palsor1

iTrader: (2)

Hey guys,

I'm trying to diagnose a rattle noise my car has had since I got it. The noise is coming from the passenger side of the engine. I can hear it quietly from above the car, but I can hear it loudly from under the car. I used a piece of fuel line held up to my ear as a stethoscope, and I can hear the rattle most clearly when I put the end of the hose near the rear side of the front turbo.

After searching, it seems like a lot of people have rattle noises when one the three actuators gets loose so I started messing with the actuators. If I move the lowest one in, I get a new rattle at a different pitch, and if I let it out again, the new rattle goes away, so I think that actuator is fine. If I move the middle actuator, again I get a new rattle at a different pitch, but if I let the actuator out, the rattle goes away. Thus I think the middle actuator is fine.

If I pull the top most actuator in (I think this is the wastegate actuator), the rattle noise changes. It's hard for me to tell if the rattle noise that I'm searching for changes, or if this is a new rattle noise created by me pulling in the actuator, similar to the previous two actuators. It's hard for me to tell because the pitch is the same.

Has anyone else had their wastegate spring or actuator go bad? Or rather, I'm sure people have... has anyone had it go bad and cause a rattle?

Also, does anyone have any other ideas of things to look for near the rear side of the front turbo?

- Andy

palsor1

iTrader: (2)

Some other notes:
- I only really hear the noise at idle. Once I get above 1400 or 1500 rpms, I can't hear it anymore, although that could just be the engine noise drowning it out.
- My idle is a little high at about 1100 rpms, but other than that is fine. It doesn't hunt at all.
- My boost pattern is also pretty good. It goes 10-8-10, but on the second turbo it hunts a little bit. By that I mean the pattern will actually look like 10-8-10-8-10-8-10.
- Mods are exhaust, DP, intake, and hose job. Still have stock cat.

palsor1

iTrader: (2)

Bump - any ideas?

ArcWelder

Loose heat shield possibly.

dgeesaman

iTrader: (7)

You should try disconnecting the actuator arms and checking to see that they are properly adjusted.
https://www.rx7club.com/forum/showth...hreadid=169138

Dave

dgeesaman

iTrader: (7)

You should try disconnecting the actuator arms and checking to see that they are properly adjusted.
https://www.rx7club.com/forum/showth...hreadid=169138

Dave

palsor1

iTrader: (2)

Dgeesaman, I'll try that. Thanks!

I also did some more looking tonight, and found that one of the bolts that holds the front turbo to the exhaust manifold is missing. Even better, it seems that the rattle noise is centered around the missing bolt hole. There are three bolts that bolt the turbo to the manifold, two on one side of the turbo, one one the other side. The one that's missing is the one that's by itself on one side.

Could that missing bolt be causing this rattle? Either way, I'm going to be putting a bolt in there. It can't be good to have it missing.