94 302HO. Tensioner bottoming out.

[Mrlilwheeler]

Tensioner Bottoming Out-
So, one day during a pull, a harsh knocking came about, and I personally thought it was a lifter. The sound went away after letting off, and wouldn't come back unless getting into it. Sometimes the sound won't come about during pulls. Mostly when I'm trying to show someone the sound. Lmao. Anyways, a month later of no harsh driving, etc etc. The smog pump locked. Shredded my belt a little. Decided to bypass the smog pump but leave it bolted on, to avoid plugging hoses, and head. Got a shorter belt, and it fit fine, had no problems. Went for a pull, and the sound didnt come about. Of course. Today during idle, I could hear a faint little knocking, and I can see the tensioner pulley bracket kinda rattling, and its making the two pieces hit eachother. I'm gonna replace the pulley finally, but should I get a slightly longer belt made, or leave it how it is? The sound was there before the smog pump locked up. It also squeals on start up after smog pump delete.

Also, should I EGR delete, after doing the smog pump delete?


94 302HO
Stock Heads, block, & internals.
Shorty down tubes to off-road xpipe to two dumped flow masters.
New alternator
New serpentine
New distributor, wires, and plugs.
New Coil.

Adjusted timing to correct degree.
Sorry if there's anything unnecessary. I'm only 20, fairly new to turning wrenches.

 

[jozsefsz]

I think the knocking happens when the tensioner is fully relaxed, meaning you probably want a shorter belt and not a longer one. The squealing tells me this as well.
EGR delete isn't tied to smog pump delete in any way, you can do neither, one or the other, or both independently depending on your 'off-road' needs.

Be advised EGR delete will throw up a code with light unless you tune it out or use a resistor / the original sending unit. Plus it will increase your NOx emissions significantly. I've never seen the AIR pump do anything to emissions that was noticeable.

 

[Mrlilwheeler]

A shorter belt? The belt I have fits snug, the one fit before was a little too long, you could see the slack bouncing from the alternator to the power steering pulley.

 

[jozsefsz]

Yes, clacking and squealing is most likely caused by a belt that's too long. There are stops on the tensioner that can cause clacking in both cases, too short or too long, but I've never seen the too-short clacking happen unless the belt is ridiculously too short and you really forced it on there. At which point yeah, that's not the right way to do it and you need a longer belt. Or if the tensioner spring is actually completely weak or broken, which yours might be after the air pump failure. Since you mention is wasn't taking up slack on the slightly longer belt, your tensioner could very well be broken (the squealing points to this as well).

Once you're confident your tensioner is good, use the alignment marks on the tensioner to determine which (too long or short) is the case - the single-line on the arm casting should be between the two lines on the casting. The alignment marks are only meaningful if the tensioner is working properly.

If you need slightly longer or slightly shorter, you can get 6-rib belts at any local autoparts store with length differences in 1/2" increments, so very probably no need to have one made. Shoot for one that puts the alignment marks within the range but a little on the "tight" side, as belts will stretch over time. Various makes of belts often have slight length-differences (a Dayco belt might work while the equivalent Goodyear might be too loose) so take your current belt with you. If your local parts folks are cool they'll let you try one on in the parking lot before you buy it.

 

[Noobz347]

The tension pulley [must] be pried [up] when you install the serpentine belt. That may be stating the obvious but it wasn't mentioned here and I want to ensure the OP is doing that when he's installing the belt that he thinks is too short. The entire length of the belt must be seated in the belt lands of each pulley and each pulley must be in a firm and fixed position with [zero] slop, squeaks, or grinding noises.

If you have constant 'clatter' no matter what you do, I would suggest that you have a pulley out of round, out of alignment, or has a wrecked bushing or bearing.

 

[Mrlilwheeler]

Will replace the tensioner tomorrow & hope for good results. I'm running 89.5 6 rib belt, at the moment, and the tensioner does slightly clatter from time to time. Thanks for the help!