TDI90 ATL EGR and turbo removal

N

nod

Member
I recently bought a TDI90 with 140,000 on the clock - no service history. The car is down on power and fuel consumption is terrible ( around 30 in town and b roads, mid 40's on motorway at 70). I've decided to give it a full on service to include cleaning the egr and turbo - started this today and its more tricky than expected. So, some advice please if you've done it.

I'm using this guide


ATL turbo removal

But i'm finding the space behind the engine is super tight and i can't get to the nuts to undo the EGR cooler, its taking for ever and i'm worried about rounding nuts and shearing things. I'd appreciate advice on how to make more space to work in - I've taken off the air duct above engine, can i undo some mounts? Appreciate a link if possible.

cheers
 
Support the sump with a jack with a piece of wood between - that will allow you to rock the engine forward after removing the engine mount. The turbo oil return is not easy to reach, even with the engine pushed forward. The EGR cooler should be easy to remove, no heat and secured with Allen bolts. The difficult part will likely be the exhaust to manifold/turbocharger nuts. If they won't move, use a nut splitter, if there's room. Use G052112A3 when you put the same back together; this will make subsequent removal much easier.

RAB
 
There is enough play in the driveshafts etc to be able to undo the bottom dogbone mount and also the drivers side engine mount and move the engine forward a few inches on a trolley.
 
Hi guys I'm back on the task of getting to the turbo today, engine mount drivers side off and doggone off, slightly better access. Should I be able to get to all the nuts and bolts from above? Cheers
 
An update, I got everything off egr, anti shudder valve, inlet manifold, but not the turbo, couldn't shift one nut. So, I'm going for a Mr muscle decarbon to free up the turbo vanes as they feel stuck/stiff. Suspect that might be part of the story for lack of power. Also failed on the diesel filter swap out as I didn't have proper hose clamps. Egr and inlet pretty gunged up with carbon, all clean now. Will update after the Mr muscle treatment....
 
Ps the Mr muscle treatment will be done with the turbo in place on the car, by shoving a tube down the egr connection hole, on the hot , iron side of the turbo.there are plenty of YouTube videos showing how it's done. I'd prefer to do it properly, but as I can't shift the nut, it's second best option....
 
I wouldn't spray Mr Muscle into a turbo! Caustic and bearings don't go well together! Isn't the turbo integral with the manifold on a 90? Use a nut splitter.

RAB
 
thanks tdiquattro, i'll take a look and see if i can manage to get the cold side off, thanks spike and RAB, i've downloaded the turbo cleaning guide before and that was my intention to follow that guide, before i got stuck. I'll give it a go if i can get the coldside and VNT off, cheers
 
It's just the m6 bolts (x6?) The ones behind the "snail" are super tricky, then a tap with a mallet to break the seal.

When you refit you need to align the vnt vanes, and there is a small raised dot on the casting to align the halves.

I put loctite on the bolts just in case.
I used penetrating oil spray to clean the mechanism.

Good luck
 
thanks for the advice nige. i tried to take off part of the turbo with the rest left on the car, i failed. couldn't get to the tricky ones behind the snail very well, and thought they looked very difficult to get back on - so everything came off, eventually.used permatex loose all, and it released some of the nuts i was struggling with. all back together now and sounding good, the turbo is clearly spinning up much better and alot of carbon has been blown through and out the exhaust. can't move the car yet though, fluid leak at the clutch slave, but thats another story...........

if anyone is thinking of servicing the turbo i'd recommend taking the whole thing off if you can. i found that the problem with mine was rust build up inside the cast iron casing, rather than carbon build up. i think it must have been jamming the ring mechanism that works the vanes. it takes a bit of 'tapping' to get the turbo apart after the 6 bolts are removed, but from there on its fairly easy to dismantle the inner workings of the turbo, no tools needed. be very careful if you take it apart as the rollers are small, easy to lose and can't be replaced. also scratch some marks on the outer casing before taking to bits, that will make it easier to put back together.

for anyone else doing this definitely release the left engine mounting (3 bolts) with the engine supported on a jack and block of wood, this makes access to the back to the engine much easier, once the engine is lowered and forward. its still not great though.

cheers.
 
ps, for anyone following this thread - once i got the right hose calmps - £6 off ebay, the diesel filter swap out was easy, and the old filter was jet black - check yours if its not been done. my plastic drain screw was snapped off and leaking, replaced with an excellent custom made one from deproman. car now starts first turn instead of taking ages.
 
You must log in or register to reply here.
Back
Top