Greetings,

Purchased a bone stock VIII with 173k back in October. Car now has over 176k. Has been running just fine until a few days ago. This started after I wired and installed a COP setup. I'm admittedly having troubles with the pins staying in the coil connectors but the car is not misfiring or anything noticeable among those lines.

Whenever I hit 5500rpms, the car starts to make a screeching noise. That's the best I can explain it. Only happens at 5500rpm, haven't taken it any further than that since it started happening. Anything below 5.5k is fine. Spools fine, don't seem to notice a lack in power.

Sorry if this post is kind of vague. This is my DD and I'm starting to order parts for it so I just want to make sure nothing major is happening before I start modding. I'm still waiting on my tactrix cable from New Zealand so I can't start logging yet. Still waiting to get a boost gauge installed as well. I will try my best to get a video up tonight or tomorrow.

Should I go back to the OEM ignition setup and see if it persists? I didn't know if that would even be a possibility for this issue. Other research says possible turbo going out, but wouldn't I be noticing loss of power and issues before 5500rpms? Kind of sounds like it might be turbine blades/fins possibly scraping but would expect to hear it sooner? T

 

Welcome aboard & thanks for posting

Why dont you pull the inlet hose to the turbo & check the play w/the wheel?

176K miles is well up there & any component failure is possible after that length of duty

 

doesnt sound like an ignition issue.
probably just a coincidence

^^^like he said... check the turbo.

 

when referring to 5500 rpm - are we taking loaded i.e. driving or stationary in Neutral? I would guess boost pressures / turbine wheel speeds for both those scenarios would be quite different.

Also sure its coming from under the hood? I have heard fuel pumps screech at times.

pulleys and accessory belts can do that too... check the easy ones first and then start pulling things off.

 

Thanks for the replies. I managed to get a few videos on my way home from work. I should have time tomorrow to pop the intake off and check for shaftplay before I have to drive it again.

The first video you can faintly hear what I'm talking about in my initial post right in the beginning of the video. It went away once I got past 6000 or so.

The second video is driving through my neighborhood in 1st gear only. It starts to make a noise around 4500rpm this time. Same thing with third video around same rpm range.

 

I have the car apart right now. There's no shaftplay, turbine seems fine. Only thing was some oil inside the intake tube, MAF, etc. which I'll clean up. Going to install my IX MR bov while I've got it apart.

I'm probably going to go ahead and go back to oem ignition before I drive back to work today just for good measure.

One more thing I noticed though... my upper radiator hose was oddly pinched? Like it wasn't a round hose.. it was just squeezed. I opened the radiator cap and some pressure let out, I was able to unpinch it a little bit. I'm probably just going to go ahead and try to change that hose and thermostat this weekend but any thoughts on what could have caused that?

 

Thanks for the update. Keep us posted on what is eventually found or if you have other questions. Diagnosing over the Internets is tough

Again, great to have you on the EvOM boards

 

if you just rev it up with the car stationary, do you have any noise coming from the cam gear side of the motor?

sound may be bearing on cam chain tensioner or acc belt tensioner