4.2L Audi S4 valvetrain or chain tick

[nwskipro]

I've been chasing a constant tick since first installing a junk yard replacement. Did a full timing chain job on the replacement engine before install. Have pulled the engine one time since and disassembled/cleaned all lifters to no avail. Blackstone analysis is pretty clean, no indication of rod/main bearing.

Video running with valve cover removed:

Videos of S4 Tick

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[Trav]

Any engine codes? Did you change the cam adjusters when you had it apart?

 

[Wrenchturner44]

Referencing third video; Sounds more like fuel injector noise than lifter noise. Also I think you are supposed to hold the noise stethoscope at the insulator not on the probe stem. Vibration noise could be absorbed by your fingers / hand that could impact volume of what you are hearing.

 

[FowVay]

Does this engine have a high pressure fuel pump driven by the camshaft? If so, inspect the pump plunger and slide along with the cam lobe for any signs of excessive wear, discrepant dimensional values or impending doom.

 

[nwskipro]

Does this engine have a high pressure fuel pump driven by the camshaft? If so, inspect the pump plunger and slide along with the cam lobe for any signs of excessive wear, discrepant dimensional values or impending doom.

No high pressure fuel pump on this one, that's reserved for the RS4/R8 variants of the 4.2L, but thanks for the thought!

 

[nwskipro]

Referencing third video; Sounds more like fuel injector noise than lifter noise. Also I think you are supposed to hold the noise stethoscope at the insulator not on the probe stem. Vibration noise could be absorbed by your fingers / hand that could impact volume of what you are hearing.

I'll give this another go, didn't realize I was holding the stethoscope wrong - thanks!

 

[nwskipro]

Any engine codes? Did you change the cam adjusters when you had it apart?

No codes, runs great, smooth power delivery. Feels like it should, just doesnt sound like it should.

I either replaced the individual followers (3 per intake lifter, 2 per exhaust lifter) or removed and reinstalled. I made sure each follower moved smoothly. Some were more "stuck" than others.

 

[Oliveoil2]

It sounds a bit like an exhaust leak. I only listened to the first video at idle. Does it get louder with an increase in rpms?

 

[nwskipro]

No, it sort of drowns out with higher RPMs/load.

I put about 4,000 mi on it before pulling again and didn't notice any indication of exhaust leak.

Put another 2000 miles on after pulling again to work on the lifters.

Blackstone analysis came back just a couple weeks ago.

 

[Audiman]

Did you find anything when you took the camshafts out with the movement of that exhaust cam?

 

[nwskipro]

Did you find anything when you took the camshafts out with the movement of that exhaust cam?

Couldn't find anything that was "loose" or indications of improper movement/operation. Lobes were smooth and relatively clean. Added some additional image folder links below.

Thanks y'all

Valvetrain Inspection Before Removing Camshafts - round 2 (after first 4k miles with the tick):

Valvetrain Inspection Before Removing Camshafts

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Timing chain and related components - round 2:

Engine Tick Round 2 - Timing Components at Removal

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