Video--terrible engine noise-acceleration problems

https://youtu.be/KpX38seodL0


It seems to come from either the Supercharger or the tensioner pulley right before it... is there anyway I can know for sure?
What do you think it might be?
I have ordered both tensioners and was wondering how difficult are they to replace on series 1?
I have also ordered the Supercharger coupling and oil... still need to find bearings and the seal for the right price... Is this also a relatively easy fix?

I am also having issues with the acceleration- I feel like I am only getting 20% power... I have had issues with the gas tank and it could be because of dirty fuel clogging the injectors, but I used the injector fluid stuff that usually helps - without results.

Could this pulley/sc noise trigger some sensor that then would limit the power?

I'm guessing it's the supercharger coupler.  

My tensioner pulleys have always squeeked when they're going, not rattled, and they won't cause the power to fall off until they fail and shred a belt.  Then you're dead in the water.  

I haven't had a coupler fail but I watched a video of a bad one on YouTube and it did make more of a rattling sound.  I have driven a 95 SC which felt like it had no power, and in retrospect I believe a failed SC coupler was the problem.  When the supercharger isn't turning, it blocks the air intake and the engine makes way less power than a naturally aspirated engine.  

You can pull the supercharger snout and change the coupler  yourself, but you're not going to change the bearing in the snout.  You'll have to send it off to ZZP or Intense Racing to have it rebuilt.  The rebuild process damages the original pulley most of the time, so don't do like me and have them put the old pulley back on.  Go ahead and upgrade to the modular pulley system unless you know you'll never want to mod the engine.  If you want to stay stock, have them put a new stock size pulley on.

If the tensioners are the same on series 1 as series 2, the front one is easy to change and the back one is more complicated because the coolant routes through it.  The rear tensioner is difficult enough to do that you might as well replace a few other things while you're in there, like the water pump, camshaft position sensor, and the heater hoses. There's a couple plastic coolant elbows attached to the rear tensioner that should be upgraded to metal aftermarket elbows.  If you've never done the rear sparkplugs, they're easier to get at without the alternator and rear tensioner in the way.  Also, the engine 02 sensor, if you can manage to break it loose at all.  

This is a lot of work and it's best if you have a garage to work in and can have the car down for however long it takes.  For me, it can be a month or more while I ask questions on the forum and work through all the incorrect parts that tend to turn up.

Sorry if that's a bummer, but it can be done!  As a n00b mechanic I've put ridiculous amounts of time into this car, because I am inexperienced (well, not so much anymore!), but she's 24 years old now and still runs and performs like a new 97.

Jack the R wrote:

I'm guessing it's the supercharger coupler.  

My tensioner pulleys have always squeeked when they're going, not rattled, and they won't cause the power to fall off until they fail and shred a belt.  Then you're dead in the water.  

I haven't had a coupler fail but I watched a video of a bad one on YouTube and it did make more of a rattling sound.  I have driven a 95 SC which felt like it had no power, and in retrospect I believe a failed SC coupler was the problem.  When the supercharger isn't turning, it blocks the air intake and the engine makes way less power than a naturally aspirated engine.  

You can pull the supercharger snout and change the coupler  yourself, but you're not going to change the bearing in the snout.  You'll have to send it off to ZZP or Intense Racing to have it rebuilt.  The rebuild process damages the original pulley most of the time, so don't do like me and have them put the old pulley back on.  Go ahead and upgrade to the modular pulley system unless you know you'll never want to mod the engine.  If you want to stay stock, have them put a new stock size pulley on.

If the tensioners are the same on series 1 as series 2, the front one is easy to change and the back one is more complicated because the coolant routes through it.  The rear tensioner is difficult enough to do that you might as well replace a few other things while you're in there, like the water pump, camshaft position sensor, and the heater hoses.  There's a couple plastic coolant elbows attached to the rear tensioner that should be upgraded to metal aftermarket elbows.  If you've never done the rear sparkplugs, they're easier to get at without the alternator and rear tensioner in the way.  Also, the engine 02 sensor, if you can manage to break it loose at all.  

This is a lot of work and it's best if you have a garage to work in and can have the car down for however long it takes.  For me, it can be a month or more while I ask questions on the forum and work through all the incorrect parts that tend to turn up.

Sorry if that's a bummer, but it can be done!  As a n00b mechanic I've put ridiculous amounts of time into this car, because I am inexperienced (well, not so much anymore!), but she's 24 years old now and still runs and performs like a new 97.  

Thanks for the reply!
So, if the reason for loss of power is the SC coupler - then it must be completely destroyed to have the air intake completely shut...
It is also possible that the noise is not directly connected to the loss of power...

The car has 168kilometeres, a little over 100k miles...
I don’t want to touch the tensioners if I don’t have to... If the replacement of the coupler fixes this noise - I will leave them, because I would rather do all of that work when I’m ready for more unexpected expenses...
I have replaced both crank and cam sensors down there about 2k miles ago...
All 6 spark plugs about 2 years and 4k miles ago, but I might check if they are good by disconnecting them one by one.
I think the water pump has also been replaced and in any case it isn’t showing any signs of failure yet...
Replaced harmonic balancer and idler pulleys at around 70K miles.
I have done tons of other Stuff on her and will do my best to bring her back to life and running well - not sure if I can manage making it run like in 95, because I am in Georgia the country and it is a PIA getting parts for the Rivie...

The supercharger coupling is your prime suspect, and it's only a $12 U.S. part. I'd undo the supercharger belt, twist the SC pulley back and forth, and see if you can feel any obvious problems. I don't know what it feels like myself. When I pulled my snout off to have the bearing replaced, the coupling was like new. The previous owner may have already replaced it.

If you didn't have to drain and replace the supercharger oil, this would be a simple job. The only trick is breaking the snout free once you get the bolts off. I used a crowbar to gently break it loose.

You can go ahead and replace the front tensioner. That one is easy to do. If you've still got the plastic elbows on the rear tensioner, make the upgrade to metal ones a priority. Mine were solid, but they're known to fail. It's one of the few problems with the 3800.

Jack the R wrote:

The supercharger coupling is your prime suspect, and it's only a $12 U.S. part.  I'd undo the supercharger belt, twist the SC pulley back and forth, and see if you can feel any obvious problems.  I don't know what it feels like myself.  When I pulled my snout off to have the bearing replaced, the coupling was like new.  The previous owner may have already replaced it.  

If you didn't have to drain and replace the supercharger oil, this would be a simple job.  The only trick is breaking the snout free once you get the bolts off.  I used a crowbar to gently break it loose.  

You can go ahead and replace the front tensioner.  That one is easy to do.  If you've still got the plastic elbows on the rear tensioner, make the upgrade to metal ones a priority.  Mine were solid, but they're known to fail.  It's one of the few problems with the 3800.  

The parts are on their way and I will post another video once they are installed. Thank you for the heads up about the elbows!
Cheers

I hear mostly an exhaust leak. Remove the supercharger belt, and run the engine, Turn the supercharger by hand back and forth, coupler wear will be very evident.

Will an exhaust leak cause a power loss?

Jack the R wrote:

Will an exhaust leak cause a power loss?

Yes, it could mess with the O2 readings.  That video sounds like an engine running with a rotted pipe/cat/muffler.  All I hear is exhaust noise, never mind coupler noise.

LARRY70GS wrote:

I hear mostly an exhaust leak.  Remove the supercharger belt, and run the engine,  Turn the supercharger by hand back and forth, coupler wear will be very evident.

I did that this morning and there was a significant knock and play - so I am now 90% sure it is the coupler... I will change it with the oil and the tensioner that’s next to it. I doubt the loss of power is because of the exhaust, because the car ran great when I started it and then lost power half way from the mechanic   that changed engine oil...