nothing but issues after having Metco 4lb lower installed...help with correct belt?

Sorry for the long post.
1. Had a shop install Metco 4lb lower, 3.2 alternator pulley, and LT headers. They put K080794HD FLEETRUNNER MICRO-V 8 79.45” belt on…..Noise starts as an occasional chirp then progresses to all out squeal.
2. Seems like noise is coming from tensioner pulley, makes sense since it’s the only factory one left. Had shop replace tensioner pulley with Metco HD idler and did Roush tensioner upgrade at the same time. This time they put on K080797HD FLEETRUNNER MICRO-V 79.62” belt….squeal is gone, but now a rattle noise under light acceleration that progresses to loud wrapping noise. With dyno tune date quickly approaching took it back to the shop. Everything looks good to the eye. Tried reinstalling factory tensioner and pulley loud wrapping noise still there. Last resort try another belt. The only one in stock is extremely tight K080790HD FLEETRUNNER MICRO-V 78.9”, wrapping noise goes away. Drive home 40 miles on the highway noise free. Next day squeal is back, but not the really bad wrapping noise. I had the old K080794HD belt and was able to get it on, but it’s still pretty tight. Mild squeal still. Make it 2 hour drive each way to dyno appointment.
3. While changing belts I noticed a slight squeak when turning the alternator by hand. After trying all the above, I’m thinking it must be what is causing the noise….Replace alternator, also move up to recommended 3.5 alternator pulley, and go back to the longer 797 belt….shakedown cruise seems fine, then the after about 10 miles the wrapping noise comes back. Put the smaller 794 belt on and it’s also making the wrapping noise now. Also put the Roush tensioner and Metco idler back on since it did not seem to have anything to do with the noise.
4. Doing research trying to figure this mess out, I see a post on SVTP forums saying don’t forget this spacer on lower alternator bracket when using the Metco kit. I notice the spacer is not there on my car. Make a spacer and put it in….still wrapping noise, but much quieter.
5. I call Metco for help. They recommend 81.5” long belt with 3.0 upper, 4lb lower, idlers 3x100 and 1 x90, and 3.5 alternator pulley. All of the belts I had been using to this point were a lot shorter, so I figure I’d give it a try. The only belt in stock that day was K080810HD FLEETRUNNER MICRO-V 81.04”…..Shakedown cruise it’s silent, after 100 miles only occasional squeak/squeal. The the belt is pretty loose, but not so loose I could get on without removing snub idler. I’m not sure if it’s slipping, but at least I’m not afraid to take the car out and enjoy it. I’ve read lots of people complain about he green belts, but I had one for over a year before all this with no issues.
My question is should I get the K080810RPM belt? Will the K080797RPM be too tight?

Something is out of alignment. The alternator is the most common culprit followed by the tensioner. You can use a piece of 1/2"-3/4" wide flat iron and lay the edge across the crank pulley and see if the alt/tensioner looks out of alignment. Dayco makes a small laser tool to check alignment if you prefer.

My green belts always make a chirping noise on a cold start up. But eventually stops after a few minutes.

This is one reason why I haven't installed my 4 lb lower yet in fear of alignment issues.

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Ok, so I might have an idea here. I installed a Metco lower this past winter. I did some reading and the lower idler that gets installed on the new Metco bracket can cause some alignment issues depending on what spot it's placed in. Some guys said they needed to put the idler in the highest position (gives most belt wrap on lower crank pulley) on the Metco bracket to have the alignment work out ok. Might want to move that pulley into the highest location if it is not.

I would try a regular belt. All the squeaking and chirping might be from the green belt.

Many years ago I had a issue where I kept having to replace the factory tensioner/pulley due to a chirping noise. This started shortly after installing the Metco. After the second tensioner pulley started chirping I contacted Metco. They had me send the lower hub back to inspect. They had certain tolerances for these and mine was on the higher end. After they corrected the issue it’s been trouble free.


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Update: drove another 40 miles....810 belt must have stretched and is making noise/slipping...I double checked the 810 belt and it is definitely too long...maybe it stretched, but I can get it off without removing the snub idler now...I went with the 810 after Metco recommended 81.5 inch belt, so I think next i'm going to go 2 sizes down and 1 up from the 797 that was just a little too tight and try a 801. Only have 801 and 806 left, I've tried all the others....I will check idler orientation when under the car putting the belt on....I think the bottom idler is already in the top position because it's tight getting the belt between the crank and idler.

Man, way to much belt swapping.

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You really need to check alignment before buying more belts. Went through this on a friend's car. His would shave a rib off every time. We figured out it was the lower, but he never did anything to fix it.

Just put the 797 back on so I could return the 810 and exchange for 801...Roush tensioner is at about 75-80% flexed. Miraculously no noise on 10 mile round trip to parts store. Maybe it will stretch and end up working out.

This problem showed up after the metco install. It’s not a belt length issue.


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So this is all on pump gas? Seems like a ton of boost (21?)

Might be able to run the 3.0 upper with the factory lower....probably more pump gas friendly. Or, once you get the 4lb lower all figured out and aligned....spin the upper with a 3.2.

c6zhombre said:

So this is all on pump gas? Seems like a ton of boost (21?)

Might be able to run the 3.0 upper with the factory lower....probably more pump gas friendly. Or, once you get the 4lb lower all figured out and aligned....spin the upper with a 3.2.

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I’m running 20.4 lbs boost up from 16.8 with stock lower. 93+Torco. Gained 70tq, which is what I was after for street cruising. I don’t think a 3.2 upper will fit with 100 snub idler..car runs good and I don’t really beat on it, so I should be ok


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MG0h3 said:

This problem showed up after the metco install. It’s not a belt length issue.


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Bingo.

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Could just be the green belts. I remember several years back dealing with squeaking that I couldn’t stand when I ran Gates (I think, but it’s been many years). I ended up going back to a Gatorback and it’s been perfect ever since.

black 10th vert said:

Could just be the green belts. I remember several years back dealing with squeaking that I couldn’t stand when I ran Gates (I think, but it’s been many years). I ended up going back to a Gatorback and it’s been perfect ever since.

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Gatorbacks are now Continental...I had a hard time finding info for belt lengths. Auto Zone sells them, but they did not have the size 4010801 I needed in stock. I may order one.

black 10th vert said:

Could just be the green belts. I remember several years back dealing with squeaking that I couldn’t stand when I ran Gates (I think, but it’s been many years). I ended up going back to a Gatorback and it’s been perfect ever since.

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How have you been stranger?

03cobra#694 said:

How have you been stranger?

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haha, hey Brad! Yeah, I’ve been kind of MIA on here for the past couple of years so I’m kind of catching up on what I’ve missed! I still have the Cobra with a whopping 17k miles on it, but have been hanging on other forums while modding my 4Runner and Miata. I am moving down to your neck of the woods though. 2.5 miles from the FL border in GA. I see you’re still doing the mod thing, so that’s good to see some stuff is still the same here

black 10th vert said:

haha, hey Brad! Yeah, I’ve been kind of MIA on here for the past couple of years so I’m kind of catching up on what I’ve missed! I still have the Cobra with a whopping 17k miles on it, but have been hanging on other forums while modding my 4Runner and Miata. I am moving down to your neck of the woods though. 2.5 miles from the FL border in GA. I see you’re still doing the mod thing, so that’s good to see some stuff is still the same here

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Good to hear Brian. Yeah, still here when I have time.

I'm curious as to what pulley you used on the roush tensioner? When I upgraded to the roush part I wanted a metco pulley, simply to match the rest of my pulleys. They said they didn't have one that would fit.
I assume you spaced the roush tensioner correctly? It doesn't just bolt on, it needs spacers