine belt from the crank pulley. Start up the engine and see if the noise is still there. If not, then it is coming from one of the external belt-driven devices. Then, using a cheap "stethoscope" can save a lot of time, and they only cost a few bucks, but you have to be really careful when using it around moving parts.
However, if the noise was still there with the belt off, then your problem is in the engine or tranny (could even be motor/tranny mounts). Odds are, it's in the engine, and likely to be, again, a belt driven item, or the belt itself. The timing belt, as puredrifter said, is very likely, but, not easy to diagnose without taking some things apart, like a cam cover. I would recommend you perform the first test, to isolate the problem a bit, then we can go from there.

Steve

hidom

Hmm, still not too sure but the car works, I took it out a couple times. It's just the noise that's making me worry. I would go through all that work but I'm afraid I might mess it up ahah. I was thinking of bringing it to the dealership and getting a diag though. The previous owner does not know when the timing belt was last changed. Also, just wondering how far from 121k without knowledge of knowing the last time the timing belt was changed before everything starts messing up? Previous owner changed the oil and tranny though but did have a flush done yet.

Luxurexus

Could it be a crack in the exhaust manifold? Thats the only thing that I can think of that would make a low bass sound...Also generally a timing belt will last a little over 100k. My timing belt lasted 14 years and 150k before I could change it. Good luck with finding the problem.

RA40

iTrader: (6)

Take the serpentine belt off and spin that top idler pulley. The bearing in mine was going south at 85K miles. The belt would vibrate and emit a high pitch squeal that changed with engine RPM. Short of that simple one, you'll have to inspect the other accessories being driven by that belt. If the timing belt hasn't been changed, don't let that go to long. There can be a high $ problem if the water pump seizes or equally if an idler does same. Get them checked.

As for fluids, although it may cost you, don't take for granted any of the fluids. Unless you see the work order papers indicating when the service was performed, do them all. Coolant with thermostat and gasket, PS, tranny (partial drain if the fluid is red), differential and brakes. One of the recurring issues we see is poor interval fluid changes.

billydpowe

iTrader: (1)

WELL...... did you remove the belt to see if the noise was still there???

python

iTrader: (4)

not sure..but im thinkin its the engine making that noise..shut it off, the noise will stop!

fixmiester

Okay, it sounds like you are not comfortable working on your car, even to perform the first step. Most folks on this forum are DIY types, so the recommendations are suitable for them. I recommend you get cozy with a good mechanic or dealer in your area; you may be seeing eachother quite often. Good luck.

Steve