AAARGH!!!! my new head has damaged t/b tensioner threads

[texcl]

I got her all together, went to put the t/b tensioner stud in, I had noticed the threads didn't look right, screwed in the stud and noticed alot more tension than on my original head, backed her out and noticed the threads on the stud were now distorted, I had anouther stud so I tried it same thing, I get it mostly in and when the last 3 threads are left it binds up and distorts the threads, now what, should I pull the head and waste $60 in gaskets, send it back and probably pay $100 in shipping, or keep trying to seat it all the way. Did 1.5's have other that 10mm tensioner studs or were they tapered? I'm so upset I'm ready to quit.

[Gromit]

Perhaps you have the wrong stud- with inch threads? or-
Use a small drill bit to dig out whatever is impacted at the bottom of the hole, and chase the threads with a metric tap. Even if you have to drill and tap for an insert, there is no need to remove the head, can be done with hand tools.

[texcl]

Ok, I ran the stud through a 10x1.5 die to fix the threads then went and ran a 10x1.5 tap through the stud hole , the hole was alot deeper than I thought which is good, that many more threads to engage. So I inserted the stud and walla she turned in, still pretty tight but she smoothly seated. the threads had been sand blasted and I'm not sure if that makes them tighter or what, but she's in there tight now, I hate to remove it but I might tomorrow so I can clean the hole with brake cleaner, blow it out and put some loctite in there for good measure.

[82vdub]

Just so you know, a tap and die will remove thread material from the threads, since it's meant to cut new threads. A cleaning tap is made much different and will only remove junk material from distorted threads. I'm not sure if you should try to run it as it is, or remove the stud and tap for a larger stud (but that could lead to issues with the tensioner). If this component fails, it's an interferrence engine and severe damage will be the end result.

[texcl]

Yeah I worry about that too, if worse comes to worse I might just send it back to the head shop that did the work and tell them to install it properly. I don't know, this is all very frustrating, I just want to get the sob on the road at this point.

[texcl]

well, I cranked down the tensioner to see if the stud would hold that kind of torque now, it held enough torque to crush the face of the tensioner which is made of a thick stamped steel. The tensioner face yeilds at 32lbs according to my wrench, so I dont know if I should test my luck or not, it seems it will hold, the hole is not stripped and the stud is tight and not wobbly through the whole screw down cycle, I even tested the tensioner on another head that I know has good threads and it yeilded at the same torque, so I know it is the tensioner yielding, (not to mention the big washer impression). What do yall think, my other option is to send the head back and have them fix it.

[82vdub]

I sounds like it should probably work out and hold tension.

[texcl]

OK, I have decided to take it all apart and helicoil it. So I decidedto see how much torque I could put on it before the tensioner stopped yielding, I got it up to 33lbs (the target torque) with no movement. So I don't know I put so much time and money in this car and I love the car, I guess I should still helicoil her. What's another week after a month of work, a new head, starter,new water pump, new injectors and all new filters.

[Gromit]

That one stud could ruin an engine. My AAZ uses the TDI-style spring-loaded tensioner; that one is supposed to be tightened to only 15 ft-#, rather than 33 ft-#.

15 ft-# isn't much, makes me worry. My tensioner was broken when I got the motor, crushed under the nut from being tightened too much. I figure the best thing for it is to use jam-nuts; torque the first one to 15, then hold it still and put the next one on good and tight. And have the stud glued in with Permatex.

But then I have a problem few of you have. My engine (when it is finally fixed) goes into a Kubvan, The timing belt is an inch from a wall, the tensioner can't be removed without disconnecting the mounts and lifting the motor up. when the old 1.6 was in there, I'd replaced the stud with a bolt, that allowed the tensioner's removal. I tightened that bolt down good. I can't do that with this spring-loaded tensioner.

Any ideas?

[Fatmobile]

I don't think I'd helicoil it, doesn't sound like there is anything wrong, didn't go in wobbly, felt tight, plenty of threads.

It's a stud, it should be fine, not like you are grinding the threads out as you turn it.
Torque it to 40 and see what happens, if it doesn't pull out, put it back to 33 and leave it.