Mechanics

WHAT IS THIS NOISE???

1995 Nissan Altima

Noises problem
1995 Nissan Altima 4 cyl Front Wheel Drive Automatic 117K miles

For the last 2 or 3 months I have had a strange rattling/whining noise coming from the front of my car. When the mechanics check, they say it's coming from the location of the oil pump/timing chain. Also as I am driving, I hear this whining noise in the gas pedal. All of this calms down (not completely) after the car is warmed up. I have had just about everything replaced: chain (and all the accessories with it), oil pump, timing cover, water pump, etc. Except for the engine itself, all the parts under the hood are new.

The latest is that others have listened and thought the noise could be the idler pulley. I did the wd-40 test, and the noise disappeared and came back. When the mechanic took the belts off (left the pulley on), the noise was still there. I checked again with others and they suggested the noise was coming from the timing chain sprocket. Someone else suggested the timing chain guide. Took back to the mechanic and he said that when he had the car before he checked all that. Everything was fine. He even replaced the bearing for the sprocket.

It has now been about 6 months with this noise and still no relief! PLEASE! Can someone help me figure out this awful noise?
Avatar
DGpurple95
May 13, 2009.




Has the timing chain tensioner been checked. It may not be holding the chain tight enough?

Racefan966
Jun 8, 2009.
Yes, the tensioner has been checked. The chain is on tight enough.
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Tiny
DGpurple95
Jun 8, 2009.
Ok so we know for sure that the tensioner is hold the pressure under a load? Have you use an automotive stethiscope or long screwdriver (hold the handle end up to your ear and the other part on the part or location of the noise) to listen to the engine to pin point the exact location of the noise? You can put it on the alternator or the bolt on an idle pulley or the power steering pump etc and listen to them and pin the location of the noise. Let me know what you find.

Racefan966
Jun 9, 2009.
Thank you for your ideas. I think I am going to have to go to the nearest Nissan dealership so they can do a diagnostic and try to help me find the problem. I'll let you know what comes out of that.

I have attached a link of the noise I recorded this morning. Hopefully it came out well enough for you to hear it. If not, let me know and I can redo it.

http://www.youtube.com/watch?v=LVoshc89o6Y

Tiny
DGpurple95
Jun 9, 2009.
OK I hear several things. I hear a power steering pump growling. I hear an exhaust leak and with it infront of me with a stethescope it sound like the timing chain is very loose and hitting the cover and the cam sounds like it might be trying to seaze (gualded cam jurnals) and if I heard right it sounded like it backfired? My question is what the timing chain grears and tensioner replaced or just inspected? If it was just inspected that really don't tell the story about what it is doing once it is moving and the tensoiner has the pressure on it. Let me know about the replacement or inspection of the timing components. If you look over the pic you see the cam chain on top but below is the main timing chain and that is what I think is causing all the noise. I would have replaced it all as I think the tensioner on the main (long) chain is allowing the chain to jump around and so you are heaing it hitting the guide on that side. Here is the pic of what I would have replaced.


http://www.2carpros.com/forum/automotive_pictures/249564_58222_1.jpg


Racefan966
Jun 10, 2009.
Thankfully the car does not backfire. It may have been a finger brushing over the mic. As for the timing chain, the tensioners were replaced when the timing chain was replaced. The bearing for the sprocket was replaced, and the upper guides were recently removed.

Others who heard the noise said it could possibly be the idler pulley. We tested that theory by spraying wd-40 or silicone spray on it, and the noise went away. Once it dried it came back. Took it to the mechanic and he took the belts off and left the pulley on, and the noise was still there, so we never replaced the pulley.

I think this week I'll be going to Nissan to have them check it out. Hopefully the diagnostic will tell me what's the next step. Please, in the meantime, if you have other suggestions, I'm willing to hear them! Thanks

Tiny
DGpurple95
Jun 10, 2009.
Well the noise is in the front from what I can hear and it sounds like it could be in the timing or cam area. Now I do have a question has the oil pressure ever been checked for actual pressure with a test guage? If not it would be worth checking.

Racefan966
Jun 11, 2009.
Everyone else I have spoken with so far say it's in the front fo the car. A few say it's still in the timing chain area. The rest are still liking the idler pulley theory.

The oil pressure has been checked recently, and with a test gauge. The last mechanic who had my car couldn't give it back to me because it had strangely lost oil pressure. This was after he had replaced the oil pump (he thought that was the cause of the noise). After some messing around with it, he was able to get the pressure back. Of course, the noise was still there.

Tiny
DGpurple95
Jun 11, 2009.
I do not support the idler pulley theory because you said you removed all the drive belts and started so the pulley would no longer be moving therefore it can not make noise, or at least it shouldn't. Now if you feel it is the idler pulley then pull it off and spin it in your hand and feel the bearing for roughness and listen to it for noise.

Racefan966
Jun 12, 2009.
Well, my car is now at a Nissan dealer by me being checked out. They could not pinpoint the location of the noise other than the front area of the car. This diagnosis is after the car was apart. They are almost as frustrated as I am right now. While they have the car open they will replace a few things that look a bit worn (tensioner, guides), and hope that the noise goes away, or at least is not as loud. So far the only constant is pretty penny I am paying out each time the car is opened up.

Another option the mechanics at Nissan gave me was to replace the engine with a 'pre-man' engine, in the event the first option of replacing the parts doesn't work. With this second option comes much more money to shell out that I just don't have. I'm ready to pull my hair out!

Tiny
DGpurple95
Aug 28, 2009.

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