924Board.org

JB 924 · Joined: 03 Apr 2006 Posts: 606 Location: Hessen, Germany

Hi there,

I've been watching this forum for a while now and this is my first post. I have a problem with my 78 924 NA. I bought it about four weeks ago from a guy close by and he had it standing for 1 1/2 years. The car runs but there are a few minor things that need to be fixed. The car starts but there is valve ping, so today I tried to do the timing. The engine is still in the car and I'm looking down from the left side into the window in the bell housing, but I can't seem to find the OT mark on the flywheel. I turned it many times but all I can find are two parallel lines. Are these the right ones? I read somewhere they should be used when looking from the bottom. Anyway, when these two lines are centered in that window, the indentation on the cam sprocket seems to be almost dead on with the "point" on the cam cover. If these are the right marks, could it be that the pinging is just from carbon build up? Or is the OT mark somewhere else? Any help would be very much appreciated.

Thanks

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

Hi JB, nice to see another 924 guy so close to Edmonton.

I find the best way to locate Top Dead Centre (TDC) for the #1 piston is to use the pulley on the crank shaft. The rear side of the pulley has a very small notch on it which lines up with a small pointer sticking out of the oil pump when the #1 piston is at TDC. One of the board members has a great picture of this, I can't remember who, but I'm sure they will post it once they see this thread. When these markers line up, and the markers on the cam sprocket and cam cover line up, then you are accurately at TDC. I only ever use the hole in the bell housing when using a timing light, I find it too hard to see while trying to turn the crank shaft by hand.
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1987 951 - M193 Version for Japan

JB 924 · Joined: 03 Apr 2006 Posts: 606 Location: Hessen, Germany

Thanks alot Chrenan! I'm gonna check it out right away after work tomorrow!
I hope I'll get it fixed so I can finally drive it to school.

Gracie · Posted: Thu Apr 06, 2006 1:21 pm Post subject:

yay! Another Alberta 924 type person. Welcome to the board.

chrenan is right but I'd double check using the hole in the bellhousing.
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Working on cars is restful for they have neither conflict nor emotion.

Time with cars is never wasted, even if all you do is stand there and curse at the unfinished impossibly curved 1/4 panel.

JB 924 · Joined: 03 Apr 2006 Posts: 606 Location: Hessen, Germany

Thanks for the tip!
I put the timing belt on the day before yesterday and the timing seems to be dead on but I'll still check it.
By the way, after putting the a/c belt back on, do you ever have problems with getting it to line up correctly
with the crankshaft pulley? My a/c seems to be just kind of hanging there. I tried to tighten the bolts but can't
tighten it so it lines up properly.

Thaks,
Jens

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

The rubber bushings in the mounting bracket are probably shot.

If you have dealer installed ac, then the same bushings are used for the alternator and the ac compressor. When they rot, then the pulleys don't line up correctly. There is supposed to be a metal spacer inside of the rubber bushing (sold separately).

If you have factory installed ac (VERY RARE), the bushings on the ac mount are unique, and will probably need to be ordered (hopefully not from Germany).

Aftermarket Autoparts Suppliers often have replacement the common replacement rubber bushings, but not the metal spacers. Porsche superceeded the rubber bushings to poly bushings close to 20 years ago. Porsche Dealers do not sell the rubber bushings anymore, but the price was vary similar for the rubber and poly parts. They were around $2 each, last time I bought some.

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

I don't have AC, so I can't help on that one. But Gohim is definitely right on the alternator mounting bushings (upper), once they rot the alignment of your pulleys becomes less than perfect.
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1987 951 - M193 Version for Japan

-nick · Joined: 16 Nov 2002 Posts: 2699 Location: Cambridge, MA

side note - the factory installed AC was pretty standard on 77.5 and up. the '76-early '77 would most likely have the dealer installed AC. You should have factory AC installed on yours (i.e., you've got the big rotary snowflake AC knob).

nick

Smoothie · Posted: Fri Apr 07, 2006 12:53 am Post subject:

For the AC compressor, the adjustment parts are the same between 924NA and 931, so these diagrams and pics should apply (3 pics starting here) -
http://pg.photos.yahoo.com/ph/smoothies931pics/detail?.dir=/bdb3&.dnm=f0ac.jpg&.src=ph
Parts numbered 1, 2, 3 and 4 set the adjustment. (1 and 3 are labelled in the second .jpg) First, make sure it's assembled correctly - Looking at the first .jpg, you see a slot and a notch above #4 in part #11...the nut and washer (#1 and #2) have to be to the left of the notch. Then tightening #1 will increase tension on the belt. (#3 of course has to be loosened before and tightened after.)
Obviously, you also need the correct size belt, so if there's any doubt about that, post it and we can check that it's the right size.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

Might also want to check the bracket (#13 on the diagram) to make sure it's not broken. I just replaced mine. It was broken, making the compressor sit out of whack, not to mention the belt was loose and not able to be tightened because of the broken bracket.

The belt was available at the local NAPA. They had two, one for $4.00 and one for $11.00.
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'80 924 n/a SOLD

JB 924 · Joined: 03 Apr 2006 Posts: 606 Location: Hessen, Germany

I checked the bushings and they're fine but I'm pretty sure I found the problem. One of the bolts holding the compressor in place is missing which is why it has so much free play. I believe it is bolt #29. Thanks for the tips though, I never thought of checking the bushings or anything.