Mledbetter

I hope it's just the bypass valve. If you need a new one, I've been happy with the Lindsey unit.

It's a nice car... It's worth spending 80 bucks to throw it on the dyno with a wideband to see what the a/f ratio looks like.

good luck!

-Matt

Luke

how much boost and what chips?

badass951

14 psi at max, but I usually run 13 psi. Also, I use a chip from Promotion Racing (a 944 specialist in Miami).

badass951

To add to the description. The sound is like a fluttery/metallic sound as I have described before in this post, however, it is very loud. When I release the gas and press the clutch to shift at full boost, I hear the bypass valve flutter even when I am inside the cabin of the car...does anyone else hear this inside their 951?

Also, under hard acceleration (I would say from 4500 rpm and up), I hear what sounds like sparks bouncing off the walls of something metal like a pipe. This rarely happens. If it does, and it is dark outside however, I can see the light underneath the hood (from my driver position) flicker. Another 951 owner has been in the car with me when this happens, and is positive the sound it makes is normal, however why would it make that light (or if it is something else) flicker?

Mledbetter

I have the Lindsey valve and you can hear it from 50 feet easy... That part sounds normal. If yours is holding boost and releasing on shifts, it sounds like its working fine.

You can actually see a light under the hood? Try (when its dark) popping the hood and running it up to 5 or 6 grand (while parked, just in case thats not obvious). Maybe your plug wires are bad and its actually jumping to something metal. You would be able to see it easily.

So, far everything you mention leads me to think its detonation, but checking the spark is free and painless.

-Matt

Ahmet

Remove the underhood bulb, repeat the test...
Ahmet

badass951

Thanks mledbetter. I was going to take the plugs out anyway, as I was told this could be causing a misfire and leading to the smoke coming from my exhaust. At this point I have heard so much, but like you said, checking the plugs is free and should tell me something valuable.

Could bad spark plugs be causing my problems?

Mledbetter

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by badass951:
<strong>Thanks mledbetter. I was going to take the plugs out anyway, as I was told this could be causing a misfire and leading to the smoke coming from my exhaust. At this point I have heard so much, but like you said, checking the plugs is free and should tell me something valuable.

Could bad spark plugs be causing my problems?</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Actually I was talking about the plug WIRES. If you hear something that sounds like spark and you can see light under the hood, just rev it up while it's dark. Should be easy to see with your head under the hood.

-Matt

badass951

I guess you were, but since I was already thinking to myself to simply check the spark plugs I just read it that way to myself. But the reason I also assumed you weren't talking about the wires was because the firewall behind the engine compartment cuts off anything you could see from inside the car; it is a safety precaution. That is why I am assuming since it is a flickering light I see, that is the light under the hood, which is between the car and the firewall.

Ahmet

Hello, disconnect the underhood light...
Ahmet

badass951

Hahaha, I know, but I am assuming this will just make the light flickering go away. I am more concerned with the sound that accompanies it, but I guess there is a chance both the flicker and sound would go away if I did.

Ahmet

I say this because I've had the underhood light of my turbo come on under hard acceleration before. I assume hard acceleration has the same effect as an open hood on the light. A very easy way to find out, as I said would be to remove the bulb, or you could turn off your lights when it's happenning and see if it still flickers.
Ahmet

badass951

That is actually great to hear.

Perry 951

Ok.. the metallic turkey gobbler is a bad BOV, or to be correct, recirc valve. Remove yours and look at the outlet. I bet the rubber surround is torn.

For the light... 99.9% sure it is the curtosy light in the engine bay. With the *** end squatting, the switch can be enabled.

If you would like to replace the BOV with the 996 unit, I have one with 3000 miles on it. $10 and it is yours. Check the rubber seal first.

Mledbetter

I just watched the video and I think we are talking about 2 different sounds. You are talking about the fluttering when you shift gears at the 3 second mark. The detonation sound is at the 5 second mark.

-Matt