2002 A4 Avant 3.0 Timing belt urgent help needed

[peoria]

Hi
I have 2002 A4 Avant Quattaro 3.0 engine - the timing belt is broke.
I have open it up all the the way to cam pulleys and stuff and ready to put a new belt in there

I have couple questions

1. How do I know my valves are not bent? Is there any method or techniques I can use to verify that valves are ok without taking the head apart?

2. How do I can align the timing between Cams and crank now ? As I can twist the crank to its mark but how I can timing align the both cams?

do I need to rotate the both cams to a certain position before inserting the cam lock tool? what if the cam is stuck and not rotating?

any help will be appreciated
Thanks

[john_gonzo]

A valve clearance check with feeler gauges should reveal which valves are bent. A bent valve won't seat all the way - clearance will be larger than other valves of the same type (intake/exhaust). Performing the clearance check without the timing belt installed may be challenging.

Second method is a cylinder compression check. However, this requires the timing belt to be installed, etc.

[peoria]

Thanks John
what I will do is installed the timing belt using the cam locks and mark on crank shaft pulley
after that do the compression test and hope for the best
any other suggestions?
Thanks

[john_gonzo]

Yeah, make sure the cams and crank are rotated to the correct positions before installing the belt! I'm not trying to be a smart ass, I just think getting your engine into the correct configuration is not trivial. I was still thinking about this after my first post. Here's what I have so far:

1. Remove all spark plugs.

2. Note: Crankshaft rotation direction is clockwise when looking at the front of the engine.

3. Rotate crankshaft to near TDC. (I don't think the TDC mark on the crank pulley matches cylinder 1. I think it applies to cylinder 3 but please research that.) Anyway, rotate it until it is approaching TDC. We want it rotated so none of the pistons are at the top of the stroke because we are about to rotate the camshafts while the crank is stopped.

4. Rotate each camshaft to the correct position to install the cam lock tools. (See notes below.)

5. Finish rotating the crank to TDC. Install crank lock pin.

6. Proceed with timing kit installation.

NOTES:
I don't know if the cam lock can be installed when a cam is rotated 180 degrees out of position. It seems like it could be, which is bad. To avoid this, the only thing I've come up with so far is to position the cams by thinking about the firing order, then following the cam lobes to see which valves are being opened. When the lobes push open the correct valve with respect to the crank at TDC (#3 or whatever), then that cam is correctly timed.

[john_gonzo]

If the timing belt broke while the engine was running, it is very likely some valves are bent. Sorry for the bad news.

[peoria]

Thanks John
that was exactly my action plan
Rotate the crank until its TDC based on cylinder 3
cam lock both side based on correct orientation of cam lobes
Install the kit
and Hope for the best
Thanks again

[SJorge3442]

Just to chime in here, my cam tools DO NOT let you lock them in if the cams are 180 degrees out. They only fit the slots one way. I imagine some cheaper versions of the tools may allow for reverse install though.

[peoria]

Installed
Seems like everything is good - good pressure - no bent valves

Thanks for all help

[john_gonzo]

Just to chime in here, my cam tools DO NOT let you lock them in if the cams are 180 degrees out. They only fit the slots one way. I imagine some cheaper versions of the tools may allow for reverse install though.

SJorge, thanks for adding this. What prevents installation of the tool when the cams are 180 degrees off? The flats of the camshaft (where the tool grips) seem symmetrical.

- - - Updated - - -

Installed
Seems like everything is good - good pressure - no bent valves

Thanks for all help

Wow! This is good and unexpected news.

[SJorge3442]

SJorge, thanks for adding this. What prevents installation of the tool when the cams are 180 degrees off? The flats of the camshaft (where the tool grips) seem symmetrical.

The cams look symmetrical, but they arent. The one side (wrong side) of the slot is slightly wider than the correct side, which is what prevents the cams from being inserted. I know first hand because when my timing jumped when my car rolled backwards 2 years ago, I had a quite the hard time trying to turn the cams over by hand to get everything lined up hard. Its pretty difficult to manually rotate the cams with all of the springs. Try doing that, while trying to keep the other cam on the head from spinning out of position. Everything is so sensitive. One small vibration and the other cam would just rotate. its a balancing act.

[john_gonzo]

The cams look symmetrical, but they arent. The one side (wrong side) of the slot is slightly wider than the correct side, which is what prevents the cams from being inserted. I know first hand because when my timing jumped when my car rolled backwards 2 years ago, I had a quite the hard time trying to turn the cams over by hand to get everything lined up hard. Its pretty difficult to manually rotate the cams with all of the springs. Try doing that, while trying to keep the other cam on the head from spinning out of position. Everything is so sensitive. One small vibration and the other cam would just rotate. its a balancing act.

Understood. Simple and effective.

Yeah, I remember your thread about that! That was a bizarre one.

Thanks for the info.