intake runner boots/drop?

[Mike Kast]

I adjusted the valves a few weeks ago, changed plugs, oil, cap and rotor, yadda yadda... The car slowly started to deteriorate soon after. It was cold starting funny and acting just a little bit off.
I started thinking pretty quickly I screwed something up.
Plugs gapped wrong? A cracked plug maybe?
I was talking to a buddy about it, well, really a hired buddy, He works for my mechanic. So, that makes him a mechanic.
My van broke down Monday so I had it towed over there and asked him about my plug problem. I forget exactly what he said but he led me to believe he was thinking I had an air leak.
I said "AIR LEAK!" with fear in my voice I'm sure...
He said "I don't know" trying to let me down easy
Once I got back home from the mechanic without a van it occurred to me I had been blessed with a day off to drive my 911 to the shop and talk to my manager about my game plan. I had already sort of decided to find another truck.
I did that, and on the way home right about the same place my clutch peddle broke in half this spring. The car stalled
I started it up and got to the next light and she stalls again uhggg I start it up and she moves along but now she lets out a backfire with a black puff of smoke. What a beautiful day!
Tonight I took all those damn plugs out. They were gapped a little tight and number 4 was really black. I was hopeful. Start her up... stall and repeat...
I started examining for air leaks and low and behold number 5 has a huge hole in the boot. Is it possible to replace that one without dropping the motor?

Did anyone read all that crap?

[911Mac]

It can be done with the engine in the car but it's a PIA. Dropping the engine will give you alot more room to manuver.

I'm not sure you'll be able to get the left side intake manifold off without at least loosening the airbox. There's a bracket at the left rear anchoring the airbox that is bolted to the throttle bell-crank, loosening it may allow you to pull the intake off. Getting to the clamps around the boot(s) may be interesting.

Are you going to replace all the boots? If one is bad the others may not be far behind.

Good luck!

-Mac

[Mike Kast]

thanks Mac,
You know the deal, if I have to do a drop there is a load of stuff I'll need to attend to. Minor oil leaks and the like. I'll have to replace all the boots within the next year but I'd like to get throught the summer.
The drop will be a nice winter project if I can get through the summer and fall.
The one with the hole is center right. I don't know if that matters but I think it might. I unbolted it last night and it seemed like if I could cut the rest of the boot with a razor or something the manifold might have the room to lift off the studs.
Then there may be enough room to work on the clamps.

I just want the fall! That will give me the time to work up the courage and brain power to drop the engine.
I know how I operate. If I drop the engine the car will be down for 3 months. Everything will need to be powder coated and detailed and better than new.
And I just paid too much for another van.

[bkcbuilder]

I did the airbox change-out 3 weeks ago. I dropped the engine, and it was a total PIA to change it with the engine out. The screws on the clamps to the rubber boots were only accessible from the front of the engine. The intake tubes have machined collars that prevent the boot from being slid further onto the intake then slid over the airbox later, the wur is in the way of the bolts, I mean it's a total cluster in there to get to anything. If I was 2" tall and had hercules strength I MAY be able to pull it off.

I REALLY would like for someone to describe in detail how this can be done with the engine in the car.

For the 30 min. it takes to free the engine from the car, I really can't see why someone would go thru the knuckle scrapping, back aching contortions to get to those intake tubes.

I failed to change my rubber collars at the time of the airbox change...they were good, but I can tell they will need it in the future... DOH!

[Mike Kast]

30 minutes?
Back up... if your telling me I can't get to center right without removing the box then I will have to drop the engine. Is that what your saying?

I have to buy the boots anyway, maybe looking at them will give me a better idea of whats in store

[bkcbuilder]

Center right is the lowest and most covered one correct? The airbox is fully over it, you cannot lift up on it to get the intake tube off the head studs, becaus the #4 and #6 are in interference with it, and you have the aux air valve in between it and #6. I think you MAY be able to get to #1 or #4 without an engine drop...but not me.
30 min. is pretty easy. Gearwrench flex head wrenches are the best thing ever invented(besides 911's)

[Scott R]

I did this "in-car" and regretted it, but it can be done. You need to remove the AC compressor, then the first intake runner on the right needs to come out, which means you also should remove the fuel injector for clearance. Then you can access the clamps for the middle runner.

Five hours later I had all of the boots replaced, then a week later due to other issues I dropped the engine anyway. Figure it would take 10min to remove the entire CIS system with the motor out, flip it over and replace the boots.

[bkcbuilder]

Get a flashlight out, check where you are going, see which direction the screw heads for the clamps are going, look at the aux air valve...think it through and then remember most of this stuff does'nt flex without cracking as you think. Pry up on the top of the airbox and it may split($310). You have some time... think it thru.

[Mike Kast]

The long and short of it is it can be done. Is it the right way to do it? NO!
It is a lot of stress on the air box but all is well. I must have been screwing around for 4 hours. but I still can't imagine being able to drop the engine and fix things and put it back in less than a long weekend. Thats just for me. I'm no speedy mechanic. I'm disorganized.
my 911 lives!

[Dave Taylor]

A friend of mine did a quick fix with duct tape and it's lasted more than 2 years now. Someday he'll drop the engine and do it right, but at least he's been able to drive it all this time.