this started a couple of weeks ago. when i turn off my engine, there is a short rattle. motor mounts have been replaced. this sounds like it is coming from the engine. i haven't had a chance to open the hood and have someone else shut the car off so i can get a better idea, but just thought maybe this was something simple.

timing chain tensioner?

191,000 miles regular issue?

 

timing chain likely, video of the sound would probably make it clear

 

i'll get a video up tomorrow. if it is the chain, are we talking a full replace or just the tensioner? is this something i can do with mild mechanical skills (brakes, valve cover, etc?)

 

my freinds car rattled on shut down and it sounded like from behind the engine and it turned out to be an exhaust hanger holding the flex pipe was broken. make sure nothing moves down there and nothings broken.

 

Is it a 6spd? My manual transmission makes a slight rattle when the engine is turned off, as did my friends manual G35 when it was brand new in 04-05.

 

Dumb question but are you in the car every time?
I thought mine rattled every shut down, but turned out to the the fan/radiator rattling.
broken fan and radiator mounts.

 

My car rattled on shut down too. It was the pre-cats. Gutted them and sound is gone now.

Try revving the engine in park and see if it rattles as the rpms drop. My pre cats also rattled in that scenario.

 

sorry about not posting the vid. i'll try to get one up soon. it makes the noise when i shut the engine off. im pretty sure my oil is good but ill give it a look here when i go to work. it also makes the noise when i rev it in low rpm. always suspected pre cats but this sound is a tad worse and it never did it on shut down. im hoping precats but i fear bad timing chain tensioner.

 

aight just made the video. checked the oil, its fine. what im talking about in the video is the car wont usually stay started without a little gas pedal. i figure thats more the maf and intake needing cleaned. will attempt to upload vid now.

 

 

lemme know if that vid isnt working. should just have to click on it.

 

actually after reading about gutting the precats i hope its not that either. cmon MAF!

 

I replaced the precat closest to the firewall and...the rattle went away!

Cvicvogel

 

does that rattle sound the same?

 

A friend's 2003 Max does exactly same. It seemed to have developed when the spark plugs were changed and new ones (oem) installed, though I think the change is more coincidental than connected to the problem. It is really difficult to locate the sound. At one breadth it seems to come from the top of the engine bay at another you'd think it is from somewhere lower on the passenger side.

 

Sounds like the timing chain tensioner...

 

Definitely doesn't sound like pre-cats. Sounds like the timing chain.

 

Speaking from the 6th Gen point of view, the bad tensioner whines; this one clatters/rattles sort of.

 

some confusion here. The tensioner itself might whine but the sound here from a bad tensioner is chain slap since the tensioner doesnt have enough tension on the chain. Somewhat of a common issue on 5.5 gens, particularly in winter when startup temps drop and it takes longer to get oil pressure built up in the tensioner

 

in the process of doing this(all chains. and guides ),water pump,but wish me luck to not jump time (hopefully)....im wanting to get away with changing the plastic clips on both cam tensioners instead of having to remove the cams sprockets....we'll see




.02

 

had my mechanic look at it. he said it was the tensioner or the water pump. sold it today for 3k and bought a prius. thanks for all the help over the years, maxima.org!