[urq] Cylinder head retorque

[Peter Golledge]

AFAIK all I5 Audi head bolts are TTY "Torque to Yield" AKA "stretch" bolts.  I'd not expect them to have the same
torque + turn after heat cycling but I don't know if that would explain the 120 Deg difference?


On 10/14/2010 6:42 PM, Louis-Alain Richard wrote:
> Hi everyone,
>
>
>
> A little wrap-up from two years ago. I exploded the engine (stock) in my 250
> 000 km urQuattro in January 2008. I replaced it with a lightly rebuilt stock
> WX (block and piston's grooves cleaned, new rings and bearings, head checked
> and cleaned, new gaskets) in June 2008. The car saw only a few ice racing
> sessions after that, gentle ice lapping would be a better description, and
> maybe 5000 km of street duty. In January 2010, I had to replace the heater
> core, which I did. After that, I noticed there was some "bubbling" noises
> coming from the heater core. I thought it was air trapped in there, and it
> would go away after a few km. I ice-lapped the car 2 more times in 2010, and
> used very little afterwards. I did notice however that the car smoked on
> start-up, thick white smoke that disappeared after a while.
>
>
>
> Recently, like last month, the smoke was permanent. Time for a head gasket
> replacement, or maybe even a head replacement since these WX are prone to
> cracks between the valves.
>
>
>
> Today, we removed the cam cover, just to discover that every single head
> bolt was under torqued. As an example, I adjusted my (new) torque wrench to
> 45 ft-lb, and was able to add 30 to 60 degrees to each bolt to reach that
> setting after I "cracked" loose the stiction.  The specs are 29 ft-lbs, then
> 45, then add 180 degrees. We followed that sequence in 2008, with new head
> bolts and a good Snap-on clicker torque wrench.
>
>
>
> Now, tell me, what went wrong ?
>
> We used a (made in Germany) Elring gasket set, a lot of new stuff, we took
> our time, didn't drink too many beers, it was nice outside, the moon was in
> Capricorn, etc.