replacing the intermediate shaft bearings

[rabbitman]

i haven't seen my bearings yet but i just found a pile of bearing bits in my oil pan and im gettign low oil pressure.
Im going to see if i cant remove the majority of the engine, if its those bearings, (or the rear one as i recall it was damaged on install) and get a shop to do it...
even then i dont know how they do it... it seems like a near impossible job to do.

If it really was damaged on install that might explain something..........hopefully the oil pickup screen caught the big chunks and the filter caught the rest. What all gets checked might depend on why the bearing fell out, like if it was from low oil pressure then yes I'd check everything but if it was from knocking it halfway out putting the shaft in then I'd just install a new bearing.

[vanbcguy]

If the IM shaft bearings are indeed gone then I wouldn't bother checking the other bearings. What's the chances that more than one bearing fell apart at once?

EDIT: If it was low on oil pressure then it would make sense to lose all or most of the bearings at once, but a pre-damaged bearing won't hurt the rest provided there's still pressure.

IM bearing failures are super common on these engines.  The timing belt gets overtightened and then the bearing fractures and flakes away.  The pieces get dumped in to the oil pan, but you've got a screen and a filter there.  The low pressure is generally caused by the oil leaking around the IM shaft bearing, but it frequently doesn't mean death to the other bearings in the engine.

Generally the IM shaft bearings fail due to a problem that is totally external to the rest of the bearings, so it's a fairly reasonable approach to just replace them by themselves.

--EDIT: spelling

[92EcoDiesel Jetta]

What's the best way to check the condition of the IM bearings short of taking it out and measuring it? Oil pressure? Oil analysis? As to belt tension, can you use a tensioner from a TDI which has an automatic tensioner built in? That would eliminate over tensioning.

If the IM shaft bearings are indeed gone then I wouldn't bother checking the other bearings. What's the chances that more than one bearing fell apart at once?

EDIT: If it was low on oil pressure then it would make sense to lose all or most of the bearings at once, but a pre-damaged bearing won't hurt the rest provided there's still pressure.

IM bearing failures are super common on these engines.  The timing belt gets overtightened and then the bearing fractures and flakes away.  The pieces get dumped in to the oil pan, but you've got a screen and a filter there.  The low pressure is generally caused by the oil leaking around the IM shaft bearing, but it frequently doesn't mean death to the other bearings in the engine.

Generally the IM shaft bearings fail due to any problem that is totally external to the rest of the bearings, so it's a fairly reasonable approach to just replace them by themselves.

[Rock3tman]

+1 vanbcguy       

My IM bearings in my 1983 turbo CY engine were completely flaked apart with a pile in the bottom of the pan.  After 221K miles, both the main and rod bearings were smooth, measured for NO oversize, and had just a slight discoloration.  Cylinder bores needed a full .5mm to restore.  The oil used was generally Delo400 10-40 with a sketchy change interval.

[rabbitman]

What's the best way to check the condition of the IM bearings short of taking it out and measuring it? Oil pressure? Oil analysis? As to belt tension, can you use a tensioner from a TDI which has an automatic tensioner built in? That would eliminate over tensioning.

To check 'em I just pull the shaft and look at the bearings and see it they're flaking at all.

I'm not sure on this but aren't TDI timing belts way tighter than these IDI belts?

[nathan_b]

not much tighter if at all, but they have auto tensioners and lots more rollers.

[damac]

On my jetta I was lucky and didn't have to remove that passenger side back mount to pull the intermediate shaft completely out when doing a timing belt job.  I already saw the bits in my oil after I got the car home and when I pulled the shaft there were tons of bits I could pull off with my fingernail, all of it became dislodged once I disturbed it.

What sucks for me though is I believe I am teetering on low oil pressure still after replacing.  My high end buzzer keeps going off so I disconnected it.  At first I thought it was acting up because it would go off then hang and go away when blipping the throttle until the next time, usually on a tight high speed turn.

I put a manual gage in and I think I get less than 20 when hot idling, that is with the port in the head.  It goes up as I put more pedal into it approaching 40+ at 3000 rpm.

Now I am kicking myself for not putting in a windage tray and perhaps the bigger oil pump(not sure what i had in there).

I would love to do that but my problem is I didn't use an oil pan gasket and used some right stuff and have no idea how the hell to seperate the halves  now.

[nathan_b]

15-20 hot idle with 40psi hot at 3krpm is not terrible.

[vanbcguy]

15-20 hot idle with 40psi hot at 3krpm is not terrible.

^^^ true that.

I've had plenty of engines with less pressure than that.  Less than 10PSI hot idle after a freeway run is about when you know you're starting to have to think about a rebuild.  20PSI is golden - you're doing great.

Sounds like you might have a bad pressure sensor - I can't recall what the actual pressure requirement for the high sensor was but I'd bet Vince W. has it on his site.

[R.O.R-2.0]

my old 1.5TD at hot idle, had just enough oil pressure to bring my autometer gauge off the peg (6-8psi i would guess) and about 40-50 cruisin down the road..

and i ran the hell out of that thing. ended up killing it from too much boost. head almost left the block. cracked 7 head bolt bosses..

[92EcoDiesel Jetta]

I wish it's that easy. On my Jetta, it hits the inner fender. The engine has to come out or at least up.

To check 'em I just pull the shaft and look at the bearings and see it they're flaking at all.

[92EcoDiesel Jetta]

On my jetta I was lucky and didn't have to remove that passenger side back mount to pull the intermediate shaft completely out when doing a timing belt job. 

Please explain what you did to pull the IM shaft out. What year is your Jetta?

[rs899]

On the Mk2, the IM shaft can be removed through the right wheel well if you remove the front and back mounts

[92EcoDiesel Jetta]

On the Mk2, the IM shaft can be removed through the right wheel well if you remove the front and back mounts

Is that so you can lower or raise the engine? By how much?

[Mark(The Miser)UK]

15-20 hot idle with 40psi hot at 3krpm is not terrible.

^^^ true that.

I've had plenty of engines with less pressure than that.  Less than 10PSI hot idle after a freeway run is about when you know you're starting to have to think about a rebuild.  20PSI is golden - you're doing great.

Sounds like you might have a bad pressure sensor - I can't recall what the actual pressure requirement for the high sensor was but I'd bet Vince W. has it on his site.

From the official VAG mag, I think this holds true for  hydro as well, but not entirely sure:

For mech heads, 'pressure at filter for TD or n/a is 2 bar at 2000rpm. 0.3 bar sensor on head must operate between 0.15 and 0.45 bar, at head'
 So from that I deduce minimum allowable pressure at head is about 2.2psi any time