3.2 Intake manifold bolt torque

01sport · 03-01-2007, 12:08 PM

87 Carrera 40k. I recently spoke with a Porsche wrench who said I should check and torque my intake manifold bolts. After a search I have learned the torque value is 18ftlb, 8mm hex. Blue locktight and spring wave lockwashers were also mentioned as were removal of heater parts and air box. Looked for a proceedure but have not been able to find one.

Any tips or opinions on locktight, lockwashers, sequence of bolt tightening, specific tools needed or access to bolts would be most appreciated.

Suppose I could only get to some of the bolts before I needed to get additional tools. Should I avoid driving the car until all the bolts were tightened?

TIA
Jeff
(newbie)

01sport · 03-01-2007, 06:20 PM

Anyone have to do this to a 3.2 in the car?
Is it a 1 or a 2 bandaid job?

rick-l · 03-01-2007, 08:02 PM

I took the intake off my 88 to replace a fuel hose. Don't remember any lock-tite or lock washers. I think there is a washer and a (barrel?) nut. Should be pretty straightforward. The heater duct and air cleaner are easy to remove.

Be sure you replace all the vacuum hoses you knock off

Do you have a rough idle?

01sport · 06:11 AM

Hi Rick,

Thanks for the reply. My idle cycles between 750 and 800 rpm every second of two. It is a little rough. I have noticed that the idle sort of thumps. You can feel the car bouncing around in the seat of your pants. Perhaps related to manifold? Do you recall tightening to the full 18ftlb / 25mn?

Which fuel line were you replacing?

Sounds like this may be a good time for me to replace the sound pad as well. Any other "while your in there" jobs I should consider?

Jeff

syncroid · 03-02-2007, 06:24 AM

Hi Jeff, At the shop I work at, torqueing the intake manifolds is part of our standard service. 18 foot pounds is correct. I remove the air flow meter and filter housing. I also remove the "s" shaped heater hose on the left side of the motor. Tools; torque wrench, approx. 10" 3/8 extension, universal adaptor, and a 8mm allen socket. The most difficult barral nuts to access are #3 and #1. (The wires from the head temp. and speed/reference sensors get in the way for #3 and the fuel line and ground wires get in the way on #1. I think Rick is refering to the main engine fuel line. The original ones had a tendency to leak in the center where they are joined to the metal pipe.

KTL · 03-02-2007, 09:33 AM

syncroid is right on. You need to get a few things out of the way to get at the barrel nuts.

Blue loctite and spring washers (i'd pick wave/crinkle vs. split in this case) are not a bad idea. What also helps is to use a hex key with a ball-end on it. I cut the bend of a ball-end key and put it in a 8mm socket to make a tool for tightening the nuts.

Other places to check for leaks are the vaccuum hoses at the rear of the throttle body (they attach to what I believe is a thermo switch) and the brake booster hose assembly on the driver side forward end of the engine.

01sport · 03-02-2007, 02:09 PM

Thanks for all the advise guys. Exactly the type of Pelican help I was for looking for. I decided not to use Locktite (if this is a routine job and people are not using locktite already there must be a good reason). I do want to replace the washers with wave washers but I'm not sure of the size. Socket Cap Screws with 8mm heads are M10 in the McMaster-Carr catalog. Pelican does not specify thread size. Anyone know what the 8mm Barrel Nut thread size is?

Don't mean to make such a big deal about such a routine job.

I just don't want to get stuck and not be to drive my car.

syncroid · 03-02-2007, 02:19 PM

The thread size is 8 x 1.25mm

01sport · 03-02-2007, 02:20 PM

Thanks, Have a great weekend