Rod Bearing, ALH

Kurt13rager

Active member
Joined
Jul 19, 2013
Location
Manassas, VA
TDI
01 Jetta
Newbie here, first VW, first TDI. I bought a 2001 Jetta TDI two days ago, fully aware of a rather loud knocking engine. The PO said that he was commuting on the highway to work one day and all of a sudden he heard the engine knock, followed but a loss of power. He said he pulled over and got it towed to a garage. He said he didn't want to sink any money in to the car and would rather sell it as is. I inspected everything and let him start it but only for a few seconds. I decided it was too good of a deal to pass up, so I bought it. After I got it home, I pulled the valve cover and inspected the cam and everything looked good. This morning, I dropped the oil pan and found that the #3 cylinder rod could easily be moved with my fingers. I pulled the cap and found no bearing left at all. After sifting through the oil and pan, I found some debris. I inspected the crank and everything looks fine.

Does anyone see any problem with simply installing all new rod bearings and closing everything back up? Am I missing something here? Any help, guidance, is greatly appreciated.
 

Kurt13rager

Active member
Joined
Jul 19, 2013
Location
Manassas, VA
TDI
01 Jetta
I wasn't sure. There is virtually no physical sign of wear or gouging on the crank. I suppose I was just hopeful that the bearing was only gone for a very short time and that the crank could be ok.
 

jimbote

Certified Volkswagen Nut
Joined
Jul 10, 2006
Location
spiral arm, milky way (aka central NC)
TDI
Tacoma 4x4 converted to TDI
only way to know for sure is to check for out of roundness and tolerance by measuring the journal with a micrometer....these cranks do hold up surprisingly well to oil starvation so you may have dodged a bullet ....the rod also needs to be measured for out of roundness and tolerance but that easier said than done with it still in the block ;)
 

Kurt13rager

Active member
Joined
Jul 19, 2013
Location
Manassas, VA
TDI
01 Jetta
That's what I was planning to do. Does anyone know what the specs are supposed to be? I'm going to pick up some plastigage as well. Thanks for the replies so far.
 

Nutsnbolts

Vendor , w/Business number
Joined
Nov 1, 2001
Location
Weare, NH
TDI
2000 Jetta, Silver Arrow
According to the Bentley, the crankshaft specs are:

Main journal: 54.00mm/2.1260"

Main bearing radial clearance (checked by Plasitgage) should be 0.03-0.08mm/0.0012"-0.0031", with a wear limit of 0.17mm/0.0067"

Connecting rod journal: 47.80mm/1.8819"

Connecting rod radial clearance (checked by Plastigage) should be 0.01-0.06mm/0.0004"-0.0024", with a wear limit of 0.08"/0.0031"

Make sure that you have decent measuring tools for this. The Plastigage method is acceptable according to the Bentley, but if you trust your micrometer, then the math is pretty easy too.

As Jimbote said, these cranks are pretty stout, and I've seen several with well over 200,000 miles on them that still measured within servicable spec. The only time I've ever had to turn one (and it was the only one!) was when a bearing spun from oil starvation.

-Rich
 

Nutsnbolts

Vendor , w/Business number
Joined
Nov 1, 2001
Location
Weare, NH
TDI
2000 Jetta, Silver Arrow
It wasn't my spun bearing (thankfully!) It was from when I had my shop. Read on...

The oil pan on the car was wiped out on I89 in Vermont on a snowy day, and the customer had decided to continue to drive to the nearest service station rather than risk waiting for a tow. It was about 10 miles with little to no oil pressure. The shop put a turbo and an oil pan for considerable money, and sent him on his way, and a short time later he began to hear a loud lower-end tick-tick-tick at startup. The #3 main bearing had been spinning in the block until the oil pressure came up.

-Rich
 

Kurt13rager

Active member
Joined
Jul 19, 2013
Location
Manassas, VA
TDI
01 Jetta
That's what happened with the PO of the car I just bought. When I pulled the pan I noticed there were a couple small cracks in it. I just don't get it. Pans are a lot more reasonably priced then a lower end rebuild. New bearings should be here tomorrow along with a timing belt kit and plenty of oil.
 
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