Knock..Knock..Tap..Tap..Tap

[PaPa Bulldog]

is the sound my 98 Jetta makes AHU 193,999 miles, going down the road. Just started doing it a week or so ago. Am very self conscious about it!!! I have always checked my oil once or twice a week usually a wince down, but have always added when I saw low. Used Shell Rotella T every 10K. She starts awfully hard, and shakes. Have an intake and EGR code in the system, Could this be the knocking, engine is trying to work harder? No loss in performance until limp kicks in. Huge plumes of smoke, EMBARRASING!!! Especially if I'm sitting at a light for a long time, and then take off. Not sure when my dad had the intake cleaned last, but know he has had it done about 3-4 times since ownership. I hear a tick, tick, tick, tick only when throttle is applied, and can barely hear it when at idle. If I'm coasting and take the clutch out I can't hear the knocking, but if I shut down to reset the ECU for more power it still knocks at relative speeds. Sounds like it's coming from the valve cover area. I have gotten out the stethescope, but how are you supposed to diagnose a knock in a car that knocks when it's running perfectly??? Lol Any ideas folks??? People at work think it's either a wrist pin, or a crank bearing, but I'm standing by that it's top end!!! Are there any weak spots people know about in these engines to give me an idea on where to start looking? I know my injectors probably are due for a change out. What does injector knock sound like? Would they only knock with throttle applied? As I have said car has plenty of power until limp, what are the symptoms of bad injectors??? Would they knock at idle, or with throttle only applied? Where should I start?


Thank you in advance


Papa Bulldog Aka Bart

 

[Herm TDI]

How old are the cam followers?
You should pull the valve cover and have a good look.

 

[PaPa Bulldog]

How old are the cam followers?
You should pull the valve cover and have a good look.

Herm, Thank you for the reply. I'm guessing they have never been changed, but I could be wrong. When you change a head are those usually R+R'd? I know the head warped in my dad's possession. Are Cam followers a known problem with the AHU? When I have the VC off where am I looking? How do I pin point if they are bad? Thank you again Herm. You are the man. How have you been feeling Herm? I know you had some health issues recently

Herm can you answer a question I asked in my first post? Why when if I sit at a light or sit idling for a minute or two, and then take off is there a huge plume of smoke behind me?


Papa Bulldog aka Bart

 

[TonyJetta]

If you hear the tap-tap-tap only when the car is in motion, I would suspect a CV joint. What is the noise like around corners? Louder left or right?

tick-tick-tick might be the lifters, as herm mentioned.

Tony

 

[PaPa Bulldog]

If you hear the tap-tap-tap only when the car is in motion, I would suspect a CV joint. What is the noise like around corners? Louder left or right?

tick-tick-tick might be the lifters, as herm mentioned.

Tony

Good thought Tony, but it's absolutely in the drive train, and not a bad axle. I wish an axle was my issue, it sounds like it could be more terminal!!! It is more like a tap tap tap, and a knock when I increase speed. Why though when I take the clutch out does it go away? Thanks for the help, any other ideas? why do I " Load " up at idle???

 

[TonyJetta]

Clutch out, meaning engine disengaged from the trans, right?

What about the ring gear side loading whe under power and centering when not? Some transmissions have issues wih rivets on the ting gear coming loose and eating the case.

What about the diff output / axle shaft bearings?

Tony

 

[PaPa Bulldog]

Clutch out, meaning engine disengaged from the trans, right?
What about the ring gear side loading whe under power and centering when not? Some transmissions have issues wih rivets on the ting gear coming loose and eating the case.
What about the diff output / axle shaft bearings?
Tony

Tony again I appreciate your thoughts and input, but this is absolutely a drive train noise. I'm almost 99% positive! What I meant is with it out of gear coasting to a stop, or down a hill I can't hear the knock. To check my cam followers what am I looking for? Can I safely run the engine for max 5 seconds with the VC off???

I'm going to try to take some videos, and will post them to let you guys hear what the noise is, and what you think.

 

[Herm TDI]

Cam followers look like this:



Installed they'll look something like this:

 

[PaPa Bulldog]

Thank you Herm nice pictures. I pulled my VC this morning. Broke the bottom part of the hockey puck Couldn't replicate the noise when I had the cover off! How much clearance do the followers need between the lobes. There isn't an adjustment that I could see either! Wierd how when I am coasting and take it out of gear the tick goes away.

 

[Herm TDI]

Hydraulic

Thank you Herm nice pictures. I pulled my VC this morning. Broke the bottom part of the hockey puck Couldn't replicate the noise when I had the cover off! How much clearance do the followers need between the lobes. There isn't an adjustment that I could see either! Wierd how when I am coasting and take it out of gear the tick goes away.

These are Hydraulic lifters as such there is no adjustment. However there is a maximun clearance of 0.1MM

• Remove cylinder head cover.

Turn crankshaft clockwise until camshaft lobe for valve lifter to be tested is pointing upward.

Check clearance between cam lobes and valve lifters.

• If play is greater than 0.1 mm, replace valve lifter. If minimal play of 0.1 mm or no play is measured, continue procedure as follows:

Press valve lifter downward with a wood or plastic wedge. If there is a gap of more than 0.1 mm until the valve begins to open, replace lifter.

Note:

• After installing new valve lifters, the engine may not be started for approx. 30 minutes. The hydraulic equalization elements must seat themselves (otherwise the valves will crash into the pistons).

It is of the general consensus that the cam followers should be replaced as a full set (8) and not just 1 or 2 .

 

[TonyJetta]

It is of the general consensus that the cam followers should be replaced as a full set (8) and not just 1 or 2 .

Along with a new Camshaft!

Tony

 

[PaPa Bulldog]

Hello all,
Just wanted to give you guys an update as to where my engine was. I was hoping the knocking sound was coming from an injector, or the followers Sounds like something is going south in the bottom end Strange how I always checked my oil daily, guess crank bearings are a wear item???

Ok now my engine's toast. What now? I really love the car, and want to repair. What would you guys do? Replace only what's bad with a rebuild kit, or find a drop in? I have close to 200k Miles. I can't seem to find anyone with a drop in, or even a wrecked car with power train. Where would you guys go to find a long block, or individual components? Is so embarrassing riding around making such a racket!!! Let me know...


Papa Bulldog aka Bart

 

[TonyJetta]

No idea how close he is to you...this user is advertising a 1Z short block for sale.

Tony

 

[PaPa Bulldog]

No idea how close he is to you...this user is advertising a 1Z short block for sale.

Tony

Tony, I appreciate you looking unfortunately I'm in Vermont, and Michigan is a ways away Keep looking for me please! What should I do a complete replacement, or rebuild faulty components???

 

[PaPa Bulldog]

Hello all,
Just wanted to give you a SAD update I pulled my valve cover off, and couldn't find any loose lifters or followers, so then I pulled my oil pan. That told the story of what had happened!!! There were countless shards of gold like metal pieces marinating in the oil. A piece of my oil pan baffle had broken off, and then got sucked up by the oil pump! Great how was I supposed to know that was happening? You can look right up and see the scored piston!!! What do I do now? I can't even find a locally wrecked car to pull goodies from. I really don't want to have to go back to spark plugs, and really love my TDi it's so worth every penny. Please can you calm my fears and give me advice as to what I need to do.


Papa Bulldog aka Bart
I'm beside myself right now looking for an engine! No luck what so ever!

 

[TonyJetta]

Keep your eyes on 'for sale' on the tdiclub, and on the vortex. You will see TDI's being parted out, just maybe not in your part of the country.

IIRC, boraparts.com (member bleachedbora) I think can get imported engines from european junkyards for fair pricing.

car-part.com is another source, but the junkyards will charge through the nose!

Tony

 

[paramedick]

Hello all,
so then I pulled my oil pan. That told the story of what had happened!!! There were countless shards of gold like metal pieces marinating in the oil. A piece of my oil pan baffle had broken off, and then got sucked up by the oil pump! Great how was I supposed to know that was happening? You can look right up and see the scored piston!!! I'm beside myself right now looking for an engine! No luck what so ever!

Really sounds like what happened to Growler's ALH engine. In his case, a wrist pin assembly let go, wrecking piston/cylinder. Yup, gold colored metal from the bushing.

There are engines out there. Many "auto recyclers" will ship.

When I needed a short block a few years ago, I found an outfit in Las Vegas that imported engines from Germany. Got a 50K AHU short block for $1300 shipped to my door. Let me look for their info.

 

[TonyJetta]

There is a place in socal...lemme think and I'll reply tonight.

Tony

 

[PaPa Bulldog]

Just a quick question does anyone know if my head has cylinder sleeves? I'm sure the piston did some damage up top. Does it sound like I would need to have my head honed??? I have a bottom end lined up for sale, and was wonderin if I needed top end work done too??? Thank you


Bart

 

[TonyJetta]

Is there any visible damage to the head?

You could have Franko6 check it out. See the link in my signature, "cyl Head repair".

With that many miles, it would be a good idea to get it freshened up!

Tony

 

[PaPa Bulldog]

Is there any visible damage to the head?

You could have Franko6 check it out. See the link in my signature, "cyl Head repair".

With that many miles, it would be a good idea to get it freshened up!

Tony

no visible damage to the head. My father cooked the head 15K ago, and that has been replaced, so I think I'm safe there. I really don't think the middle piston did anything, but could pull it to check!



Bart