My intake manifold hates me

therotman · 09:53 PM

why can I not get #5 off? I can not pull it up enough to clear the studs.

Do I need to disconnect something else? This is an 1980 sc.

JohnJL · 08-07-2008, 10:28 PM

Try loosening up the clamp to the manifold, and squirt some wd40 down by the gasket. You should be able to "wiggle" the aluminum manifold then.

therotman · 08-07-2008, 10:47 PM

The clamps on the rubber intake sleeve are completely loose and the manifold pulls up easily from the rest of the engine.

The airbox just seems to be in the way of me pulling it up far enough to get it past the studs?

911pcars · 08-07-2008, 11:24 PM

Just a thought. Unless something else is in the way, you can temporarily remove the engine mount bolts and lower the engine about 1mm more than the length of the studs. However, the engine mount bolts may have their own issues for easy removal due to corrosion and the lack of a counter-rotating hold while loosening each bolt.

Sherwood

therotman · 08-07-2008, 11:44 PM

Quote:

Originally Posted by 911pcars

Just a thought. Unless something else is in the way, you can temporarily remove the engine mount bolts and lower the engine about 1mm more than the length of the studs. However, the engine mount bolts may have their own issues for easy removal due to corrosion and the lack of a counter-rotating hold while loosening each bolt.

Sherwood

Isn't the airbox going to drop along with the engine if i do that? That is where I am having the clearance issue.

911pcars · 08-08-2008, 12:04 AM

Quote:

Originally Posted by therotman

Isn't the airbox going to drop along with the engine if i do that? That is where I am having the clearance issue.

Is the airbox clearance to the top of the engine compartment the issue? If so, lowering the engine slightly will increase the clearance slightly. Isn't the airbox connected to the intake manifold?

Sherwood

Wayne 962 · Wayne 962's Garage

Sherwood, the problem is with the clearance between the engine shroud and the bottom of the CIS box.

This job is a huge pain. I think you need to loosen the bracket at the back of the motor to allow the airbox to float up a bit. If you think getting them off is difficult, wait until you have to put them back on! You will need a super long screwdriver, and lots of patience.

-Wayne

safe · safe's Garage

Do you only need to remove no 5 runner? Otherwice remove the whole injectionsystem as a unit.
To do this lowering the rear engine mount an inch or two helps...

yelcab1 · 08-08-2008, 05:58 AM

I did say that a better mechanic than me can do this in the car. I really can't do this job in the car.

Peter Zimmermann · 08-08-2008, 07:11 AM

The CIS system really isn't designed to do repairs such as runner sleeve replacement. The reason that engine removal (or partial drop for you guys who have backs that can handle leaning into the engine compartment for hours) is required to do an SC airbox is that there are two brackets that fasten to the front of the airbox, and then to the top of the engine (one on #6 manifold, one on the throttle lever console). On cars with a correctly installed airbox those brackets must be disconnected before runner removal can be done, and if you can get them loose without an engine drop, you will not be able to get them back on correctly with the engine in the car.

therotman · 09:46 AM

Thanks for all the input everyone.

I already replaced the sleeves on 1-3 and #4 came out easy, but #5 happens to be the one with a huge hole that I believe to have made my engine stop running. #6 feels like it is still in good shape if it is not possible for me to replace it now.

The biggest problem I have with the partial drop is I have no floor jack! Should I just run out and buy what I have putting off for way too long or is there a way to loosen the CIS while the motor is still in the car? Is that what the bracket at the back on the engine would do for me if I loosened it?

911pcars · 08-08-2008, 10:35 AM

Quote:

Originally Posted by therotman

Thanks for all the input everyone.

I already replaced the sleeves on 1-3 and #4 came out easy, but #5 happens to be the one with a huge hole that I believe to have made my engine stop running. #6 feels like it is still in good shape if it is not possible for me to replace it now.

The biggest problem I have with the partial drop is I have no floor jack! Should I just run out and buy what I have putting off for way too long or is there a way to loosen the CIS while the motor is still in the car? Is that what the bracket at the back on the engine would do for me if I loosened it?

A jack to lower the engine a few inches doesn't have to be fancy nor of high capacity. A scissors jack on top of a stack of interlocking 2x10s would probably do it (a scissors jack becomes more unstable as it extends). The weight you're going to support isn't much.

If possible, I would aim to support the vehicle at the most comfortable working height, then go from there. However, anything is possible under less than ideal working conditions (e.g. most projects in a home workshop).

Sherwood