part number and source for lower intake manifold o-rings
 

trying to wrap up my 1991 V8 Quattro five-speed resurrection project. by way of update, the frame/rail has been straightened, and the crumpled section cut off and replaced by a metallic pearl donor section (thanks Eurotrash Motorsports, Snohomish, WA).

now its gaskets, o-rings, and seals time from the valve-covers on up. sadly, this also includes a new oil return tube, as mine was bent in a tragic having-a-garage-door-close-on-it-while-it was-sticking-out-of-the-front-of-the-car mishap:

https://cimg8.ibsrv.net/gimg/www.aud...471723781.jpeg
https://cimg9.ibsrv.net/gimg/www.aud...c06707de2.jpeg

that was a bad day, but i digress. my current problem is finding the o-rings that fit into the grooves on the top of the Lower Intake Runner:

https://cimg2.ibsrv.net/gimg/www.aud...2f8f4a23b.jpeg
https://cimg4.ibsrv.net/gimg/www.aud...a394ecf9c.jpeg

part number 034115427 from oempc.com got me o-rings that were a lot smaller than the ones that i removed when i split the halves of the intake manifold to clean it up. has anyone ever replaced these o-rings, and if so, where did you get them, and what p/n did you use?

According to etka those should be the right o-rings. What do the ones you got look like?

thanks for confirming yoda. i ended up ordering eight of these from McMaster-Carr:

Chemical-Resistant Viton Fluoroelastomer O-Ring, Super-Resilient, 3 mm Wide, 50 mm ID, Packs of 5

$9.36 per 5-pack. this is what they look like (left to right, originals, ones that came from FCP Euro, and ones that came from McMaster-Carr):

https://cimg5.ibsrv.net/gimg/www.aud...0a62c9200.jpeg

i am going to reuse this o-ring (p/n 077133237B):

https://cimg2.ibsrv.net/gimg/www.aud...c3f1c41a2.jpeg

the only place its still available is via Audi Tradition, and its just not shabby-looking enough to jump through all of those hoops (they still won't let US customers order directly online, last i checked).

then last but not least, one more stumbling block appeared out of nowhere to slow my progress: broken water pump bolts. going to try to extract as many as possible. threaded holes are badly damaged will likely get timeserts. wish me luck!


https://cimg4.ibsrv.net/gimg/www.aud...f6a170fa5.jpeg

https://cimg1.ibsrv.net/gimg/www.aud...8698486f4c.jpg
Hey, sorry to see that pic of the water pump. I sent that to a guy that was a V8 guy for years and after having to deal with that during a belt job had had enough and got rid of the car...He said he used a steel spring pin that fit into holes in water pump and placed pump in place to use the spring pin as a guide to start the drill bit dead center. Also thanks for the size of o-rings as I will be in there replacing the head on Lago at some point and it's nice to know ahead of time how big. I dug thru my mess and found an oil cooler/lines, but are pretty ugly compared to yours....If you can't find anything better, you can have for shipping. Might also be able to cut out bend and braze a section of pipe in there. I'm rooting for you to get this back on the road....Good luck, Tom

Tom,

thanks for the encouragement and the offer. Believe it or not, the oil return tube itself, though bent, does not appear to have cracked/split during the straightening process, so I am going to reinstall and check for leaks regularly while I continue to reassemble the front of the car.

Thats a a good idea re: the spring clips. I had already considered using the old water pump as a drilling template after I botched one of the first 4 screws that I tried to drill out and realized that the “freehand” approach would likely end in disaster if I continued on that road, and I was going to make a plexiglass template using the old water pump as a guide, but o think the spring clip idea is the easiest route to pursue at this point. I will post when the holes are cleaned up and ready for the new water pump.

Vince

Yeah, I thought that spring pin idea was great.....I've been off just enough many times that I couldn't just chase the threads and wished I had a jig, but if you found the right pin, it's perfect. Still nobody's idea of fun. On a different note, if you don't know of the 50/50 acetone/ATF mix as a penetrant, it's my go to on anything that's really frozen. A guy did series of tests on all the available penetrants, and the 50/50 beat them all....Acetone really wicks it in there. There's also Freeze-off which is a penetrant with a freeze spray so I torch/freeze/torch/freeze then hit it with the 50/50 and if enough stub left might just get them out.....I'll do that before I get out the drill as I"ve been off enough times to call that last resort....If you prepped enough with the penetrant a reverse bit sometimes will also spin it out.....Good luck, I don't envy that at all....Tom