1g Turbo help??!!?

[BitAddict]

Hey everyone! I've been looking around for some info on my questions(and am still searching) so if any of you have answers or know where i can get some I would really appreciate the help!!

First of all to give you some background info. I have a 90 talon tsi. basically stock under the hood. I have a mbc and phantom gauge. I started to loose some turbo pressure slowly but surely so i thought my turbo was just on its way out. It finally quit working and i decided to replace my exaust gasket so im in the middle of taking everything off. I checked the turbo for shaft play and there was none. This led me to thinking maybe the wastegate was stuck open(im guessing here). I tried my best to hook up a hand pump to the wastegate. The wastegate did not open. I also checked the blowoff valve and it also did not open like it should.(maybe i checked it wrong but it didnt seem to work) My questions are more about what i should do next... take everything off? If so what should i do to check the turbo? Are there any other stuff I should check now? I for some reason think the turbo is still in good shape but im not sure. I just need some help on what i should do next. If anyone can help I would be extremely greatful!!!!
Thanks for the space!

 

[GTM]

Originally posted by BitAddict

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This led me to thinking maybe the wastegate was stuck open(im guessing here). I tried my best to hook up a hand pump to the wastegate. The wastegate did not open.

I also checked the blowoff valve and it also did not open like it should.(maybe i checked it wrong but it didnt seem to work)

You should be able to remove the push rod from the waste gate lever. If that gives you a problem take the 2 bolts out of the actuator mount and that will relieve the pressure on the rod connect. Once off the waste gate should just flop around.

Now, if you have been putting pressure on the wastegate actuator it "ain't" gonna move, you need a vacuum source the last time I looked. I've not had a reason to check the BOV testing procedure but make sure if it says vacuum don't use pressure.

Cheers,
GTM

 

[BitAddict]

thanks for the responce i am going to try to loosen the actuator arm. you were right about the BOV check it is vacuum but the book says to apply i think just under 12 psi to the wastegateactuator for manual transmissions..??? thats what i tried to do and it didnt budge. the air pump(its like a tire pump) im using can only creat pressure not vacuum so i will test that tommarrow.

 

[GTM]

Originally posted by BitAddict
thanks for the responce i am going to try to loosen the actuator arm. you were right about the BOV check it is vacuum but the book says to apply i think just under 12 psi to the wastegateactuator for manual transmissions..???
...

You are welcome.

Easy test for the wastegate actuator. Pull it off and push down on the body with the rod on the ground. (very very stiff spring) Put you finger over the hose fitting and see which way the air flows when you release.

There is no pump thus the only purssure source could be the intake manifold under pressure, it's been a while since I've tested one for anything else but leaks.

Also check the hose for air flow, someone may have shoved a ball bearing inside to keep it closed and run the manifold pressures up.

Cheers,
GTM

 

[BitAddict]

I took off the wastegate, ac fan assembly, most of the tubing and drained the coolant in between posts. I tried to do what you said to the wastegate but could not push the rod into the wastegate body at all. I could only pull it out. does this seem right or is something broken? i get resistance when pulling on the rod, not pushing in????


"There is no pump thus the only purssure source could be the intake manifold under pressure, it's been a while since I've tested one for anything else but leaks.

Also check the hose for air flow, someone may have shoved a ball bearing inside to keep it closed and run the manifold pressures up"


Im not sure which hose your talking about to check for airflow? this is the first time ive ever fooled with a turbo so please bear with me.

 

[GTM]

Originally posted by BitAddict

...
I tried to do what you said to the wastegate but could not push the rod into the wastegate body at all. I could only pull it out. does this seem right or is something broken? i get resistance when pulling on the rod, not pushing in????
...
Im not sure which hose your talking about to check for airflow? this is the first time ive ever fooled with a turbo so please bear with me.

Grrrrrrr, see what happens when you don't have the bloody parts in front of you. ... ya make stupid mistakes in describing a process. bleah!

And bear with me too please. So stick a small screwdriver through the rod lever hole, cradle between your feet and pull, put you finger over the hose connect and see if the diaphram leaks down. Check the wastegate lever to make sure it is free to move.

The hose that attaches to the wastegate actuator where you placed your finger. If you want to slow the actuator down just put short length of copper tube that you have crushed to just a pin hole... (it becomes a metering jet) that will delay the wastegate opening, yet allow it to maintain the factory settings. If the BOV farts at you then open it up a bit.

Cheers,
GTM

 

[BitAddict]

thats fine dont worry about messing up directions! I checked the wastegate and it drops a little bit at first(assuming it gives just a bit) but then holds so im guessing it is working right. the rod lever is moving smoothly. i suppose i can rule out the wastegate problem. im picking up an o2 socket tommarrow and will be taking the rest of the exaust and turbo off to inspect everything. No more garage time for me tonight its cold as hell out. I'll post what i find tommarrow. Thanks again for the help so far! Have a good night!

 

[BitAddict]

ok well i have everything off except the nuts for the exaust and the oil return line. The book doesnt say anything about needing to drain the oil so i should be alright in just taking off the oil return line? I also forgot to mention some coolant came out of the turbo pipe when i took it off and spilt on the front of the tranny...i dont think i need to worry about that really???

 

[GTM]

Originally posted by BitAddict
...
and the oil return line. The book doesnt say anything about needing to drain the oil so i should be alright in just taking off the oil return line? I also forgot to mention some coolant came out of the turbo pipe when i took it off and spilt on the front of the tranny...i dont think i need to worry about that really???

It may be easier if you remove the "J" pipe from the pan in which case oil will run out so you will need a dishpan. The J pipes are notorious for cracks and not seating so pay attention to gasket faces, gaskets and cracks. New factory J pipe and aftermarket improvements are available, lots of them repaired with cutting the convoluted section out and replacing with proper hose and screw clamps.

Coolant dribbles are to be expected, nothing to worry about unless you didn't drain the system. Radiator petcocks break and seal gets lost, have spares.

Cheers,
GTM

 

[BitAddict]

Yes i was planning on replacing it anyways because some oil is visible around the upper "J" seal. i believe that is the oil return line. Im going to try and take it off from the top to reduce the mess. ill post how it goes tonight!

 

[BitAddict]

well so far two exaust nuts broke off in the head so im giving up tonight. have to take care of that and fully undo the "U" shaped coolant line that wraps underneath the turbo. im about to set my car on fire.

 

[GTM]

Originally posted by BitAddict
well so far two exaust nuts broke off in the head so im giving up tonight. have to take care of that and fully undo the "U" shaped coolant line that wraps underneath the turbo. im about to set my car on fire.

Oh geepers, don't tell me this is turning into the job from hell.

I've written a couple of posts in the last few weeks about broken bolts and studs. If there is enough left a good pair of 3-4" Vice-grips may take them out by rocking back and forth.

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=90999&highlight=drill+good+pick
http://www.dsmtuners.com/forums/showthread.php?s=&threadid=89339&highlight=drill+buy+good

If you want to take this to email it's ok.

Cheers,
GTM

 

[BitAddict]

everything ive ever worked on has become a job from hell! but its fun and ive learned quite a bit from going through it so the experience is worth every penny and every dollar! Ill look over your threads tommarrow when i have to deal with the problem. Im just gunna keep posting on the thread in case anyone else needs reference. i do appreciate all your help so far!

 

[BitAddict]

hey hey sorry about not posting! Ive been trying to get my internet connection to work for the past day and a half.(in the mean time ported exaust mani :] ) I took my turbo apart GTM and both compressor wheels seem to move just fine with no play! I am somewhat stumped... i did find however that where the wastgate hole is in the larger compressor housing has a crack running through it! Im going to post a picture of it and tell me if you think this could be causing the problem. The wastegate doesnt seem like a very good sealant in the first place so maybe the crack has made it 10x worse?!???

 

[BitAddict]

here is the pic of the crack...(sorry its a little blurry) the crack goes from one side of the wastegate hole to the other. i have other pics of the turbo if you want to see them too.

 

[GTM]

Originally posted by BitAddict
here is the pic of the crack...(sorry its a little blurry) the crack goes from one side of the wastegate hole to the other. i have other pics of the turbo if you want to see them too.

Yup it was blurry, thought I saw something going from the bolt hole all the way to the turbine. I would not feel comfortable stating that is your problem, there are pictures on Vfaq.com.

Not a scientific test but I used some molly assembly lube mixed with oil and lubed both of the oil inlet and drain. I then crudely attached a vacuum cleaner using pressure on both intake and exhaust to verrify it was free enough to spin. Duplicated same with suction side of vacuum cleaner before we installed the used replacement. That was for my own peace of mind that it would function which it does quite well.

Cracks are the norm and I have no information that they cause a loss of power, Remember the wastegate is a relief valve to prevent excess boost before the BOV comes into play. Something I'd not thought of which could be a part of your complaints would be a problem in the exhaust system. baffels can break internally and block a passage which would give the turbo too much back pressure. Look for kinks crushed sections etc., not common but still a possibility.

After all is back together we may need to explore other possibilities if this has made no change.

BTW how are the broken studs coming along.

Cheers,
GTM

 

[BitAddict]

Yeah im not really sure what i should do. I might try to replace that section and then do the vaccum test you suggest. everything else looks like its in good shape so im stumped! there arent any places around here who work on turbos so if all else fails ill take it to the dealer. i figured if the turbo went out naturally there would be more obvious signs. otherwise i would not be wasting my time with trying to fix the problem. ill check the vfaq also. i have yet to work on the studs. my father has been out of town and he has a few new bits i plan on stealing :] not sure how my internet connection is going to be but when i move further along ill keep posting updates. thanks again for your time and effort!!!!!

 

[babell2]

If you feel uncomfortable with the amount of cracks in your turbo hot section Forced Performance sells a upgraded new style exhaust section that is a direct bolt up and better than origional. They will also sell an overhaul kit for your 14B or upgrade compresser wheels to a big 16G or 18G.

 

[BitAddict]

Thanks for the reply! I might just have to hit them up a bit for some stuff. I need to figure out if my turbo is still good though first so i dont waste time and money having to rebuild the thing. hoping to find an easy fix :]

 

[BitAddict]

ok
the ugly: i had two broken studs in the head
the bad: one of them i had to drill and rethread
the good: got the otherone out. could not have been done without the "screw extracting" bits i bought at sears for 11 bucks. i thought when i bought them earlier in the year and they didnt work i had wasted 11 bucks on some cheap crap but it was worth every penny today.
update on turbo: found some more cracks in the hot side turbine housing. since i cant find a place to work on them around here i am going to opt to by the replacement part from forced performance.
ill post again.

 

[GTM]

Originally posted by BitAddict

...
one of them i had to drill and rethread
...
i had wasted 11 bucks on some cheap crap but it was worth every penny today.

update on turbo: found some more cracks in the hot side turbine housing. since i cant find a place to work on them around here i am going to opt to by the replacement part from forced performance.
...

You might get lucky and find a stepped stud so the nut is the same size.

Easy-outs can be tricky and for some tasks they just can't do the job especially if you don't get the hole in the center for it will try to expand the stud/bolt tighter into the threads.
..............

Good luck on the turbo work.

Cheers,
GTM

 

[GTM]

Originally posted by BitAddict

...
one of them i had to drill and rethread
...
i had wasted 11 bucks on some cheap crap but it was worth every penny today.

update on turbo: found some more cracks in the hot side turbine housing. since i cant find a place to work on them around here i am going to opt to by the replacement part from forced performance.
...

You might get lucky and find a stepped stud so the nut is the same size.

Easy-outs can be tricky and for some tasks they just can't do the job especially if you don't get the hole in the center for it will try to expand the stud/bolt tighter into the threads.
..............

Good luck on the turbo work.

Cheers,
GTM

 

[BitAddict]

Well GTM i was staring at the head today and got to thinking... when i rethreaded the hole i could not get i did not make it bigger than the original. i actually drilled pretty close to the size of the bolt that was stuck in and rethreaded that. it seams like it will hold good but im thinking if i take my new smaller bolt and slowly heat it up with a torch while its in there it might expand and help catch whats left of the original bolt???? what do you think? i might then be able to wrench it out slowly????? not sure if this will work or if i should use a steal bolt to do this? Let me know what you think. its so crazy it might just work

 

[babell2]

I decided when I rebuilt my head that I would drill all the holes out and Helicoil them all for improved strenth. If you did manage to bugger up the threads this is still an option.

 

[BitAddict]

yes yes, i thought about this option too but im not going to try and get out anymore bolts just in case one of them snaps as well. its a very good idea though! good news though i did manage to get the other bolt out finally. one side of the threads are a little worn but everything seems to hold tight. the heating up the bolt trick did not work. :[