Main/Rod bearings

[Dmax15]

Have an 01 1.8t in an A4 quattro with 104k miles that I got for my girlfriend and the same day it developed low oil pressure and 20 mins of driving with the oil light flashing. It came to a stop and I went and picked her up with a tow dolly. Started it up once I got it back home and after a minute of idling it developed a loud knock which sounds like rod bearings are out. I know it has the sludge/low oil pressure issue, took valve cover off and burnt oil/sludge all over it. My question is, can the rod bearings be rolled in after I drop the pan or will it be required to pull the motor and a rebuild? I'm thinking about doing main and rod bearings after dropping the pan if this is possible, also clean the oil pump and screen of course. Any help would be greatly appreciated, I'm ready to get the ball rolling so we can get the car back on the road. Also, any recommendations on where to get parts would help, I'll go straight to a vendor on here if they have the parts I'm after.

[Mike@PureMS]

If you're planning to do a rebuild, you should get everything cleaned first. After you get the block cleaned have the journals and mains measured. You'll likely need new bearings, but you can't determine if you need oversized bearings until after everythings inspected first.

[Dmax15]

Thanks for the info, I talked to a local vw tech and he said its not worth it to rebuild most often. He said there is usually a crack in the block which he hasn't been able to find while its torn down and clean but once assembled and rebuilt it shows up so they put a good used motor in it anyways. Some other symptoms of this motor is oil running down front of block and some oil in the coolant tank, there is no water in the oil though. I may just look for a good deal on a complete long block for a replacement if this is the case.

[quaTTro_225]

Since we are on the subject, What are the sizes of the rod and main journals on a 1.8t AMU code?

[Dmax15]

So I've got an 01 long block to swap in, its from a car with a manual transmission and the car its going in has an automatic. What will need to be swapped to make this work, the wrecking yard told me I'll need to swap the flexplate and also balancer from the front off the old motor to make it work, is this correct?

[ross1]

I see no correlation between a potential cracked block and worn rod bearings.
Provided you can remove the oil pan with the engine in place there is no reason you couldn't change the rod bearings and "roll" the mains into place if the caps can be removed.
My concern is the crank will be damaged. If not measure it and use the appropriate bearing size.
FWIW, I've been there in a similar situation with a neglected engine that finally wiped out the bearings. First time in it was fresh .001 OS bearings to compensate for crank journal wear and buttoned it up. Mine was engine out and I regasketed while there. Built up sludge and deposits were disturbed and circulated through the engine. I changed oil filters every 500 miles half a dozen times.
Enough crap made it around the engine and through the oil pump to wear it and the new bearings quickly. Soon after I had the flickering oil light at warm idle.
If it weren't for the fact that the engine was so full of crap I'm convinced the repair would have lasted far longer. I eventually replaced the crank along with all the bearings and oil pump after the filters showed the debris to be cleaned up.
Short version; Bearings worn from high miles but crank okay, refresh bearings and be done. Filthy neglected engine with a knock; rebuild or short block along with thorough cleaning of other componenets.

[Dmax15]

I see no correlation between a potential cracked block and worn rod bearings.
Provided you can remove the oil pan with the engine in place there is no reason you couldn't change the rod bearings and "roll" the mains into place if the caps can be removed.
My concern is the crank will be damaged. If not measure it and use the appropriate bearing size.
FWIW, I've been there in a similar situation with a neglected engine that finally wiped out the bearings. First time in it was fresh .001 OS bearings to compensate for crank journal wear and buttoned it up. Mine was engine out and I regasketed while there. Built up sludge and deposits were disturbed and circulated through the engine. I changed oil filters every 500 miles half a dozen times.
Enough crap made it around the engine and through the oil pump to wear it and the new bearings quickly. Soon after I had the flickering oil light at warm idle.
If it weren't for the fact that the engine was so full of crap I'm convinced the repair would have lasted far longer. I eventually replaced the crank along with all the bearings and oil pump after the filters showed the debris to be cleaned up.
Short version; Bearings worn from high miles but crank okay, refresh bearings and be done. Filthy neglected engine with a knock; rebuild or short block along with thorough cleaning of other componenets.

I don't see a correlation between the two either but there are other symptoms, and the fact that I was told it was very very common for the motors with the sludge issue to have a crack in the block by a VW mechanic was enough to turn me away from trying to do anything with the current engine. I've got another motor now which is sludge free, I just need to know what needs to be transferred from the current motor with an automatic to the replacement motor which was a manual. Also, any bolts or anything that will need to be replaced for the swap.

Is there some sort of timing belt kit for this motor with water pump, serpentine belt, gears and coolant? I thought I found something like this but cant find it again, would like to do it while the motor is out.

[GR-RALLYE]

I don't see a correlation between the two either but there are other symptoms, and the fact that I was told it was very very common for the motors with the sludge issue to have a crack in the block by a VW mechanic was enough to turn me away from trying to do anything with the current engine. I've got another motor now which is sludge free, I just need to know what needs to be transferred from the current motor with an automatic to the replacement motor which was a manual. Also, any bolts or anything that will need to be replaced for the swap.

Is there some sort of timing belt kit for this motor with water pump, serpentine belt, gears and coolant? I thought I found something like this but cant find it again, would like to do it while the motor is out.

http://www.ecstuning.com/Audi-B5_A4-Quattro-1.8T/Search/Timing_Belt/ES1342/

I believe all you would need to do is swap the cranks. I'm not entirely sure on this though.. If you do I would put a new oil pump in there.

The only things I would replace while you got the engine out is misc seals, timing belt kit, crank bolt (if you take it off, cant be reused), coolant, tstat, waterpump... pretty much everything in the t-belt kit

[Scotty@Advanced]

Check with your dealer at one time Audi was covering these engines for oil sludge under warranty.