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Head Removal

 
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emoore924  



Joined: 13 Apr 2004
Posts: 2815

PostPosted: Wed Dec 14, 2011 12:17 am    Post subject: Head Removal Reply with quote

Difficulty: 7 out of 10
Time: removal only, 2-3 hours depending on skill and rusty-bolt problems you might encounter. Time does not include reassembly.
Warning: Do not attempt without the proper tools or you might get stuck
Warning: this procedure assumes you label and catalog the removed parts for later assembly

WARNING: This writeup is no substitute for a Manual. Stop cheaping out and go buy a Haynes manual. They cover this topic fairly well, and way better than me, being the pros that they are.

0) disconnect battery
1) Mark then remove vacuum hoses from acumulator.
2) Remove air intake stuff:
2a) Remove hose with hose clamp from air intake
2b) Remove 10mm bolt that holds intake hose to TB. Return bolt to TB so you can find it later.
2c) Remove hose from aux air reg
2d) Remove intake pipe
3) Remove auxillary stuff from intake and head:
3a) take off 2 6mm hex bolts holding bracket to LF of head
3b) label injectors 1,2,3,4 w/1 at front, remove from head
3c) remove vacuum hose from front of TB
3d) remove vacuum hoses from TB to dist (two of them, label them)
3e) remove banjo fitting from fuel line at back of TB
3f) remove bolts from TB bracket to block
3g) remove plug wires. number as you did the injector lines
3h) remove aux air reg -- put mount bolts back on intake manifold note: might need to move aux air reg to get to intake mount bolts
3i) remove bolts/nuts that hold intake manifold to head, remove. note: keep track of where brackets and ground strap go
4) drain coolant
5) remove top of t-stat housing (coolant hose attached)
6) remove distributor (13mm)
7) remove 2 coolant hoses at rear of head
remove 2 wires at rear of head from oil pressure and temp sensors (carefully). Its a bit fiddly in there so take your time. 1 wire is a slip-on bayonet and the other is a tiny-tiny nut on stud. Don't just yank on it or you'll be sad.
Pick either 9-1 or 9-2
9-1) remove nuts from exhaust manny and draw the manny away from the head. When you ge the manny away from the head, you might need to support the exhaust from beneath the car so you don't stress the hangers.
9-2) An alternative is to remove the nuts connecting the manny to the downpipe and allow the exhaust manny to come out with the head. After all, there are only 3 little nuts. How hard could it be Pick your poison I say.
11a) Set motor to TDC
11b) Remove water pump pulley
11c) Remove cam belt
11d) remove valve cover
11e) Remove head bolts. There are 10. May require a special 12 triple-square. DO NOT ATTEMPT REMOVAL OF THE HEAD BOLTS WITHOUT THE PROPER TOOL. Also, be absolutely certain that you have the tool fully seated in the bolt head before you start cranking on it. There will be oil in there and there may be metal particles or dirt in the bottom of the bolt head that you need to clean out before inserting the tool. Remove the bolts in a progressive cross pattern. So if they're labeled 10-4-2-6-8 ax the top and 7-5-1-3-9 ax the bottom, you break them loose highest to lowest, then go 1/4 turn at a time and you loosen in order highest to lowest, then repeat until they're finger-loose. Note, installation is progressive as well. See note below.
12) Remove head. May take a tap or two to the side from a RUBBER hammer to break seal. SET ON ITS SIDE AS THE CAM IS STILL IN AND YOU CAN BEND VALVES IF YOU SET IT DOWN FLAT.

There is all kinds of stuff you can do from here. Remove cam, valves, refit head, replace gasket, yadda. But you're on your own for all that. And fair warning, you don't just slap a new head gasket back on and reassemble. You need to have the head checked for straightness and the block mating surface should be cleaned up before reassembly.

Oh, and as they say in Chilton land "Installation is the reverse of removal".

SPECIAL NOTE: When replacing the head, installing the bolts is progressive, meaning, you torque them in a series of 3 steps, the last being the final torque setting. So here's how you do it.
1) Install head onto block with new gasket. Use the little centering collars to locate the proper spot. DO NOT SLIDE THE HEAD AROUND TRYING TO LOCATE IT OR YOU RISK DAMAGING THE HEAD, BLOCK OR NEW GASKET.
2) Intsert your NEW head bolts and tighten finger tight. (C'mon. They're like 2 bucks each. Don't cheap out an reuse your old bolts.)
3) Torque bolts in a spiral cross pattern from 1-10 following the numbering outlined above.
4) Torgue steps are: 28, 56, 72ft lbs.
5) You MAY have to check or retorque at about 1000 miles but follow the instructions from your head gasket manufacturer. MOST NO LONGER REQUIRE RETORQUE.

In deference to Edd China: Job Done (well halfway done anyway)
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tyfighter123  



Joined: 19 Jan 2010
Posts: 551
Location: Colorado

PostPosted: Wed Dec 14, 2011 9:18 am    Post subject: Reply with quote

Thanks for posting this it will help a lot.
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Porsche 924 1977 N/A
Mustang GT/CS 2007
Porsche 924S 1987 (parts car)(cut up and recycled)
Porsche 911S 1976
Porsche 931 1980
Porsche 931 1980 (parts car)
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pmcaya2  



Joined: 24 Nov 2005
Posts: 183
Location: Scio, NY USA

PostPosted: Fri Aug 24, 2012 1:26 pm    Post subject: Reply with quote

Nice how-to. And its good advice to re-torque the head at 1000miles.

My brother-in-law helped me replace the head gasket on my 924 and he nagged me about re-torquing the head. (I probably would not have done it on my own).

George was absolutely right - thanks George - it did need to be re-torqued, it was fairly easy to do, and you probably can preserve your valve cover gasket, so no money out of your pocket - only cost is your time. Don't be lazy - complete this step - and you will never have a cylinder head leak. - Peter
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deborah5123  



Joined: 03 Aug 2014
Posts: 20
Location: Waterford, MI 48328

PostPosted: Wed Aug 13, 2014 5:08 pm    Post subject: You still have nice how-to Reply with quote

It is your own experience thus it is proven and tested that you have good ways of assembling and disassembling.
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Rasta Monsta  



Joined: 12 Jul 2006
Posts: 11723
Location: PacNW

PostPosted: Thu Aug 14, 2014 1:34 am    Post subject: Reply with quote

Some might set the motor a squidge past TDC so no pistons are at deck height, in order to further protect the valves.
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  • WeiBe (1987 924S 2.5t) - 931 S3
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!tom  



Joined: 28 Aug 2006
Posts: 1930
Location: Victoria, BC Canada

PostPosted: Wed Aug 20, 2014 12:36 am    Post subject: Re: Head Removal Reply with quote

emoore924 wrote:

9-2) An alternative is to remove the nuts connecting the manny to the downpipe and allow the exhaust manny to come out with the head. After all, there are only 3 little nuts. How hard could it be ;) Pick your poison I say.

Last time I checked there were 5 nuts for this joint.
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