TDI has a knock...any ideas?
Moderator: Fatmobile
TDI has a knock...any ideas?
I just bought a wrecked early 99 Jetta TDI. It was a light roll over in a ditch and I got it home and tried to start it and heard a loud knocking in the engine and it started and I shut it right off because it was a solid type of knock. I took the pan off and didn't see anything in the lower end that was causing the knock. The rods were all straight. I thought maybe a cylinder got full of oil and bent a rod. When #1 & 4 were coming up on top, it would hit something on the top end that is pretty solid. I used a ratchet on the balancer bolt and it would stop me dead when I'd roll it to the top. When I first used the starter, it would go past it but by hand it won’t. I talked to the gal that owned it and she said it was lying on its top for about 4 hours and the tow truck guy got it back on its wheels, checked the oil and said it was very low, started it and drove it on the wrecker. She said it sounded good then. Do you have any ideas on what might be the problem or what I should do now? I have worked on a lot of American engines but this is new to me.
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coke
Sounds to me like you got screwed. "Sounded fine when it was driven on the wrecker"
If the pistons are hitting something its most likely a valve. An upside-down condition isn't good for the motor. But I dunno about making a loud knock because of it, unless the cylinders filled with oil and had no place to go when the engine was cranked over so it broke all your rings. Pull the head and see what you are dealing with.
If the pistons are hitting something its most likely a valve. An upside-down condition isn't good for the motor. But I dunno about making a loud knock because of it, unless the cylinders filled with oil and had no place to go when the engine was cranked over so it broke all your rings. Pull the head and see what you are dealing with.
I pulled the injectors out of 1 & 4 and I put compressed air with the valves closed and # 1 piston will move back down in the cylinder, # 4 won't and I hear air bypassing there too so it looks like a valve in # 4 is the problem. How much of a job is it to pull just the head or is it just as easy to pull the engine?
just leave the engine in the car, its easy to pull the pan and head with it in there, unless you want to do other work to the engine, like rear crank seals, or clutch. i would pull the crank too, and check it out, since these diesels have so much power at the low end, its possible that when the car rolled, the engine kept running, but didnt have any oil because it would run to the top of the engine. if this happened, it would definately cause some damage to the crank, cam, pistons, and possibly the cylinder walls.
I just came in from taking the head off. I found the # 4 piston top completely ate up and galled to the cylinder wall and head like a cap so when the piston came up to almost top dead center, it was hitting on it's melted material stuck to the head and wall. That's what the material was on the injector too. It looks like I will be taking the engine out. I wish I'd talked to the tow truck driver about how it sounded. The woman said it sounded good but the way it looks, it has had problems for a while.
I found a TDI that's supposed to be out of a 99 or 2000 Beatle that someone changed the timing belt wrong and belt some valves. I was going to look inside the cylinders with a bore scope. Will it fit in mine? How do I tell exactly what year it is and if it's what I need? It had a cast valve cover and pan and a few other things different. They said it only had about 40,000 miles on it.