Ok, so I just replaced a lot of items. I have the same sanding/grinding noise, as well as a crackling noise when under a heavy load.

Items replaced:
-clutch master cylinder
-clutch disk
-pressure plate
-flywheel
-pilot bearing
-torque tube input shaft bearing
-torque tube couplers
-rebuilt transmission

When Im in gear under a heavy acceleration/higher rpm, I hear a noise that I'm not sure what it is. Not sure if exhaust leak or bearing or what exactly. At first I thought maybe ignition? Timing? Wires and plugs have been replaced, not sure on coils. Car has 150k.

Update: after speaking to a friend, we think it is predetonation. I just filled up the car so I'm going to baby it till the next fill up and put race gas in it since the highest octane in CA is 91 and this car is not from CA. Trying to see if I can find a tuner here but if anyone thinks its something else please let me know thank you.

 

Anybody have an idea as to what this is? Maybe this should be in the general area?

 

wWow that is weird i listened to that at least 20 times. It kind of sounds like detonation. Have you changed gas stations?? Someone on here had some detonation and put 3gals of e85 when filling the tank up and has stopped. Maybe give that a try. It's not going to hurt anything and something simple to do.

 

I've tried different gas stations, I tried octane booster, fuel injector cleaner, etc. Nothin. I was trying to find unleaded race fuel but all I can find is leaded. Hmm, maybe I should try the e85. Here in CA, all we have for premium is 91, not 93. And since the car is from CO, I don't think its too happy. I'm curious to know if maybe knock sensors just arent doing anything. But I'm not sure how to check that. I did pill a spark plug from each side and they both looked good. Nothing tore up. I'm running NGK TR55's. I'm not sure what to do next. I'll try that e85 thing as thats better than nothing!

 

why is the cel on?

 

Seconday air injection system. I need to figure that out real soon if I want to pass Cali emissions. Seperate story, but that fuse was blown, so I bought new pump, replaced fuse, fuse blew again. In the fuse box where the fuse plugs into the contacts, the plastic near those connectors is melted, which means someone must have put waaaay too big of a fuse in there and I'm afraid the wires are gonna be toast.

 

Octane booster is garbage. It's not enough to make a difference. E85 is 105 oct and your putting in 3gals not 10 oz or whatever it is.

 

E85 is harmful to the car though isn't it? Fuel system isnt really rated for it? You need different seals right? If I were to try this, is it like 3 gallons and then fill up with normal premium?

 

So, I may or may not be a firm believer in Amsoil now. I ordered their 5w30 signature series motor oil, their ATF trans fluid, and their 75w90 severe gear oil. All installed today. When I replaced the trans last week, I put standard valvolin dex/merc in and royal purple 75w90.

*Disclaimer, I put seafoam in the motor oil before changing the motor oil. Not sure if this helped or not*

So, here's whats weird. Before with mobil 1, I thought maybe my oil was on the lower pressure side. Now with this Amsoil, I've noticed a huuuuge pressure increase. Both at idle, and at WOT. I got the car up to temp and it sounds A LOT better. Tomorrow when I get to take it out on the highway I will see how it really does.

But that's what scares me. I used mobil 1 5w30 just like a bunch of others run. I've always liked mobil 1. Now I switch to a different sythetic 5w30 and all of a sudden it's better? Maybe Amsoil really is a better oil, I'm not sure, I'm not a scientist. All I know is my crackling noise seems to have gone away, which makes me think that noise I was hearing is a starving oil pump. Which is where I start to get nervous. Let's say this noise was the oil pump. Shouldn't a CEL have been triggered? Is this a sign of the oil pump on it's way out? Any and all advice is appreciated. I just don't have the time to tear back into the beast again until 9 months down the road when school is done.

Thanks for reading this.