removing downpipe

[nicks90]

hi folks,

having a stress about removing the downpipe / CAT on my 300tdi 90.
i have a replacement downpipe to fit so i can ditch the stupid catalytic converter and free up a few more snorters from the engine.
BUT
i came to undoe the 3 bolts that hold it onto the bottom of the turbo and could not for the life of me get them undone. 9/16" socket wont fit and a 15mm socket spins.

and there isnt enough room to get Mr Angry (the grinder) in there to "sort" the bolts either. Plus i would then be left with the threaded bits stuck in the turbo side of the flange to drill out.
does anyone have any ideas or tips on getting these bolts undone. As per usual with exhaust related nuts and bolts - 10 years of use/abuse and exposure to alot of heat from the turbo 6" away has rendered them quite interesting. not sure wd40 will do the trick.

[Matthews]

Have you tried a 14mm wall drive socket , is your 15mm a 6 point or a 12 point ? , quite often a 12 point will spin whereas a 6 point will remove the nut, if you get totally stuck give me a bell.
Matthew

[dave willard]

Mine is 95 suggest y check to see if MOT test will allow no cat, as I think 95 is last year y can do this not certain though
Had the same problem on mine as suggested long reach socket metric & imperial undersize hammering it on.try it on hot engine(plasters needed)
The complete turbo is not very hard to remove, the inlet manifold is easy to remove first then you can see the exhaust studs/nuts which can be soaked in plus gas ( the studs usually come out of the head)
The oil drain pipe is removed at the block (I cut down an open ended spanner for the to get movement)
The feed pipe can be seen on the tubo top
When doing this lot you can clean the inlet manifold it will be full of congealed oil It goes without saying that the oil feed pipe needs to be very clean to avoid getting dirt in, which will cause damage, when refiting pour oil into the turbo before putting pipe back as per manual I have an engine on the bench if you want sus out DAVE

[dave willard]

Hi
forgot to mention that I hade to make a brecket to hold the new exhaust pipe to the bell housing bolt using exhaust clamp & steel strip

The reason I did this is that my original cat had a flexible section, without this the pipe & manifold bolts can be strained having to support a longish section It also seemed to cut resonance down
DAVE

[dave willard]

Hi I have checked the turbo to pipe stud length on a spare turbo it is 25mm which may mean a standard socket is too short

Are you attacking these nuts from under the engine using a couple of ½ inch extension bars there is a straight run in doing this

I found that most sockets have a 2/3 mill chamfer to help socket slide on, in cases such as this I remove this with an angle grinder keeping the socket wet cooled to prevent blueing, this gives a bit more grip where its needed it will also sharpen a socket

I have also put a jack under the T bar using a plate to give a bit of upward load forcing the socket in place, because when a socket slips it is usually pushed off a little bit

Hope this helps

[nicks90]

cheers for the advice guys,

theres plenty of room to get to the bolts from above - rather than struggling underneath with loads of socket extensions, all i did was remove the intercooler pipes and the water bottle / squirty pump. That leaves a nice big gap between the turbo and the inner wing.
I am just having problems with the socket rounding the nut.

But matthew is right i think - must try a 6 sided socket instead of the 12 sided.
I'm just worried that if the bolt shears off under brute force, a quick 20 minute job to undo 3 bolts and 2 clamp bolts from the other end - will turn into a weekend drama removing the turbo and drilling snapped studs out of the holes, and i can guarantee an exhaust stud will snap off in the head to really piss me off.

[dave willard]

Hi
As you have room I have a nut splitter somewhere not used it for years if you let me know I will look for it & using spare turbo see if it will fit

Have not tried it or ever used one but a Dremmel may be small enough to get in to cut the nut if y can borrow one

The main reason for going underneath is to load the socket with the jack I strongly recomend this together with grinding the socket, it may help prevent shearing the stud as have a lot more control on the force being used

DAVE

[dave willard]

Hi again

When using undersize socket with variouse flats if you dont have to hammer the socket onto the nut it probably wont work which is why going underneath is easier espacially the nut nearest the block just belt the extention / bar
dace

[Bobcat]

Nick if a standard length socket will fit,if your not bothered about chewing the nuts up or snapping studs.
Go to machine mart and buy (deep breath) a set of IRWIN bolt grip sockets.They will undoo anything,beleive me.They dig into the bolt/nut.The harder you turn the tighter they grip.
There are two sets covering sizes from3/8 to16mm and5/16 to19mm.
The catalouge codes are
040214678 and 040214679