Hi all, I have a 2006 MT Enthusiast with 46k miles. Recently my car started making this grinding noise on starts. I start the car and it revs to 2500 rpm (I feel is too high) and at the peak it makes a grinding noise which lasts for about half a second and then it's gone. It seems to only happen when I first start the car and not any other time. I've read other threads that It could be the type of oil I use, or the "timing chains rattling a bit as the tensioner(s) get pumped up". Any help?

 

Low oil will cause a nasty sound as well.

 

That's what I was thinking... I read another thread that it could be low oil causing metal fragments which is destroying my engine. I bought the car in February and only drove it 1370 miles do you think it is the infamous oil consumption issue? I bought it at a Mitsubishi Dealer in February with a 3year/36k mile warranty, will that do anything?

 

Mine's been doing this since I got the new motor. I've seen suggestions about tensioner to starter issues. When I pulled my timing cover off, I saw where the timing chain had scored the inside of the timing chain cover. I use a magnetic drain plug and found metal attached to it, but finely ground. I dunno if oils precipitate anything under heavy use, but I'm guessing it's some engine surface. I might try adding more oil and see if that helps with tensioning the guide quicker. I don't consume much, if any, but it's hard to tell because I have a sight rear main seal leak. I might go through a quart every 3k with that leak.

 

I'm probably going to take it down to the dealer tomorrow to see what they have to say and I'll probably have them do an oil consumption test. Yeah I doubt oil would precipitate like that. I was also informed to check the oil pan for any shrapnel. Does the revving at 2500 rpm have any relation? I could have sworn when I first got the car it started at around 1800 rpm... I'm worried! Hopefully my warranty will help, or lemon law?

 

I had this for about a month and it drove me crazy.

Is the 30 second grind a dull, deep-toned, growl-like grind that sounds like it is coming from the front of the transmission/back of the engine, and a little towards the passenger side?

I finally gave up and dropped my transmission to find out what it was and as it turned out, there was too much grease on the input shaft of the transmission. So on cold starts, before the transmission would warm up, the grease would be so viscous the throwout bearing wouldn't move and was holding the clutch disk up against the flywheel. The pressure was light, so it just made like a harmonic grind almost, but I have a feeling your issue may be related. To the throwout bearing.

Good Luck

 

Half a second? It's your timing chain rattle. Common with nissan motors. People either just live with it, or spend the cash to get the hydraulic tensioner replaced. I have read multiple threads and posts from nissan saying that if its .5-1sec then nothing to really worry about. If it is more constant and lasts for a while, then get it looked at. That's at least what i read.

2500 seems normal for a cold start, when the engine is slightly warm or has been ran recently, it will rev much less at start up.

 

Whoops, definitely misread OPs post. +1 what JERZ350Z said. It's not something to worry about, but if you google, someone on a morano forum (i believe) picked apart the service manual and figured out a way to fix the timing chain problem without removing the front cover. if I come across it again I'll post a link.

 

Definitely all ears on this one

 

Okay, thank you! I hope it's the chain tensioner and not something worse. I actually found a video:

Link:
The very first start up in the video is what I think* I experienced (only twice) but the other start ups in the video I don't think I have those. I started it this morning without any problems and I put in a quart of oil in today. I don't think a quart of oil per 1370 miles is excessive enough to get a new engine. I hope it's not metal shrapnel like in the video .

 

Yes, that's what i have for going on 2 years now. The first startup

 

http://x.nissanhelp.com/forums/quest...-05-quest.html

 

Thanks for the link Rob!

 

Any time, I hope it works for you. I never actually read into it too deeply, just remembered seeing it.

 

I always figured those access covers were for exactly that, replacing those tensioners....otherwise why would they be there. Typical procedure is to remove the whole front cover and replace the chains too. The guy with the Quest successfully did it and it ran fine for 18000 miles....but he said he later had another issue with it, but not really with the hydraulic tensioner, but i think with the arm the tensioner pushes out. So unsure if this is a permanent fix, or if the entire thing should be replaced anyway.

 

BUMP. Happened last night!

 

Ha! mine did this a few times during the winter months, then nothing for ages. I read this thread two days ago, and the first time i start it up after sitting overnight with the plenum off, it did it on startup, hasn't done it again since.

 

Sigh, I need to check the oil pan for shrapnel and take it to the dealer for an oil consumption test... I'm so damn lazy.

 

My car does this on random startups. I'll go months without it and then 2 weeks where it happens several times. I don't give a sh*t about it.... and my motor has oil up to the H mark so I don't believe it's a low oil issue. I have an 06MT as well (NO OIL CONSUMPTION YEEEEEE BOIIII!)

 

Mine seems to do it with the same frequency as yours, MikeBit.

I have noticed that when it does do it, that the oil pressure gauge doesn't start to move up until it's made the noise.