Fixed Ticking ALH - Found a Bad Lifter....
Some information to hopefully benefit someone in the future....
- 2000 Jetta ALH manual 300k+ miles - ticking since we got it about 3 years ago.
- Oil pan had been cracked, but we did not know how much it had been driven with low oil pressure.
- Ran great except for the constant tick.
- Ticking was steady and did not change with engine load or with oil changes/ RPM, temperature etc. Very noticeable off throttle coasting down hill when the injectors and pump are quietest.
- Slowly got louder over 3 years.
- Multiple attempts with a mechanic's stethoscope and neither my son nor i could pinpoint the tick.
- 6 months ago, removed valve cover and pressed on all lifters....all felt the same, no signs of uneven wear on lobes or lifter faces.
- When we replaced the timing belt and oil pump chain, I verified no play in the rod bearings.
- 1000 miles of Marvel Mystery Oil (1 qt) in the oil did nothing for the tick.
- Found a deal on some INA lifters so removed the valve cover again.
- Visually everything looked consistent and decent.
- Pressing on all the lifters, they were firm.
- BUT, we used a strong magnet to pull up on each lifter when it was off the lobe....BINGO one lifter that looked fine was flat / not springing up enough. Without the magnet, we might have missed it again. It was the last lifter on the number 4 cylinder. (Thanks to [486] for suggesting that I may need to lift up on the lifters!)
So, we removed the timing belt cover, rotated the engine to align properly at TDC, marked everything in case we had to take the belt loose. We also removed the lower turbo hose to make turning the crank easier.
Removed the top roller of the timing belt to give some slack or at least lower the tension.
Removed the vacuum pump...pulled it away a little to disengage from the camshaft.
Removed the cam bearing caps after marking them.
Carefully tilted the camshaft and lifted out the bad lifter with a magnet and fingers.
Disassembling the lifter, we found the inside clean, but the top of the inner piston/plunger was worn away and slowly eating its way up through the inside of the main lifter body towards the lobe. Eventually it would have gotten through and ruined the lobe and more.
Coated the sides of the new lifter with fresh engine oil and the face with a little assembly lube. Dropped it in and assured smooth rotation in its bore.
Now carefully placed the camshaft back in its bearings tightening multiple caps a little at a time. Had to gently push the cam pulley toward the vacuum pump because the belt tension was pulling it out of position.
Last cam bearing cap installed was the one at the pulley....paid special care to the oil seal...back straight in its original position as I placed the cap on.
Evenly, slowly torqued all of the bearing caps.
Triple checked the timing marks....nothing moved, no teeth ever disengaged. Reinstalled the top roller of the timing belt.
Replaced vacuum pump then valve cover.
Turned the engine with a ratchet several rotations.
Cranked the engine....tense 30 seconds to one minute as the new lifter pumped up....was missing pretty bad. But, it then quieted down...no tick.
Replaced the lower turbo hose and went for a test drive to reach full operating temperature. Success....smooth and quiet...for a TDI.
I am sure that the lifter/lobe will wear unevenly compared to the others....but this fix should get my son back to college. We can replace the camshaft and all lifters at a later date if the rest of the vehicle survives! (Turbo seems to be passing some oil.)
Thanks so much to all members of this forum for the thoughts and information that allowed us to make this fix for $13.
Scott