1979-1993 & 94 Conv [Subscribe to Daily Digest] |
More info and details.
The head did go to a machine shop... the ONLY shop in our area, so probably not very SAAB oriented. However, when reading the Townsend tech article and the Bentley manual, you really can't remove very much material from a SAAB head before messing things up (like too high compression). So if the head didn't need cutting, it wasn't to be done.
The head was checked for being warped. It was flat. No milling was required. The shop cleaned the head, pressure checked it for leaks, checked and lapped the valves and reinstalled new valve seals. The gasket mating surface was cleaned up to a clean metal surface. No irregularities or major pitting was on the head, just the minor porosity found in an aluminum casting.
The block side was cleaned by me using a scotch brite Roloc medium grit surface conditioning disk in an electric drill. Both surfaces were cleaned with acetone to remove any traces of oil. No gasket material remained from the old gasket. It was clean metal to metal contact.
Here are some of my theories that I think may have gone wrong.
When installing the head there are small guide pins that help align the head. How critical are they? There were three when I pulled the head. Two stuck in the block and one was removed from the head by the machine shop. When installing the head, my fellow SAAB nut friend and I couldn't figure out where the extra guide pin was to be placed. It didn't fit in any of the remaining holes, so we carefully lifted the head onto the block, thinking that the two remaining guide pins in addition to the bolts, would be sufficient to align the head.
After lifting the head into place (which was much easier with my SAAB friend helping) The head rested on the block but didn't fully seat over the guide pins. We gradually applied torque to the bolts using the alternating torque tightening sequence. The head drew down to the block and we continued with the torqueing procedure.
The gasket was an Elring. We also used the NEW STYLE bolts. There was lots of controversy regarding using new versus old bolts in variuos SAABnet posts. Last year Anders posted a comment to my question regarding the bolts. (yes, it took me a year to get this job done!). In his post he seemed to prefer using the old bolts if they were clean and not rusted.
Apparently the old bolts were torqued to a higher value than the new ones (80nm vs. 60 nm). Coulod the leak be from the "undertorque" condition mandated by the new style bolts?
Another issue is that the instructions for the Elring head gasket installation suggested using oil on the washer between the bolt and the TOP of the washer. I inadvertantly applies oil to the entire top of the bolt, so I'm sure some got between the washer and the head.
I'm sure that I will do the job again... so I'd appreciate any insight into what we should look for after pulling the head off again.
sorry for the long post.
Joe C.
posted by 72.9.24...
, Wed, 3 Jan 2007 20:43:36
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
