1980 924 Turbo Restoration Project
 

https://cimg7.ibsrv.net/gimg/rennlis...8996008c85.jpg
This is/will be the restoration thread for the 1980 924 Turbo I got last spring. A relatively clean M471 car with 52,000 miles. Long story short: A friend of mine purchased the car non-running from the grandson of the first owner. It sat for over 15 years outside and suffered a moldy interior but clean floorpan and no one knew why it didn't run. I decided to trade my cleaner and running 1984 with 130,000 miles at the time to take on the challenge of fixing it. People thought I was insane for trading cars, until my 944 developed rod knock and got a new motor, oh well.

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After replacing a dead fuel pump and relay, cleaning all the contact points and fuses, and the positive cable from the alternator and starter, it wasn't until a compression and smoke test that I discovered 96% compression leakage on cylinders 2 and 3 and a bad head gasket. I've slowly tore down the engine with the help of diagrams and my four years of ever improving mechanical inclination. Honestly, tearing down this engine was easier than doing the same on the 944; only hampered by a few choice nuts and bolts that connect the turbo to the exhaust manifold and downpipe.
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Finally got the head off with the help of my very good friend who's a 924/931 guru and we determined that the head wasn't original to the car. If you look at piston #2, there’s some light valve marks on it that are gonna be filed out lightly that didn't match the lack of markings on the head, there was no damage on this head. Our conclusion was that someone had f’ed up the timing previously (interference engine), ruined the last head, slapped this one on, didn't put in a thermostat(that was also missing) and one thing led to another to cause a bad headgasket at some point. The pistons had milkshake on them that cleaned up nicely and excess coolant was sopped up. No sign of milkshake anywhere else in the head or visible.

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Currently disassembling the head in my basement while redoing the interior bits that were ruined with the spare parts I got with the car.
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I retrofitted the lower vinyl portions from the ruined door cards to the cleaner cards I had to makeshift an "RS-style" panel; albeit with separate door latches and door pulls because it was easier for me. This weekend I'll have the head fully disassembled and cleaned while I wait for the head gasket parts to arrive. I've also removed the vinyl from a spare cracked dash to re-wrap with marine vinyl.
https://cimg4.ibsrv.net/gimg/rennlis...4df2785f57.jpg

Good Luck on your Project. Keep posting :)

Nice! Should be a fun project. :cheers:

Nice to see progress. keep the pictures coming.

https://cimg1.ibsrv.net/gimg/rennlis...385ea392b7.jpg
This is the final result for my RS-style door panels!

What a great project to take on!! I believe this car will turn out just like you 944..amazing!! Any special option codes? Did any service records or paperwork come with the car? Would love to see some interior pictures!

Many of the parts specific to the 931 are now hard to find. I had difficulty getting the fuel distributor, which is also unique to the 931, properly overhauled. The M471 option is great to have. Good luck with the unique car. I may able to help with technical questions.

Daniel
'82 931 (long gone)
'86 951 (just bought)

For a while I was kicking myself what I did, but I don't have any regrets now. In fact, my 944 is even better than before with it's current owner. Unfortunately, the option sticker was missing, and the only records I've got are the ones my friend and I have done for the car. But looking around and under the car, it was obvious that it was an M471 car. That's about the only option I can verify. I'll take some interior pics when I get home, but there isn't much beyond seats, dash, and no carpet. The gauges are pretty darn cool though! GREEN!!

Yep. Sourcing engine mounts is not gonna be fun or budget-friendly but I'll find them somehow. Fortunately, the car is at least mechanically complete if nothing else. I'm very lucky that my fuel distributor was overhauled. Any help, technical or otherwise, is greatly appreciated!:)

Dont say that too soon...overhauling the fuel dizzy can go wrong so quickly if not done right.
VERY rarely these dizzies need repair...most people do it because...insert silly reason here, and mess it up.

Yes, CIS fuel distributor repair is a specialized job. The shop had mine a while before they got it right. The car had been sitting over ten years. Does yours have the "snail" transmission with the different shift pattern, or the regular "Audi" style transmission?

Daniel
'82 931 (long gone)
'86 951 (just bought)

Mine has the snail dogleg gearbox. When I get it running, I can't wait to try it out!

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The head is fully disassembled!! And learned even more about why the car wouldn’t run. For example, what’s different about two of the eight valves you see? The cylinder 2 exhaust and cylinder 3 intake valves are bent; correlating with the lack of compression on cylinders 2 and 3. So now I have to find both a intake and exhaust valve....And those are NLA and not the same as the N/A 924 valves. If anyone can help me source these valves, I'd greatly appreciate it!
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I've got the typical manifold crack between the 1-2 runners and whoever had this one brazed the hell out of it and it’s nasty. I’ve only welded once and could probably do a better job. I will fix this.

Get some professional help for welding that thing, or try to get an uncracked one.
Dogleg is very special, but you have to be careful with it, linkage bushings are essential for not destroying the syncros and dog teeth.

Please refer to the bushings you mention, partsnumbers if possible. Something worth adressing for all 931 owners whom havent already.

First, i'd like to say that the bent valves seen here may not necessarily be like that because of some engine problem...you may have bent them when setting down the head like you showed in the picture above.
Its a clear rule when removing heads...you DONT set them on the valves...because...they...bend.
Good luck finding sodium filled valves as the 931 has them, perhaps you can find used ones? Ask Dan(ideola) he may be able to help.

this may be because of
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this
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The shifter linkage is nearly identica to the 928 linkage. If i'm not mistaken the bushings are exactly the same between the 924 turbo, 928 and the 915 which also uses a similar gearbox as the 931.
have a look here for some pics and part numbers but do your homework right and search the part numbers in PET.
http://jenniskens.livedsl.nl/Technic...8/MyTip808.htm

the items you want to look for are: 9, 12, 13 and 20.
http://jenniskens.livedsl.nl/Technic.../shiftrods.JPG