CAEB Cam Install - Help

[porschelou]

Hello -
Thanks for having me.. I'm new to this forum.. Bought my first Audi about 3yrs ago ( 11 A5 Prestige/S-line modified) and just purschased a 2010 Audi A4 ( CAEB engine that was blown up). The typical timing chain tensioner issue. The PO had Audi of Winston Salem pull the head and found every valve was broken and chucks out of the combustion chamber. They didn't want it repaired so they tossed every part in the trunk :).. I have rebuilt the engine ( new pistons, new intake cam-bridge had messed up the cam , head was fully reconditioned at Dover Heads in Atlanta, new timing set and so on).. I started the engine last weekend and it ran terrible. Compression was 20psi on cylinders2,3,4 and #1 was at 180psi. Pretty sure timing was dead on.

Pulled the head back off and verified the valves were all fine. I have ordered all new lifters in case I have some dead ones. When the valves hit the pistons 3 of the rocker arms broke so maybe the lifters were damaged - hard to tell.

The factory manual says I need to use this tool when I install the exhaust cam.. I cant really figure out why. The cams don't have the notches so the head gets bolted on first then the cams. Can anyone tell me if I don't use the "red forks" would this cause a mis-alignment with my rockers? I have a set coming for the weekend when I put the head back one.. Just trying to figure out why 3 cyl had no compression..

Thanks

IMG_7140.JPGIMG_7234.JPGIMG_7270(1).JPGt40191.jpg

[casey_tuzziano]

You don't have to use the red handles. Its preferred to use them however. Just be careful not to slide the lobes on the camshaft. The girdle won't fit correctly if the lobes are not lined up. Also I've seen where the camshaft lobes (in this case the intake cam) getting moved, like literally bent so they're not in time anymore. So the timing chain is physically is in time with everything, but the lobes on the cam are not.

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[porschelou]

Thanks for the picture and info.. I will use the red forks this weekend when I reassemble and make sure to check everything. Really hoping it was just damaged lifters causing my issues.
Another question - manual says I need to use the four "pin" tools that insert into the variable exhaust guides. I can tell you are doing this to just move the cam slides a certain direction. Why am I doing this? Manual doesn't say anything. Can't find any videos on cam installation - just timing chains :)

[casey_tuzziano]

Thanks for the picture and info.. I will use the red forks this weekend when I reassemble and make sure to check everything. Really hoping it was just damaged lifters causing my issues.
Another question - manual says I need to use the four "pin" tools that insert into the variable exhaust guides. I can tell you are doing this to just move the cam slides a certain direction. Why am I doing this? Manual doesn't say anything. Can't find any videos on cam installation - just timing chains :)

Those pin tools are used to slide the lobes into the correct position before removing the girdle. Last time I used them, I believe I had to spin the engine over 2 times before I can remove the cams.

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[porschelou]

Thanks for sending me the info.. So - I spent 10hrs on Saturday and replaced the head , set both cams in (I used the red fork tools to set the exhaust cam), layed the timing chain across them cams to line up the marks, Torqued down the valve cover per the manual and installed all of the parts. I even pulled the balance chain and reset it and verified the crank gears were dead on. I"m 99% certain the timing was dead on the money.

Hit the key and it would only spin over.. I checked one cylinder and no compression.. How can that be. I did install new lifters this time around but that shouldn't matter. I pulled the plastic front cover off to make sure the cams were spinning. Thinking the exhaust cam might have spun the gear when the timing chain originally broke - looked correct. If the gear did move - say 2-3 teeth would that give me this issue. Not enough to hit the valves but zero out any compression? There is a youtube video showing this cam that had spun the gear that's what has me thinking.

I did end up installing a Chinese intake cam ( looked the same -even stamped audi and the correct numbers). The cam bridge had messed up he cam. So i replaced the cam and bridge.

Any ideas? I had no compression the first time around as well. I did verify the valves weren't stuck open -put water in the ports to see if water would come out - all good. The head was professionally rebuilt so I don't think it's that.

I'm at a loss. Been building engines for 20yrs and I'm stumped.

[Quattro420]

Remove the intake manifold and see if the valves are closing or open, spray some oil in the cylinder see if the compression goes up. Are the valve springs new and did you compare the Chinese can to your original cam to see if the lobes are correct? Possible when it jumped timing depending on engine speed etc maybe a cam gear sherd it’s lock and spun on the cam

[A4 Centaur]

If you have no compression then its got to be cams not letting the valves seat? How about trying the compressed air trick? See if you can pressurize the cylinder and then wiggle the valve?

[porschelou]

Thanks for the inputs. I very rarely have a mechanical system beat me... So - when I got home tonight I pulled the front cover off of my daily driver which has the same engine. I got both motors set to TDC and spent 30mins' looking at the both cams and using a micrometer took measurements - I don't think the exhaust cam gear was out of time. Talked to a guy on youtube last night since he showed one that had spun so I was really sure that was it - not :(

I like the air trick -- I have the air hose adapter used to hold valves up when changing seals - I'll pressurize the cylinders Wednesday night. I did spin the motor while the intake was off and valves were moving. I guess If nothing else shows its self I'll pull the cam cover again next weekend.. I might see if I can find a used exhaust cam to try that..

And I verified the timing again tonight as well - dead on.
Thanks for the help!

[jfo]

Have you done a leak down test to help rule out piston issues?

[porschelou]

I haven't done a leak down yet. I'll knock that out tonight and see what the results are. Good idea. Should quickly show if the valves are hanging open as well.

Thanks!

[Justinnethers]

You don't have to use the red handles. Its preferred to use them however. Just be careful not to slide the lobes on the camshaft. The girdle won't fit correctly if the lobes are not lined up. Also I've seen where the camshaft lobes (in this case the intake cam) getting moved, like literally bent so they're not in time anymore. So the timing chain is physically is in time with everything, but the lobes on the cam are not.

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Where can I get these alignment forks?...been searching online and not seeing anything...any links?

[Theiceman]

I did it without them. Not much of an issue


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[Smac770]

https://audi.snapon.com/SpecialTools...temId=17870123

Unfortunately, it seems it only includes three /1 pieces, and the manual shows needing four.
Guess that's why the manual also says "you'll need a second set", and why the pic above seems to be missing one versus the manual pic.
Not sure what they accomplish for you.

cam spacers.png