QR25DE Precat and Butterfly Screw FAQ

[Valtyr]

Thank you SO much for posting this.

[bmartin807]

Yes, thanks A LOT. I only have one question, I have an '06 model. You said they changed the screws. So I just have the pre-cat issue to take care of then? I shouldn't worry about the butterfly screws, or should I? Thanks a lot.

[Dangling Fury]

I specifically remember seeing a pic of an '06 model that had revised butterfly screws, it looked like there as a washer attached to the head of the screw. It looks like they fixed the problem but of course I can't tell with 100% certainty, just to play it safe I would check them myself after say 30k miles.

[Dangling Fury]

Ok I found it, here's a pic by seasick over at the Vboard, it shows the butterfly screws in his '06 QR25DE:



I also read that at least one '05 owner reported that he did NOT have these revised screws, so it looks like Nissan only started putting these in the '06 models. As far as I can tell these new screws are available for purchase from the dealer and are likely included in the package they use for the Voluntary Service Bulletin.

[SE-Mark]

A couple more useful threads on butterfly screws

QR25DE Sentras (02-06+ SE-R / SE-R spec V)
1. Butterfly screw failure / i'm burning oil and my spark plug is mangled.
How to Loctite butterfly screws: http://www.b15sentra.net/forums/showthread.php?t=78320
My spark plug had dents in it: http://www.b15sentra.net/forums/showthread.php?t=51299 (this is one of the original ones)

[stewspecv]

Thanks Dangling Fury, that was a great read. This newby learned quite a bit!

[shift_cloudspec]

a lot of information! awesome write uP! AAA++++++!

[bmartin807]

Awesome. Thanks a lot. I need to get on the pre-cat and I'm straight. THANKS!

[freakythangz05]

OK. What if u get the aftermarquet header with the cat? Do you still have to mess with the sensors?

[Dangling Fury]

Originally Posted by freakythangz05

OK. What if u get the aftermarquet header with the cat? Do you still have to mess with the sensors?

The only header on the market with a precat is the Nismo header, however, there were at least two instances where the precat also failed, so don't get it.

[petyweestraw]

Not bad at all,thats why u r who u r...........

[vbspecv]

nice 2 pictures of my car in this thread (the cat and the missing butterfly screw). Do you want a picture of the mangled spark plug, I have that somewhere?

[Dangling Fury]

Originally Posted by vbspecv

nice 2 pictures of my car in this thread (the cat and the missing butterfly screw). Do you want a picture of the mangled spark plug, I have that somewhere?

Damn, both of those are your pics? I hope your car is doing ok...

Can I assume that you are ok with me using your pics in this sticky? Don't worry about the spark plug pic, I think the missing screw one is enough to make QR owners sick to their stomach.

[vbspecv]

I have no problems with you using them
I lost the butterfly screw around 25,000 miles?
I was hoping the engine would blow up before warranty was over, no such luck. So at 60k I loctited all the butterfly screws and replaced the exhaust manifold and thats when those pictures were taken.

It has 70k on it now, compression was normal last I checked.
It does burn 1 quart of oil every 3,000 miles, but it has done that since the day I bought it. I ran it at Pocono during the Convention this year and it still seems to be fine.

Taking bets on how long the head gasket has!

[ibaaramu]

What are the tools required to take off the manifold? never did this before and kinda afraid i might screw up..