Seized wastegate???

[A2TD]

Hi , I'm knew to the board.  I have an 87 TD, I'm pretty sure the wastegate actuator is seized. I'm curious, does anyone have an effective technique of unseizing the wastegate without removing the turbo from the car. Any insight would be greatly appreciated. Thanks

[fspGTD]

Is it a garrett or a KKK turbo?  1.6lTD, MF engine code?

[vwmike]

Is it stuck open or stuck closed?

[A2TD]

Its a KKK, I'm assuming its stuck open as I'm not geting a whole lot of boost. But I don't know for sure. Any ideas ?

[fspGTD]

Your K24 wastegate could be stuck or you could have a badly corroded wastegate valve seat.  I found mine was both a little bit stuck and had a leaky valve seat.  To restore it really well will require removing the turbo, separating turbine housing from center section, and finally removing wastegate from turbine housing.


You might consider renewing the bearings in the center section at this time (I sell a very complete and high quality rebuild kit for this turbo with a 360 degree thrust bearing upgrade, new turbine housing bolts, etc - let me know via IM if you're interested.)  Chances are your 25 year old turbo is still on it's original bearings.  IMO, it's a good idea to replace them with new (actually, make that better than new with a 360 degree thrust bearing!)

With the turbo apart, you can properly inspect and probably successfully clean and restore the sticking wastegate valve guides.  (Possibly restore a corroded/leaking valve seat as well with valve grinding compound).  Here is what it will probably look like behind the wastegate:

Thoroughly clean out all the carbon and junk around the valve stem using a solvent like brake parts cleaner.  Press the wastegate valve in and let it relax outwards a few times and assess it's condition.  Hopefully you can get it moving with a little bit of force as needed to break up the junk.

Then with it pressed in fully, plug the wastegate boost pressure port and spray some penetrating lubricant flooding the opening around the valve stem/valve guide (I used GM heat valve lubricant which has moly in it, but you might also take a look at a product called "mouse milk").  Then let it relax and extend.  The suction inside should draw the penetrant/lubricant into the valve guide.  To push the lubricant out, plug the boost connection and compress the wastegate valve.  At first, it will come out totally black and nasty.  Repeat the process until the wastegate operates freely and penetrating lubricant comes out clean.  You will be amazed at how much more freely the wastegate work after you do this!  I was able to get mine sliding freely in and out, like new.  (Good for another 25 years perhaps...)

Check out this thread for additional info:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1841

[A2TD]

Is there any way to unseize the valve without taking the wastegate off the turbo............I have a feeling if I try things will break. I read in the link you gave that one guy had the exact same problem and uncrimped the wastegate cover and freed it up that way. Any ideas??

[fspGTD]

Remove wastegate, use solvent to clean up the carbon behind heat shields and around the valve stem area as much as you can, and squirt penetrating lubricant around the valve stem and let it creep inside.  Then, with the crimped-on can supported in one vice jaw (not supported by the small protruding stud), clamp it down onto the valve head and give it a squeeze.  If that doesn't get your wastegate valve back up and running, I don't think anything will.  And then with it removed you can clean up the old crusty, gummy residue around the valve stem and get it moving without sticking.  The residue around the valve stem is probably the reason your wastegate froze up in the first place.

[andy2]

There is one possible cheap,easy repair.Just take the adjustment screw out of the wastegate's cover.Insert a punch into the cover and use a hammer to try and force the seized valve closed.Now as long as this pump isn't modded then all (which I'm assuming it Is not)you need to do is disconnect the air line heading for the wastegate by removing the banjo bolt on the turbo's housing and just get some washers that will make up for the thickness of the fitting on the end of the line that you just removed and install the bolt with washers again to plug the hole in the turbo.As long as no fueling adjustments have been made then your max boost with the wastegate being closed will be 12-13 psi max which is'nt much more than the 9-10 psi stock pressure.If this works your set and you'll have a bit more power and less smoke than an otherwise stock properly working 1.6td.
Good luck :wink:

[A2TD]

Andy: If I pull the nut and stud off the top of the waste gate, wouldn't hammering downwards cause the wastegate to open even more??? From the pics fspGTD posted ( which is the identical turbo I have) the adjustment screw appears to be right on top of the wastegate valve. I'm not trying to say it doesn't work, I'm just trying to understand how it works. Thanks

[fspGTD]

Andy: If I pull the nut and stud off the top of the waste gate, wouldn't hammering downwards cause the wastegate to open even more???

Andy is right and I think has a decent idea for you here.  Hammering on a punch through the stud hole on the KKK wastegate would cause it to close.  The K24 diaphgram and wastegate valve moves outwards (away from the turbine housing, in a pulling manner) when it opens.  Just be careful not to bugger up those threads if you try this.

Have you considered that your problem may be just a badly pitted wastegate valve seat, and not a frozen valve?  If your valve seat is pitted, it could still leak even if it is frozen in the full closed position.  In fact I found my K24 wastegate valve seat was leaky (working on a fix, but it would require removing the wastegate.)

I'd think the K24 with properly sealed wastegate (good sealing valve seat) would boost up a lot higher than 12 psi with wastegate completely sealed shut, but I haven't tested it on the car yet like Andy2 has.  I have tested the (quite similar) Garret 1.6lTD turbo though, and found it achieved 14psi boost without what seems like a whole lot of fueling when the RPMs were in "on-boost" range.

Andy2 - I'm curious if you are sure that your K24's wastegate is sealing completely when closed, because if 12psi is all it can muster at stock fueling, I wonder a wastegate was put on the turbo in the first place.  12psi isn't not even enough boost pressure to open the pressure relief valve on the intake manifold.

Andy2's idea might be worth a try as a possible quick and dirty fix.  If your wastegate can really is facing straight up with the turbo installed in the motor, there is something else you can try with turbo left installed.  You could remove the boost tube hardline connection and squirt some heat valve lubricant/ penetrsting oil into the boost can and the follow it up with some air pressure to try and force it into the valve stem.  That all might help get if broken free and clean it out somewhat.  As long as the turbo is oriented so gravity would make the oil that is inside the wastegate can puddle around the valve guide, the penetrating oil I'd think would eventually make its way through the valve guide and exit the exhaust system harmlessly, and thus be "self cleaning".

If you try any of this, please let us know how it works, and good luck.

PS - I'm curious to see how your wastegate is mounted in a totally vertical position with can straight up.  I usually recall 1.6lTD wastegates being more horizontally-mounted... got any engine compartment pics?

[andy2]

Yes Jake I forgot,I did have to plug off the BOV to obtain I believe 13-15psi.

[A2TD]

Thanks alot guys    My wastegate is mounted horizontal. I'll give it a try,
It could be the turbo is pooched in general.