andrewmac

iTrader: (2)

I have a feeling I'm not going to like the outcome of this. Girlfriend bought a '99 white maxima (auto tranny) for cheap a few months ago. High KMs (320,000kms on the engine) but body was in good shape, motor sounded good and it drove fine. Not to mention the price was great ($500). It needed a new knock sensor, so I figured why not tear the whole upper/lower intake manifolds off and give them a clean and replace the gaskets/air filter so she'll breath well.

Did all that. Put it back together. Changed the fluids (except for tranny - its a bit too old I didn't wanna risk slippage) Told her to crank it and as soon as she started cranking it I told her to stop. Bad noise. Very loud pinging. Sounds like metal on metal. I had a rod knock in my 01 engine before I swapped it, and it had nothing on this ping. The rod knock was more of a consistent tapping and the noise was more dull than this one. This is more of a loud ping. It almost sounds like it's happening outside the engine, but after a full investigation there's nothing that could be doing it so it must be inside.

At first I thought, oh **** no, I dropped a screw/socket in the engine. I was very careful around it and covered it while I'm not around. Plus I'm not missing any screws/sockets. Also, I would have thought by now after cranking in short bursts (3-5 seconds) 5-10 times to investigate the noise it would have caused the noise to change by moving the screw/socket to a different part. It's very consistent and changes in frequency as the engines RPM changes.

I'll post a video as soon as possible but in the mean time does anyone have any educated guesses? It seems concentrated on the top of the engine, towards the left a bit which is making me hope it's the timing chain tensioner. Most of the videos I've watched of that though are more of a rattle than a ping.

Amerikaner83

iTrader: (17)

so it sounded fine before you tore it apart, now it doesn't? Something you did caused it. Is something not tightened enough? Tightened too much?

D.Stillwell

I'm uneducated, not smart. No way I can make an educated guess.

andrewmac

iTrader: (2)

Yes, it was running and sounding fine before hand. It's definitely my fault I'm just hoping a recovery might be possible. I'm getting her to email me a video of the noise so you guys can hear it.

Fakie J Farkerton

iTrader: (51)

..... wow

And OP, I have to side with Amerikaner on this.

andrewmac

iTrader: (2)

I agree completely, it's something I did. I just feel like I'm in a position where the car hasnt actually been ran with the noise yet, only cranked a bit, so if it's something inside the engine I may still have a chance to get it out before the damage is severe.

njmaxseltd

iTrader: (19)

Waiting for the video...

Climaxx

iTrader: (4)

^

Maximeltman

iTrader: (11)

You must have dropped something down the intake manifold. Must have. Now whatever went down is riding on top of the piston and smacking the head...I'd tear it apart again and take a magnet snake and try to slip it into the intake valves or through spark plug holes.

njmaxseltd

iTrader: (19)

You wouldn't hear a loud ping while cranking if a screw or some other small item was dropped into the intake. We've heard 5th gens and 4th gens with the variable intake runners run with set screws in the cylinder heads. It's a very distinctive sound once the engine is running.

Still waiting for the video, until then we're all just guessing.

deathwobble

iTrader: (1)

Could always just tear apart what you did and see if its something obvious....been down that road before hahaha

carsnwomen91

Yep lol

dwapenyi

iTrader: (3)

Doing the video is only going to produce more damage to the engine. Forget the video. Take it apart again if you want to save the motor.

Also, you can change the tranny fluid in a gentle way by dropping the old fluid, measure it, then replace with new fluid of the same amount thru the dipstick. Doing this several times will bring back some liveliness to the tranny...it'll be happier to downshift etc.

ChrisMan287

iTrader: (34)

In for the video.

Maximeltman

iTrader: (11)

I know you didn't mention this but maybe its the starter? You mentioned it sounds like outside the engine. Oh if you decide to post a video make sure to pull the fuel pump fuse.