Blown Air Box!!

I took my car in this morning due to backfiring in the morning during cold start. Earlier many of the folks here diagnosed the problem as a faulty warm up valve. It turned out that I have crack in the air box despite the pop of valve. The WUR was okay upon pressure testing. I am the guy who lost the throtle elver and relies on the steady foot (a lesson for all those i nthe same situation). My mechanic says four hours to R&R the box!! I must admit I do have a recessive gene in mechanical aptitude but could possibly tackle this one with some good direction, Is it a tough job gents or can I mess up more then I bargained for? Any info on aftermarket boxes or stick with OEM?
HELP!!!!!!! and thank you.

Bob
1973 911T

Check the tech article section on this website. There is an article about installing an air box pop off valve. This includes (I think) removing the air box. It doesn't seem that hard if I recall.
Rich

No, it is not necessary to remove the air box in order to install the popoff. I believe a right-angle drill is needed though, or an attachment. My attachment cost $20.

but I think your question has to do with R&Ring the air box. I took the air box off mine but the motor was out. I would HATE to try and do this wiht the eingine in the car.

Oh, I noticed that your car is a '73 nevermind.

But FWIW, I need to replace my oil thermostat o-ring, according to my most excellent buddies here. And I plan to remove the engine to do it, because of this air box.

And I'd be very leery of aftermarket parts on my car, period. German car parts gang up on newcomers that are not also Germans. This goes for VW as well.

------------------
'83 SC

Surprising to see that what the pop off valve was designed to prevent is still happening.

If this is the case, then this scenario will most lilely be repeated sometime in the future even with a new pop off installed in your new air box, right?

I had a 74 911 with the same nightmare of a problem. I finally eliminated the exploding airbox problem by installing the updated 81 style box with the internal cold start plumbing and 76 aux air reg etc.

With this setup in place, I never had another explosive mishap even without installing a pop off valve.

If there was some way to install the same setup on your 73, airbox problems would be a thing of the past as it has been in my case.

Sorry for the long post, but you got me thinking...

Cheers,

Joe Garcia
86 Carrera

I wonder if the pop off valve was installed correctly.
It is pretty difficult to blow the box with the pop off installed correctly, although I guess anything is possible.
But if the valve opens properly, its hard to see how enough pressure could get built up in the box to blow it.
Sometimes people don't fully understand how the valve works, what it is designed to do/prevent, and how it should be installed. If the previous owner installed it or had it installed incorrectly, that may have been the problem.
I don't think 4 hours is unreasonable to charge to replace the airbox. Belive me, it would be hard to do it in much less time that that!!