Lets play "Diagnose that noise over the internet"

[DevilSperm]

I'm working on this car for a friend of mine so he can drive the thing for once in the 3 years hes had it. Its got this noise, behind the intake. Its too loud to be the lifters, as I can hear them too. And It's too fast to be a rod knocking. I'm thinking it could be the balance shaft wobbling around but I've never heard one do that before in a 4g63 so I'm not real sure.

The motor was supposedly rebuilt before he got it. The odometer reads 87,XXX so why it was rebuilt I don't have any idea. The compression #'s are relatively low, 125-130 range. Another theory was a valve sticking and its resonating through the intake and I'm hearing it back there. Anyway, who's heard a balance shaft eat a bearing and what does it sound like?

P.S. 91 talon awd and bone stock

 

[DevilSperm]

On a side note; I've never been dumb enough to install a balance shaft out of phase, so maybe thats what it is, I wouldn't know. But, this is more of just a noise and not a vibration so to speak. If that helps any.

 

[1stGenRocks]

When i spun my balance shaft bearing on my 1.8 it sounded like rod knock. Not quiet by any means. Drain the oil and check for particles. Is it any different hot or cold?

 

[DevilSperm]

When i spun my balance shaft bearing on my 1.8 it sounded like rod knock. Not quiet by any means. Drain the oil and check for particles. Is it any different hot or cold?

No it doesn't matter whether its hot or cold. At idle its kind of there but not to bad, but as soon as you give it gas it really noticeable, and at WOT is embarrassing. I'm going to check the phase tonight just to see if that could be the cause. But the way you talk about the way yours sounded I'm leaning towards a bad bearing.

 

[Kloopofadown]

I dont think the phase should have anything to do with noise. If It was outta phase, your engine would be shaking like a mofo. I had a broken b-shaft belt for about a year and it just shook allot. BUT seeing how that would be easy to check, go ahead.

 

[DevilSperm]

I just checked it. It's in phase. The other option I guess would be it wobbling around in there. Any other options that I may not be thinking of?

 

[Kloopofadown]

I'll just throw this one out there, AC compressor bearings?

 

[awdtalontsi1992]

I would suggest you grab a stethoscope and try to narrow down the search area. Did you try pulling the valve cover to check everything in the head? That is where I would start and work my way down. A quick thought in my mind......starter gear not disengaging?

 

[DevilSperm]

Definatly checked the starter and AC. I do need to scrounge up a stethoscope though. I tried the vacuum cleaner hose method and it didn't work out so well I haven't pulled the valve cover off, I'm not sure if he wants to buy a gasket. But I am fairly certain is not coming from under there, it seems more under the intake, which leaves the starter and balance shaft.

 

[RoasT BeeF]

I had a 1g gsx that spun the rear bs bearing. The bearing came completely out of the hole so the shaft was just wobbling around and widened out the hole so much that a new bearing wouldnt even go back in. It sounded similar to rod knock but not exactly the same.

 

[Defiant]

Yeh, out-of-phase won't make noise, but the shaft bearing sure will. It'll make more of a deep, klonk-klonk as it rings the block like a bell. You might be able to feel some looseness if you use a probe through the phase-check peephole.
Mechanic's stethescopes should be everywhere, Lisle sells one through Napa and the like, and Harbor Freight has them for almost nothing. One of them should pinpoint the source very quickly, or if you have a long enough screwdriver, you can put that to the area and to your ear, and it works almost as well.

 

[wibblersnatch]

Did it sound like this? http://videos.streetfire.net/search/noise/1/04cff26e-334d-426e-8218-573fc5c07e23.htm

My car was doing that and ended up having a balance shaft floating around in my block.

 

[adidalax]

I had an idler pulley go bad on my in my mom's minivan when i was 17. sounded like rod knock and freaked the hell out of me. turned out that the bearing was going bad in it as well as the A/C compressor. It was funny as hell actually...the damn thing popped off when i was driving bc we never fixed the damn thing. All I heard was *CLUNK* and the noise was gone. I looked in my rearview and it was rolling down the street behind me !! Anywho...try taking a bright-ass flashlight, looking down there, and make sure none of the belt pulleys are wobbling at all. If so, you can suspect that it's a bad bearing on that pulley. Any way you can take some kind of recording of it? You can post it on my website if you need some online storage space....

 

[DevilSperm]

I've been working all weekend so I havent had a chance to check it out more. Tomorrow Im going to pull all the belts and make sure its nothing there. It really sounds like its on the tranny side though, but Im at the point where Im going to have to start eliminating things one by one. Then its off to get a stethoscope. Im hoping he just sells me the car so I can put my own engine in it