BC

I'll have the engine out soon, and while I have it checked for valve seating and trueness, I will need to take all the valves and springs out.

I know, a bit complex, but I have a mechanic close if I get lost.


And yes, its pertinent for this, since I have littl emetal shavings all over the place because three (3) freaking cam bearing bolts stripped.

Thom1

Hi Brendan,

For proper maintenance, I would replace all the rubber e.g. hoses and sleeves, seals, gaskets, wearable parts, exhaust valves, chain tensioners, etc.

Use lots of P’Blaster penetrating oil on cam end bridge bolts. Tap them once each with a punch to loosen them. The bolt shafts are tiny, and will break really easy.

Stuff paper towels down into head holes before the tensioner washers, etc. escape to the underworld.

Use of special tools for removing cams can be avoided by loosening cam caps a very little at a time in criss cross pattern from inside out. Do this at your own risk. Cams have been snapped by not using the right tools. Install in reverse manner.

Have intake, cam covers, and filler neck bead blasted and powder coated.

S4s have a ball and spring check valve. I am not sure if you replace those. Many parts will be different from my 1986 parts list.

Devek rents a useful tape for doing timing and camshaft removal.


See the following document for more tips:

Thom’s Cam Cover and Intake Service and Painting Essentials:

Thoroughly clean the engine first, without removing any factory stickers.

1986 model recommended replacement parts:
Rubber Intake Manifold (Intake) Sleeves
Rubber Vacuum Elbows
Intake Sleeve Hose Clamps – New ones look better
Rubber Intake Hoses – Most of them are formed.
2 O-Rings at air flow meter
Cam Cover Breather Hoses (on one side)
Check Valves at chain tensioners
Crush Washers for check valves and tensioners
Thermostat
Thermostat O-ring
Fuel Injector O-rings
Oil Filler Neck Baffle
Oil Filler Cap O-ring
Cam Cover Gasket Set – May include the following – Verify contents:
Camshaft Seals
Camshaft cover bolt Seals
Cam Cover Gaskets
Cam Cover Seals for plugs (on one side)
Cam Cover Plugs (2 on one side)
Cam Cover Breather Hoses (2 on one side)
Spark plug hole Sealing Rings
Intake Gaskets

If removing cams, for the chain tensioner service add:
Chains
Tensioners – only if deeply grooved (in my opinion)
Loctite 574

Note: When I removed my intakes I had to replace all the rubber up there. This includes vacuum sleeves, vacuum elbows, and hoses. The rubber has been cooked so much by now that it is stuck in an inflexible shape, and it will leak after it is disturbed.

Warning: My washers, beneath the cover bolt heads, had a cushion of rubbery looking substance stuck beneath them about 1/16th inch thick. Upon investigation, none of the big 3 could find a part # or reference to this part/substance. Other 928 owners told me that a spacer is required for my model to prevent leakage at the cover gasket. Therefore, if your washers have spacers stuck to them, leave the spacers alone.

Note: The Allen Head bolts may be very stubborn. Have a good 3/8 inch socket type of Allen wrench on hand.

A hose, plastic, rubber, etc. replacement list for engine top side from 928 Specialists follows:

Hi,
Here is a text description of the hoses for 85-86 , hope this helps.
N.020.139.1 Hose - Rigid Vacuum Line (per Meter) 3 x $2.48 = $7.44
928.110.248.03 Intake 85-86 Sleeve - Throttle Body>Center Intake $10.19
999.701.699.40 Intake 85-86 Seal - Large - Mass Sensor>Air guide $6.38
999.701.183.50 Intake 85-86 Seal - Small - Mass Sensor>Air guide $2.28
999.701.436.40 Intake 80-86 O-Ring - Air Guide>Throttle Body $8.68
928.110.347.00 Intake 85-86 Rubber Seal - Large(2 req) 2 x $13.75 = $27.50
928.110.343.00 Intake 85-86 Rubber Seal - Small(8 req) 8 x $2.81 = $22.48
928.574.717.02 Vacuum - Rubber Elbow 10 x $2.63 = $26.30
928.110.441.02 Vacuum - Splitter - 7way@rear of Intake - Auto $18.71
928.110.243.02 Intake 85-86 Sleeve - Mass Sensor>Airbox $12.93
928.110.602.00 Intake 85-86 Hose - "T" > Center Intake Port $12.47
928.110.673.00 Intake 85-86 Hose - "T" > Vacuum Valve@x-brace $20.71
928.107.601.00 Intake 85-86 Hose - "T" > Oil Fill (short) $15.91
928.107.445.00 Intake 85-86 Hose - CmCover-Front>Oil Fill $29.43
928.107.313.00 Intake 85-86 Hose - Oil Filler>Air Guide $21.22
928.110.442.05 Intake 85-86 Hose - Idle Valve>Air Guide $10.10
928.110.174.08 Intake 85-86 Hose - IdleValve>Center Intake $18.76
928.110.432.00 Intake 85-86 Hose - CmCover-Rear>Air Guide $18.54
928.110.014.00 Intake 85-86 Hose - Throttle Body>7-way Tee $3.71
928.110.761.01 Intake 85-86 Hose - Pipe@L-Intake side>Air Guide $10.22

David Roberts
90 GT
89 GT
85 928S Euro 5-Speed

928 SPECIALISTS

BC

Thanks Thom. My 928 is an 89, so there are quite a few different parts, and I will be actuall REMOVING the wngine in a few days (finally), so the work will be (to me) much more pleasant. My idea was in checking to make sure there are no "YOU MUST REMEMBER HOW THIS ONE DUDAD WENT IN, BECAUSE THE PORSCHE POLICE WILL COME AND GET YOU IF ITS INCORRECT" type of things.

The intake has been off for a while now, and many of the pieces are being changed to benefit power and no MAF or normal J pipe instead of stock Porsche parts. Though I am keeping it as original as I can with the DTA.

Thanks,

Jfrahm

I have done this on a 944S2. It was no picnic.

To remove the valve guide seals, I took a small screwdriver and cut a V notch into the tip, then sharpened the screwdriver. I used this tool to split the valve guide seals for removal rather than buying the correct tool. It worked quite well.

The cam chain tensioner pad is dirt cheap from Porsche ($3 or so per side.) These last 120K miles or so on a 944S2, but much longer on a 928. The cam chains are also quite reasonable, but I don't know if it's wise to mix old cams and a new chain unless you need to.

Mark your sprockets so you can get the cam timing close (I assume the 32v motor uses the adjustable cam sprockets?) Measuring the lobe lift to sort out the valve timing is a challenge.

Label your lifters so you get them back in the right holes.

If you can invert the engine to clean it, that might be a good idea. I think you get a lot less dirt in the bores this way (it falls out when the heads are removed.)

I stripped my cam cover with Aircraft Stipper, then painted it with engine paint. Powdercoating would be better but I had not planned ahead... plus I just close the hood and no one sees it :-)

-Joel.

Tony

"i just want you to know, we're all counting on you"

Kevin in Atlanta

To your original question. The camshaft bearings caps and cams come off to give you access to the final set of head bolts. Keep them in the same orientation for reassembly later. You will have to remove the tensioner assemblies, too. Carefully back off the head bolts evenly. Be prepared to catch the antifreeze and oil still up in the heads. You may need a 3-6' breaker bar to separate the head from the block.

Lagavulin

Wow, this is some good information!

tresamore

Brendan,
Start looking for a valve seal installation tool now. I waited until I was ready to install the seals and couldn't find one. I was close to having to wait 3-4 wks for one from Germany until I was able to borrow one at the last minute. I was told you can put them on with a 1/4" drive 1/4" socket and extension and tap them on, but I would not reccomend it. If you push them on too far they crown over the valve guide and will be ruined or will leak if you don't catch it before re-assembly. If you don't put them on far enough you risk them coming off and leaking. Seeing as you will have do this 32 times, the odds are against you for guessing them all correctly. The tool leaves no room for error and works perfectly if you follow the manual.

BC

Do you have that tool number Tresamore? Anyone see good deals on valve spring installation tools?

RyanPerrella

Brendan,

Can you please share with me how you removed the stripped cam bearing cap bolts? I have a couple on one side and its preventing me from removing said head.

Could you e-mail me or post about your specific experience about how you did in fact get these damn bolts free. And please be as specific as possible, that would be a huge help.

Many Thanks!

Koenig928

Hey Brendan,

I must have missed this thread before (been busy putting my own motor back together). Can definitely help you here. I made my own valve spring and valve guide seal installation tools, made from local materials, copied from the WSM's.

I completely re-did my own heads on the workbench at home (new valve guide seals, carbon removal on all valves, re-ground valve seals, etc.) with the exception of having the heads skimmed 0.003" at a local machine shop.

Give me some time to post pictures.

Dave Howerdel

3yr old thread. even his username has changed.

RyanPerrella

yes it is an old thread

I came across it and was curious about how to get stripped cam cap bolts out as he mentions it specifically in here.

Anyone else have suggestions for removing these bolts?

Koenig928

Dooh! - guess I really missed it. Fubar on me then (too much drinky last night...)

Ryan try this - I picked up this bolt-extractor socket set from either HomeDepot or AutoZone, worked pretty darn well for me in removing stripped bolts.

I'm looking at an old bearing bridge and bolt, the "1/2" sized socket just fits over the bolt head. These sockets cut into the bolt head in reverse direction so you can grip it and back it out.

Good luck.

RyanPerrella

really

thanks for the pic, honestly i didnt think that type of extractor would work honestly but clearly it will fit onto the cap.

I will pick a set of these up, thanks for the suggestion and even more thanks for taking the time to take pics, much appreciated.