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Thu Nov 01, 2018 12:57 am

I think most of us with the 1.8t know about this issue.

The 3 bolts that connect the exhaust manifold to the turbo....man, I just can't keep them torqued up.

I believe factory spec is 24 or 26 pounds, I've also tried all the way up to 36#, and they always loosen, especially, it seems, the bolt closest to the exhaust mani.

So I was thinking about this, is there any reason NOT to try studs in there?

I know on mine (AEB motor) the exhaust manifold nuts all would have to be loosened to get the turbo on or off, since the mount hardware underneath the turbo doesn't give enough room with studs in place.

Other than that initial small hassle, is there any reason I'm not aware of that would make this a bad idea?

I was even thinking of double-nutting them. :wink:

On the road, visiting friends and talking about this, one of his kids decided to go outside and check it, and "fix it for me".
"Is that alright?" he asked me.

Sure, go ahead if you want, says me the big dummy.

A few hundred miles further down the road I hear the distintive sound I now know well, and find I have 2 of those bolts broken off inside the turbo. :cry:

Thu Nov 01, 2018 4:39 am

Hey Levi,

These bolts can be a real bitch. I have found that if the car has been driven much with them loose it makes the threaded holes in the turbo wear oblong and then the bolts will never stay tight again.

I can give you a good used turbo or set you up with a brand new BorgeWarner one for wholesale cost along with new fasteners.

Andrew-

Thu Nov 01, 2018 4:59 am

A timely thread for me ...

I currently have my AEB on the stand and starting to 50 degree it, thanks to the musings of kings like Andrew, Mr Gas and others here ( THANKS !! ).

I saw that urotuning has a turbo locking flange to, I think, at least help prevent things from loosening up ...
maybe this would help ?

http://www.urotuning.com/Turbo-Locking-Flange-K03-K04-1-8T-p/uro-k034-tfl.htm

I am not well versed on all the little goodies of the 1.8T yet.

Thu Nov 01, 2018 6:46 am

At some point of time, I would think it's a good idea to replace those bolts because of the heat cycles they live in. That is probably why the bolts broke.

Studs may be ideal if they can fit.

Thu Nov 01, 2018 6:57 am

Loctite Blue, with a nice 24 hour setup time?

SS Washer under the head, bent up to lock bolt in place?

Thu Nov 01, 2018 7:43 am

I don't know anything about this problem, but it seems strange that exhaust bolts are 'loosening'. Is the nut actually turning loose by thermal cycles?

Centerpunch a mark on a hex face of the nut, and another on the bolt thread, a little inboard of the nut. Or somewhere that you can see relative motion. Or is the bolt stretching?

Thu Nov 01, 2018 7:56 am

Something like this if they can supply metric? https://www.stage8.com/

Thu Nov 01, 2018 9:01 am

Sodo, these are bolts that hold the turbo to the exhaust manifold that are the problem here.

VW does offer bolts or studs and nuts for this application, the stud will do a better job holding it in place but I resist using them because it makes thing much much easier to disassemble when there is bolts in this case.
As Butcher has mentioned, these are something that should be replaced each time and a bit of loctite like Abscate has mentioned is a good idea too. That piece offered by Urotuning that Metropoj linked could help, I was not aware this was available.
In Levi's case, it sounds like it has run with them loose a few times and now he's got a couple broken bolts in the turbo ( These can usually be gotten out with a lot of labor, it sounds like a new turbo would be the better solution at this time.

Andrew-

Thu Nov 01, 2018 9:24 am

I don't think even red Loctite is up to the task of securing bolt threads on a turbo flange. I think it needs to be a mechanical grip to work. Nord Lock Washers work pretty well for mechanically locking bolts and nuts. https://www.nord-lock.com/nord-lock/products/washers/

Thu Nov 01, 2018 9:33 am

Having zero exposure to 1.8Ts, which could be better or worse.....

But.... VW did not solve this problem before the 1.8T was removed from it's donor car?
Does the turbo run a lot hotter for longer periods (pushing a brick)?

That splined anti-rotation tab is a really cool device!

Regarding thread locker adhesives on exhaust nuts: How to release Red Loctite®
Removing the red threadlocker involves heating the nut and bolt for a couple of minutes to a temperature of 500°F (250°C)
I suppose having the threadlocker might reduce the corrosion? But it seems more like a 'thread lubricant' than 'locking compound' at exhaust temps (towards 1000F?)

Thu Nov 01, 2018 9:54 am

To remove a fixture that was been installed with loctite, you should use heat. That said, installing loctite on an exhaust fastener is not going to help solve of the fastener coming loose.

Friction holds the bolt in place, the only thing I can think if is that the threads are worn out. Locking tabs, serrated washers [not the standard split lock washers], or safety wire may help with exhaust fasteners.

Thu Nov 01, 2018 9:55 am

What is the material of the fastener you are using? I've seen stainless bolts in other turbo applications.

In the short term maybe drill the heads of the bolts, install and torque to spec, and then use stainless steel safety wire to secure them in pairs..

Dave

Thu Nov 01, 2018 9:56 am

If the cut threads in the housing are good and the bolt isn't stretching but is indeed turning........ I'd use the old wire the bolt head trick.

Dave

Thu Nov 01, 2018 10:13 am

Sodo wrote:

But.... VW did not solve this problem before the 1.8T was removed from it's donor car?
(pushing a brick)?

This was my first thought. A quick search on the 'net shows incidents of this on 1.8T engines in the stock application. But.... I don't know exactly which 1.8T engines. One thread mentioned vibration as a factor. Does VW reccomend a special bolt here? (uses specific metal content for higher heat application?)

Neil.

Thu Nov 01, 2018 11:08 am

Once an iternal thread has been “worn loose”; vibration and perhaps heat cycling can “walk” it within the slop. And it will walk in one direction ——> “loose”. Needs a mechanical lock or fresh new tight threads.

Especially a very short bolt that has no “stretch” to retain the preload tension over each vibration cycle.

Thu Nov 01, 2018 11:17 am

This isn't a 1.8T, but the same thing could be done with sockets on one, including an AEB.

Thu Nov 01, 2018 11:44 am

Christopher Schimke wrote: This isn't a 1.8T, but the same thing could be done with sockets on one, including an AEB.

Ahhh the old 'safety wrench' fastening technique..... :lol:

Thu Nov 01, 2018 12:32 pm

the problem people run into when they think "OK MORE TORQUE THEN" is that when the turbo and header are red hot, everything stretches,, and if already over torqued, won't rebound to the right clamping force

From the other thread on the topic
https://www.thesamba.com/vw/forum/viewtopic.php?t=703065&highlight=inconel

danfromsyr wrote: OEM turbo bolts are a special grade of Stainless steel.

both my friend and I have a 1.8T swap and played hell with the turbo to header gasket blowing out.
my brother hasn't had an issue (yet anyways)..

I will 2nd that PROPER TORQUE.. not too much not too little..
I'm a shadetree that seldom uses a torque wrench on non-critical parts.. I tighten by experience to what a fastener that size should go..

in this case the torque is low for those bolts as they are expected to get really hot (red) and cool multiple times. and a too tight fastener will stretch past it's limits.

in my case I went with custom made INCONEL studs and STAGE8 RACING locking nuts. I had to commission the studs via ALIBABBA just under $300 for a few sets. they won't do just the 3pcs you need.

edit I did find this .AU company listing inconel studs.
I do not recall what size&length are required at the moment.

and I do not know if these people will ship to the US.
https://gcg.com.au/petrol-performance/performance-3/studs-and-nuts?limitstart=0

Thu Nov 01, 2018 4:47 pm

xoo00oox wrote: Sodo, these are bolts that hold the turbo to the exhaust manifold that are the problem here.

VW does offer bolts or studs and nuts for this application, the stud will do a better job holding it in place but I resist using them because it makes thing much much easier to disassemble when there is bolts in this case.
As Butcher has mentioned, these are something that should be replaced each time and a bit of loctite like Abscate has mentioned is a good idea too. That piece offered by Urotuning that Metropoj linked could help, I was not aware this was available.
In Levi's case, it sounds like it has run with them loose a few times and now he's got a couple broken bolts in the turbo ( These can usually be gotten out with a lot of labor, it sounds like a new turbo would be the better solution at this time.

Andrew-

Hey that's my turbo right there!
Ha ha but with 2 broken bolts!

Hey Andrew what's up?
Very awesome of you as usual, your offers, Thank You, I may take you up on that, but first I see an opportunity to try different things.

AND I'm just the right amount of twisted loony that I kinda enjoy the challenge of seeing what's going to happen.

I'm in an idyllic spot, no one around, no hurry to be anywhere, and lots of tools and parts so I'm good.

I agree, so far drilling this out is a lot of labor.
I've got taps and various helicoils and studs and even 3 new turbo bolts from a vw stealership.
The bolts have their own vw part number, so they're not just standard bolts.

But, thanks to your heads-up, I'm not going to try those.
I hadn't thought about the effect on the threads in the turbo caused by a loose bolt.....

The thing is this turbo shaft is still so TIGHT, be a shame to give up on it.

I think I'll try next size up with studs.
Let's see what happens.

Thu Nov 01, 2018 4:51 pm

Thanks everyone for the ideas and suggestions.
That locking flange from eurotuning looks interesting, as well as the stage 8.