Cucv extreme rattle noise

[mudman]

Sounds like you have a broken Piston Shirt!!

 

[wayne pick]

There's an adj bolt just above the fan pulley 15mm I think? There's a bracket just below the exhast manifold that u can't see unless u get under the truck and look up at it under the pump. Mine is there, but is not connected to the back side of the pump, there's a gap. Probably a missing part. Sounds crazy, but check your bumper bolts/ brackets. If they are loose they'll buzz and drive ya nuts thinking it's something else. Check the oil cooler that might be making contact with the radiator

 

[epartsman]

Here's another simple one. Check your air cleaner. I took the metal grate out of mine because it was coming apart. I heard a buzz sound that would go away at higher RPM.
I grabbed my air cleaner and it went away. Two thick washers under the nuts and Viola, no more buzz.

 

[wired1000]

Thanks for the advice! I checked that last bolt on the PS Pump bracket (bracket to PS pump)... the one that's hidden away and can only be seen from the bottom. That's tight. I'll try looking for the ones you all suggested tomorrow.

I did have an opportunity to do some more checking (once I determined that it wasn't an engine issue, I drove to work. One day at work pays for a new (to me) alternator or PS pump... so I figured it was a win). The rattle can also be caused by turning the steering wheel sharply. Now, does that point toward the PS pump? Or is it the alternator being affected by the PS pump engaging, since they're connected by a belt?

A couple more clues to the puzzle:

-The PS pump belt that goes to the alternator is much tighter than the other PS pump belt (the one that doesn't go to the alternator). Does that have something to do with it? I'll have to keep messing with them to try to get the tensions more equal.

-My truck consumed 4 quarts of oil since October. (my commute is 60 miles per day, 5 days a week, so the truck gets a lot of miles. Still seems like a lot). It doesn't seem to be burning it... there are a few apparent leaks (Class 2), so this might not have much to do with the rattling issue, but worth mentioning. I replaced the CDR valve recently, so that's not the problem.

- The PS pump fluid was pretty low. I topped it off, but haven't driven the truck since. Will report back on that tomorrow.

 

[richter1978]

Wired1000, yes I did fix the noise, there was a missing mounting bolt on PS pump. But now a similar noise is back on the 1009, I need to check out someof these new suggestions. Also on my 1028 there was a buzz/rattle when I turned w/acceleration (sp?), turned out to be same PS pump bolt loose not missing.

 

[wayne pick]

wired1000, If my math is right you put 7200 mi on your truck since October right? 4qts isn't bad and minor leaks turn into quarts over time. Have you changed the oil over that period of miles? Im a firm belever in frequent oil changes, and it's cheaper than finding an engine that runs as well as mine. I changed my oil in December and again yesterday, March 13. My odometer is incorrect becuase I have a different transmission so I figure i'd change oil every four months. Try using 30wt Rotella and Lucas oil stablizer for the summer months, We get your hot, humid weather over here in summer thank you very much. As far as the PS belt goes, I've tried to tighten the PS first then the ALT and visa versa and the PS belt ends up squeiling sometimes, a brand new correct belt. Drives me Report any findings. WCP

 

[wired1000]

I'd better change it soon... yeah... my odometer doesn't work quite right, so I've sort of lost track. Still not sure what that noise is... it's driving me crazy. I'll have some time to look at it tonite, and was thinking of advancing the injection pump a little bit, as I've heard most people have good results doing that. Also was going to try to tighten the PS pulley itself. I'll haven't looked for this bracket near the exhaust manifold, but I did check the air cleaner... that isn't it. I've got something loose near the bottom of my radiator fan shroud, but if I hold my hand on the shroud while revving the engine, it produces the noise but I don't feel it on the shroud.

About ready to take it to a shop that has "Free estimates" and let them tell me wtf is going on.

 

[epartsman]

Maybe your oil cooler lines are vibrating on the fan shroud. A few members have had holes rubbed in the metal lines there.

 

[wired1000]

Well, I fixed it! Here's what turned out to be the problem...

1) My fan shroud was loose on the lower, passenger-side corner. Tightened that up which got rid of a quieter rattle that was masked by the loud rattle.

2) That f***ing PS pump bracket... the corner that broke a while ago I had welded back together. The shop did a sort of crappy job, and the bead from the weld interfered with my 1/2" socket when I tightened it. So basically, I thought it was tight, but it wasn't. Using a smaller socket (3/8") had slightly thinner walls and was able to crank down that bolt another turn or so. All set. She's running so smooth and quiet... (comparatively speaking).

Thanks all for your advice and help.

 

[wayne pick]

Hea wired1000, Good to hear you got that fixed. Hopefully they welded BOTH sides of the tab when they did the repair. By your discription of the weld bead, it sounds like they "stick" welded the tab on one side while the bracket was still on the engine. If that's the case the tab is likely to cack again on either side of the weld. The weld bead is harder than the steel arround it. To make a proper repair, the bracket and the tab have to be chamferd, or veed out to get proper weld penetration. Mig welding- wire feed with sheilding gas is a more prefered method for a repair like this as it is more precise and makes for a neater weld on small parts. I welded mine myself by removing the bracket and mig welding both sides of the tab and lightly grinding to make sure everything bolts up flush. Don't mean to pi$$ in your wheaties, just letting you know it may crack again. Hopefully not. WCP.

 

[wayne pick]

Footnote to welding repairs, Quenching, or rapidly cooling a welded part is not recomended as it actually changes the molecular makeup of the steel arround the weld. Depending on the formula used in the steel manufacturing process, it may compromise the strenth of the steel and cause failure. This method IS used to put the "spring" in spring steel, but spring steel is manufactured with a totally different formula than cold rolled steel. Try to let welded repairs cool naturally. Sounds crazy right? It's true. WCP.