So I did the 105k service myself

- Valve Adjustment
- Timing belt
- Waterpump
- TB Adjuster
- Tensioner
- Idler Pulley
- Spark Plugs
- Drivebelt
- Thermostat

and the engine is making this jackhammer-ish sound afterwards, it seems to be coming from the front of the engine
no Check engine light on

What could it be?

Incorrect Valve adjustment?
Sparkplugs?
Timing belt not lined up?
help

 

to trouble shoot, take off the drive belt.
this will take the pulley's and belt out of the equation.

if noise stops, it has to be a pulley or belt.

if noise continues; it has to do with your timing belt job


You've read my thread; so, I'm right there with you.
I have my car apart with the timing belt area exposed. Ive done this 3 times on my car alone in the last 2 months. lol

 

You're up early!

On Thanksgiving day, had an '04 GTI VR6 with a noise that sounded like the alternator was going to explode, I mean loud. Rather than removing the belt and give a try, sprayed solution on belt and noise disappeared. It was an old belt so will probably replace it shortly, but it has remained quiet since.

 

^right, another trick to the trade.

turbonut

 

Agree to this. Always hard to diagnose where exactly the noise is coming from.
Just fixed a Chevy Aero with a similar noise and it turned out it was a dying spark plug/loose wire combined with a tiny tiny dent in the drive belt.

I wouldn't spray anything on belt. Actually, I would probably, but I would not let anyone do it. Many liquids can be corrosive to belts and last thing I want is someone to tell me I'm accountable for a belt snapping and trashing everything under the hood.

 

Short term band-aid effect and certainly won't hurt a thing.
If you look at CRC Belt Conditioner, it can be used on a serpentine belt.
I would however clean the pulleys with brake cleaner before installing a new belt(s).

 

No issue with water or anything of the sort, but I wouldn't want to see someone spray something oil based on their belts and for the thing to break.
Like brake cleaner or PS fluid directly on the belt would be so bad haha!

 

did you line up top dead center?

OEM Parts or aftermarket?

Any slack on the belt?

how did you install the tb tensioner (the grenade)?

what method did you use to take off the crank pulley bolt?

 

So got back from work and took off the drive belt...
(In hind sight I should have started it up again without removing anything to see if the sound was still there before I changed anything)

Without the drive belt the sound seemed to be gone... or much quieter
I then sprayed down the belt contact surfaces with brake cleaner and tried to get in the v grooved teeth with a toothbrush
put the drive belt back on, and it sounded the same without the belt -- which was with the sound gone/quieter

If i listen HARD i can sort of hear the sound still there, but honestly I'm not sure if its the same sound since there's so many things moving.

(my phone is compressing the audio frequencies so it sounds different in real life)


I compared the sound with this video and its seems to sound the same
@ 34:48



Sooo I think im good... for now


However there is now a suspension squeak that has show up when i took it for a test drive which I'll make another thread for since i dont think its related to the 105k service

 

OP, when you said "jackhammer sound", my first thought was the "loose spark plug" syndrome. Did you check the plugs? Did you use anti-seize and 13 ft-lbs to torque them? If you didn't use A-S, did you torque them to 18-21 ft-lbs?

The compression on the video is so bad that it's really hard to discern any useful sounds, but it doesn't really sound like a loose spark plug. About 3 days after I did my TB, I started getting a weird sound. Turns out it was just the drive belt was slightly mis-aligned on one of the pulleys.