I've got a few questions for you guys. I've read a few of the posts on my problems but have some morespecific questions;

1. I have the discussed "clinking" noise that occurs when I get on the gas from a stop or rolling, doesn't matter. I read that it is detonation, correct me if I'm wrong though. My question is: how is detonation cured, if it can be cured, and is there any way to definitely determine if it isdetonation?

2. After the truck has come out of closed loop, warmed up and idling around 600 rpm, I get this fluttering noise, only at idle (almost sounds like if you were to blow into a fan when it's running at medium speed).I think that would be the best way to describe it. It seems to be coming from the exhaust somewhere. I have true dualsout the backand it can be faintly heard on the right side (or left cylinder bank if looking at the front of the truck). Any ideas? It's not a big issue just an annoyance.

3. The clunking noise/feeling that everyone seems to have has plagued me also. I'm almost positive that it the steering shaft as mentioned in other posts. My question is; is it the upper or lower shaft? I found in the LMCtruck catalogue the upper shaft with needle bearings which claimed to be the fix for the loose and clunking feeling. Can anyone shed some light on this? Anyone bought this shaft? and how hard is it to replace? Here's the link to the catalogue page: http://www.lmctruck.com/icatalog/ce/t.asp?page=54

Thanks in advance guys,

- Justin.

2003 Reg Cab Silverado 2WD 4.8L

 

1. U sure its coming from the engine and not the exhaust or drive shaft?
2. You have an exhaust leak somewhere.
3. Intermediate shaft (the one in plain view when you open the hood). PM Argon about the replacement shafts. The grease in the intermediate shafts gets hot and runs to the bottom of the shaft and therefore causeing the shaft to click and make noise (nothing to deaden the noise or lube it). I know GM makes a greaseless shaft now.

 

1. I'm pretty sure it's not the driveshaft, I've heard a U-joint clunk before and this doesn't sound like it, it's more of a very fast "clink". What else could make a noise with the driveshaft? The sound doesn't last for very long. When on the gas, fairly liberally, it'll make the noise for maybe a second then go away, if that helps. I'll see if I can get a clip of the noise. I just hate taking **** like this to a mechanic, I don't want to pay them lol

2. If it is an exhaust leak why isn't the truck any louder and why is the "flutter" not around when the truck is cold and idling higher? Is there common spots for leaks I can check if it is a leak?

3. I'll ask him right now, thanks!

- Justin.

 

1. Well if it is coming from under the truck it could be dry bearings in the U-joints making the noise. It might not be "shot" yet but the lack of grease could make them click under load. The slip yokes on these trucks have a lot of play in them and can make noise too, but you can usually feel it. Maybe try greasing the slip yoke?
2. Small exhaust leaks sound like helicopters all most, but they don't have to be "loud". It could be a leak on the gasket between the manifold and the downpipe, or between the downpipe and cats. Or maybe just a pinhole somewhere. Let her cool down all they way, star her up and jump underneith. Feel around the pipes for exhaust coming out around the gaskets and stuff. Follow the noise if you can. It might flutter more when cold because it is dumping more fuel into the engine when its cold and therefore increasing exhaust pressure during idle, (eduacated guess not fact).
FYI: My truck makes some fluttering noise at startup whern its cold every now and again. It always goes away when it it warm so I never looked into it.
3. You find out anything?

 

1. Forgive my ignorance, but could you explain a slip yoke? I looked for a definition of it but came up empty.

2. I'll check those problem spots. However, I think you havemy situation backwards. I get the fluttering noise when the truck has warmed up fully. No flutter when it's cold. I'll get underneath this weekend maybe, just got some more god damn snow and rain, too messy right now.

3. I tried to PM him the other day but it seemed to fail to send, I'll try after this.

Regards,

-Justin.

 

1. The slip yoke is the part of the rear drive shaft that comes out of the transfer case. It literally slips over the output shaft and connects it to the main drive shaft. If you unbolt the rearmost drive shaft and pull it towards the rear of the truck, the entire thing will come out of the transfer case. Throw a big glob of grease inside the slip yoke and slide it back over the output shaft. Bolt it back up and thats how you grease your slip yoke.

2. Sounds like an exhaust leak then. It might be a bitch to find but I bet its a gasket somewhere between exhaust components.

3. If you look up "greaseless intermediate shaft for Silverado" on the web you might find one for around $75 bucks or so. GM charges $90 to the public I believe.

 

Alright, I'll give everything agoing over when the weather gets a little better, I really wish I had a garage.

And argon gave me the PN for the shaft so I should be set with that.

Thanks for all your help!

-Justin

 

Welcome, good luck!