2000 ssei clatter with low boost.

[LAIDBACKLUKE]

So my car has been producing a little clatter usually when I'm going up hill, and usually right before the trans downshifts.... I was wondering if this could be the Supercharger bushing? not sure if thats what it scalled, but the bushing in between the pulley/snout and the impellors? thanks.

[00Beast]

It's called the coupler. Easy way to check it is to loosen the belt, I believe the tensioner is a T50 torx, then spin the pulley back and forth with your hand. If it clunks, it's bad. However, it normally only makes noise at idle. This sounds more like a misfire. When was the last time you did plugs and wires? On my car I have to do plugs once a year otherwise they go to hell on me.

[LAIDBACKLUKE]

I did the wires about a year ago.. plugs at about the same time, I getting ready to put some autolite103s in it, I guess we'll see if the plugs are the problem. Thanks for the reply.

[RJolly87]

What octane gas do you use?

[LAIDBACKLUKE]

I use 89, but put Gumout octane boost in every fillup...

[RJolly87]

It would be better if you use premium every fillup. Try it for a few tanks. See if the issue improves.

[willwren]

Your car requires PREMIUM fuel 91 octane or higher AT ALL TIMES. Your mileage will improve, fuel costs will go down, and you'll stop damaging your motor. Gumout octane boost does nothing to raise the octane. It's raising your 89 octane to 89.1 at best.

ONE POINT of octane boost is 0.1 octane. POINT ONE. You're killing your car. It says PREMIUM UNLEADED FUEL ONLY for a reason. I can't stress this enough. I've seen the results of repeated knock on the pistons first-hand on several occasions during engine autopsies.



Supercharger couplers only rattle at idle when they get worn. I suspect you have massive knock due to the low octane, and I bet your pistons would show it if the motor was torn down.

[00Beast]

What mods do you have that you would go to 103's? I run 104's and I'm on the upper edge of using those with my mods. Colder plugs do nothing unless you're using them to support other mods.

[Archon]

I agree with all of the above, and will add that too cold of plug will foul too quickly. Another thing to check is your cat., if the rattle seems to come from under the car.

[00Beast]

[LAIDBACKLUKE]

I've have the cat replaced with a highflow cat, deleted the resonator, flowmasters at the rear, I'm getting ready to go to a 3.4" pulley also... K&N large cone filter. I'll do the 91 octane and see what happens... Thanks.

[myfirstbonnie]

I would not go any farther with the pulley until you start running premium, scan for KR and get the noise taken care of. The pulley will just add to the problem right now.

[willwren]

You may have already damaged the motor. Do NOT change that pulley. Buy a scantool or scangauge instead. You need it at this point.

[00Beast]

That isn't even close to enough mods to justify 103's. Put in Autolite 605's and run premium only. It doesn't say "Premium Fuel Optional" on the gas door, it says "Premium Fuel ONLY".

[02ssei]

I agree with myfirstbonnie and willwren. Figure out the noise first and start scanning before the smaller pulley.

[00Beast]

The clattering could be audible knock....

[willwren]

That's what I'm thinking. And at this point, I strongly suspect the pistons are pretty well eroded in the ring grooves at the very least.

[01bonneSC]

I use 89,

Seems we have WAAAYY too many members trying to do this as of recent. Its only, like what $4 more/tank premium compared to regular? And I bet the octane boost is about that much for a bottle, which doesnt do anything anyway.

[00Beast]

That Gumout is probably $6 a bottle, and does nothing except lure you into thinking you are safe, when you are in reality doing more damage and spending more money.

[Bonnefied_GM]

I still don't understand how people get to using the wrong octane in premium-demanding cars (unless they're just the average Joe who thinks gas is gas and premium is a marketing scheme or power-adder). I looked at a '92 SSEi once with low miles and a clean exterior/interior, but after hearing an audible clatter/knock and discovering the twit of a salesman using ethanol-blended 89, I knew it wasn't worth looking at any longer since I don't want to deal with major motor work.

But yeah, using regular in an L67 (any series) is NEVER good and can only hurt it over time (and that gets worse and worse as it goes). If your noise is in fact a knock, you can bet it'll only deteriorate. But yes, change over to premium IMMEDIATELY and really get some readings. Your motor is due for a good looking-over on such grounds. And of course, check for other sources of the rattle such as heat shields, etc.