200 Tdi Rebuild - Tight Bearings?

Hello all, I'm currently in the process of rebuilding my 150,000 mile 200 Tdi.

I've fitted new standard size shell bearings and standard piston rings to the original pistons, everything fits well.

This evening I refitted the pistons - lubed up the bearings and torqued up to what Haynes specifies.

I noticed that with two pistons fitted, the engine was pretty stiff to turn over by hand. Manageable with my 2ft breaker bar, but stiff all the same.

With all four pistons fitted and torqued up, I can't get the engine to turn by hand. However it does spin freely on the starter motor - nice and smooth and doesn't appear to be struggling.

I want to put this down to the new parts bedding in, and it will eventually loosen up with use.

Is this normal? Or is something wrong?

Cheers

Try tapping the big ends with a soft faced hammer, tap each one 3 or 4 times.

Soloby Rob said:

Try tapping the big ends with a soft faced hammer, tap each one 3 or 4 times.

Click to expand...

Thanks for the tip, will give this a go tomorrow morning.

did you gap rings ,in bore before fitting to piston ,con rod caps right way round ,with head off it should turn with large screw driver wedged between rear crank boss and flywheel locating pin ,you can check bearings to see if shiney marks show tight spots

jamesmartin said:

did you gap rings ,in bore before fitting to piston ,con rod caps right way round ,with head off it should turn with large screw driver wedged between rear crank boss and flywheel locating pin ,you can check bearings to see if shiney marks show tight spots

Click to expand...

I didn't gap the rings, no. Assumed they would be OK. When knocking the pistons in they didn't feel tight though, they slide fairly easily up and down when not attached to the crankshaft.

It's got to be something to do with the big ends, as if I loosen off the nuts slightly the engine turns over more easily.

Which way round are the con rod caps supposed to go?

At the moment, as you lie under the vehicle with your feet at the front, the numbers on the con rod caps are the right way up on the left hand side of the caps.

If that makes any sense

just out of interest how much has it cost for the parts??

ive got a spare tdi in my workshop, been thinking of rebuilding it for some time.

you may be lucky fitting new rings in old bore but rings arent necessarily the right size and often need filing to get the right gap ,its important especially when engine gets to temp, caps are unique to each rod ,anti rotation notches sit on same side ,numbers on rod and cap are on the same side,when you rebuild an engine cylinders are bored out to piston plus clearance size which on a tdi is 1 thou,rings are gapped to fit bore between 11 and 18 thou,pistons are not exactly round till upto temp

jamesmartin said:

you may be lucky fitting new rings in old bore but rings arent necessarily the right size and often need filing to get the right gap ,its important especially when engine gets to temp, caps are unique to each rod ,anti rotation notches sit on same side ,numbers on rod and cap are on the same side,when you rebuild an engine cylinders are bored out to piston plus clearance size which on a tdi is 1 thou,rings are gapped to fit bore between 11 and 18 thou,pistons are not exactly round till upto temp

Click to expand...

I've got all the caps on the right rods, and the right pistons in the right holes.
The anti-rotation notches should all be aligned as far as I know, will double check tomorrow.

How can I tell whether the shells I've been sent are the correct size?

it will have std etched on steel backing side or +10 if oversize

pete23 said:

just out of interest how much has it cost for the parts??

ive got a spare tdi in my workshop, been thinking of rebuilding it for some time.

Click to expand...

So far, under £150 including a head skim

May have to 'shell out' another tennar tomorrow if the shells I've been sent turn out to be the wrong ones!

jamesmartin said:

it will have std etched on steel backing side or +10 if oversize

Click to expand...

Ok - from what I remember, the shells just had a code on the back.

Is it possible that the bearings will loosen up by themselves as they are 'run in'? Or am I at risk of seizing the engine if I was to run it in its current state?

it would be locked solid if bearings were +10 ,although could be poor parts once tightened you should be able to move rod side ways a little proving its not tight

Langers said:

Ok - from what I remember, the shells just had a code on the back.

Is it possible that the bearings will loosen up by themselves as they are 'run in'? Or am I at risk of seizing the engine if I was to run it in its current state?

Click to expand...

If they are std shells (and you have the caps on right way) you just need to give the big ends a good belt with a soft faced hammer, if the are +10 on a standard crank you'll need to get em changed.

Soloby Rob said:

If they are std shells (and you have the caps on right way) you just need to give the big ends a good belt with a soft faced hammer, if the are +10 on a standard crank you'll need to get em changed.

Click to expand...

Ok then, that'll be the first thing I try tomorrow.

If it's still tight, I'll send the shells back to Paddocks and get a genuine set instead.

Cheers for all the help chaps

Sorted it

Turns out I had all of the bearing caps the wrong way round...

With all them the correct way round I can spin the engine over with one hand now,

Ah well, lesson learned

Thanks all - stand by for further issues as I replace the cylinder head