2003 knocking = broken rod ?

[Too Cold NB1.8T]

Fuel wet plugs sounds like too much fuel being pumped into the cylinders for some reason or plugs not firing.

Possible leaking injectors, bad coils, bad coil harnesses/coil plugs, since the problem is persisting after you changed the spark plugs, we can pretty much rule out them as being the cause.

[dhc8guru]

Is it possible you got some bad gas? I have had this happen to myself and several of my previous customers. Just for as quickly as this came on I was wondering if maybe you filled up the tank and then the problems started.Just a thought.

[Too Cold NB1.8T]

Anything is possible but bad gas being the problem is very unlikely, here is the reason why:

Bad gas would not choose only some of the cylinders to attack, it would affect all cylinders and it seems that the misfires are only in two cylinders.

[First_bug]

After exhausting everything else I finally pulled the head. I think the PO must have had a valve job done before. Misc nuts and bolts were missing as I took it apart. Once I got the head off the cause was obvious.

The head looks like it was attacked with a hammer. There's a piece missing from one of the exhaust valves on the #2 cylinder. Characteristic valve dings in the pistons.

Looks like some valve and head work in the near future.

I can't believe this after we drove it for only 110 miles.

Pictures to follow. I'm posting this from my iPad.

[First_bug]

Do you think the head is still salvageable? I'm taking it to a machine shop on Monday.

[NewBeetleMechanic]

To be honest, your going to gonna need a new engine.

[dhc8guru]

Mother of god! what did they do, drop a box of hex-nuts down the intake? Effin shade tree mechanic screwed that up. The pistons weren't dinged by the valves, something dropped down into the combustion chamber.

You could salvage a good used head and have it checked out by a head rebuilder, bolt it on and see how the engine runs. But I would towards Newbeetlemechanic's suggestion and get another engine preferably used as rebuilding that engine or buying a new rebuilt engine could get pricey. Possible more than the cars value.
Sorry I would be pretty pissed at that seller and would definitely call him and chew a$$. He knew it was a problem.

[FarrisK]

Looks like they lost the timing belt previously, and just did the bare minimum to get it running again.

[simonsi]

My guess is that the piece from the No2 inlet valve has been in and out of each cylinder via the inlet manifold before finally being expelled down the exhaust. Either way you should check downstream for damage to the turbo as there has clearly been loose metal in each of the bores from whatever cause.

She may well run fine with just a new head, the piston marks don't lok pretty but don't look terminal. You should visually inspect the bores by moving the pistons down to check the is no scoring from debris, the major impact piece is too big to get down the sides of the pistons but the may have been some smaller fragment(s) too.

[dhc8guru]

If the cylinder walls and rings are undamaged, I would agree that having the head redone may be possible. I am skeptical of the head damage. The area close to the valves that is damaged could be fractured, creating future problems. Definitely need to have the head magnafluxed. May just need to replace the one bad valve and be done with it.
I also question their being alot of unburned fuel soot built up on the valves. Why? A lot of factors involved but I wonder if the rings or cylinder wall were damaged.

[jason m]

Originally Posted by FarrisK

Looks like they lost the timing belt previously, and just did the bare minimum to get it running again.

i would agree with that. Hope you got a good deal on the car.

[Too Cold NB1.8T]

It does look like someone has been in there before, someone who's middle name is Twit, that head appears to have the same type of damage in every combustion chamber and I doubt that it is due to broken valve pieces bouncing around in there.

It was probably going bad when you bought it due to abuse and/or a moron with a tool set, I would definitely replace that cylinder head, it might be a good time to prep. the cylinders and replace the pistons and rings, also, replace the piston rod hardware with ARP etc.

I would not take any shortcuts with parts or machine work, use factory gaskets and/or high quality parts, cutting corners will likely result in you having more unwanted problems.

[First_bug]

$750 in work on the head (8 bent exhaust valves) among other things. The damage to the pistons was caused by the piece of valve from #2 cylinder.

Very carefully sanded down the rough spots in the pistons. Coverd the entire head in tape and only opened small holes where sanding, plus used a shop vac, to keep dust out of engine. They looked reasonably good.

Obviously the PO had some head work done before. Maybe it was a junk yard pull, i dont know There were mousing nuts, screws, and boken electrical connectors. Several trips to the vw parts dealer replacing missing or boken parts and it's much better,obviously, than when I picked it up. New head gasket set, new head bolts, vw antifreeze. After a weekend of reassembly we started it today.

We've now put over 75 miles on it and so far so good.

No sign of leaks, no codes, everything running normally. Now maybe we can finally enjoy the car for a while.

[D2Beetle]

Glad to see that you got it running!

[simonsi]

Originally Posted by First_bug

$750 in work on the head (8 bent exhaust valves) among other things. The damage to the pistons was caused by the piece of valve from #2 cylinder.

Very carefully sanded down the rough spots in the pistons. Coverd the entire head in tape and only opened small holes where sanding, plus used a shop vac, to keep dust out of engine. They looked reasonably good.

Obviously the PO had some head work done before. Maybe it was a junk yard pull, i dont know There were mousing nuts, screws, and boken electrical connectors. Several trips to the vw parts dealer replacing missing or boken parts and it's much better,obviously, than when I picked it up. New head gasket set, new head bolts, vw antifreeze. After a weekend of reassembly we started it today.

We've now put over 75 miles on it and so far so good.

No sign of leaks, no codes, everything running normally. Now maybe we can finally enjoy the car for a while.

Good result!

[simonsi]

Originally Posted by Too Cold NB1.8T

...and I doubt that it is due to broken valve pieces bouncing around in there....

The indents in the pistons and cyl head are all the same size and some are the same shape as the missing part of the No 2 valve in different orientations. The damage occurs only in those areas as they are where the head and piston come close enough to impact the piece between the piston and head,

No driving abuse could cause that damage, it would have to be very careful mis-use of tools and that still would not explain why the some indents are the same size and shape as the missing valve fragment. Add that together and it had to be the missing piece causing the damage.