So today was my first day of really driving the S after the turbo install.

Everything ran perfectly fine, on the way home though I noticed when I engine brake (let off the gas while in gear) I was getting a nasty rattling sound. It seems to happen when I'm in 5th and let off. It doesn't seem to happen during acceleration or in the lower gears (unless I can't hear it). It's very difficult to tell where it's coming from.

Things that come to mind, wondering if anyone else has any thoughts:

1) Could under engine braking at this particular resonance the turbo be hitting the frame? Does the engine shift more under braking? (Logic says yes but honestly, I've been standing in 100 degree temps for over 8 hours now )

2) Exhaust hitting under the car somewhere? Perhaps one of the sides?

3) Something wrong inside the tranny? I'm thinking this is one of the least likely scenarios as it seems to shift and drive just fine.

If I had to pick anything, I'd say #1 is the most likely but I'm hoping to go not. I have the SC6076R.

Any help/opinions welcome!

 

Sounds like it could be a number of things. Please post some more informaiton on when the sound starts and stops what part of the motor area it is coming from
are the windows up or down when you hear it?
It could be something as simple as the compressor housing hitting the frame rail to valves needing adjusted.

 

Well, my windows were up. I need to go drive it again I think to tell you when it starts and stops. I'll go put the top down and drive around to see if I can give any better info.

 

So I went out and ran it, it's just very hard to tell. Seems most prominent in 5th and 6th under engine braking between 3000-2000 rpm.

I am wondering though if I did this. I need to wait for these storms to pass by. Yesterday I added that Supra PCV valve inline of the stock one. I put it flowing the right way. But when I went to check the setup, I was able to pull the hose right off the coupler. I'm wondering if it was tight enough and that caused some kind of issue. I also noticed some oil built up in there too.

For now, I went back to just a line and the stock valve and removed the supra pcv.

 

what clutch do you have?

 

ACT 6 puck competition

 

How close is your dump tube to the frame?

 

That has a decent cushion, like at least 2-3". The turbo is much closer.

I need to drive it before I speculate if this is still happening. I'm thinking because the coupler I used on the Supra PVC I put in was a hair too small, that perhaps the tubing was leaking air when the crank case was venting and it was making this sound.

Around lunch I'll take it out and post up again if it's still going on.

 

Definitely nothing to do with PCV. I think it's something under the shifter area. I'm going to have to get under there.

 

well on my car when the revs are falling between 3500 to 2000 i get some buzzing and i know its my clutch so that could be your problem