Head Games
On the way back from Golden West, my traveling companions noted that the Saab was producing oily smoke on hard engine braking, such as when exiting the freeway. The initial diagnosis was possible leaky valve seals. During the trip home, the car turned over 240K miles on the odometer; I have no idea whether the head is original or not.
On the advice from folks at the SaabCentral forum, I decided to try a treatment of SeaFoam to clean deposits from the valves. I went with the technique described in detail at the Turbobricks forum with the help of a neighbor and the amount of smoke produced was astonishing. At one point I was waiting for an '80s metal band to come out of the expanding cloud and tear into an opening number -- it was that good. The neighbor across the street came out to ask if he needed to call 911. Smoke came from every crevice in the exhaust system, including the connections between the turbo and header. Truly spectacular. Anyway, for all that smoky drama, I didn't really see a difference, and can still get the car to smoke under high vacuum.
Another opinion is that the oil ring seals are worn. There's apparently no way to tell for sure without going into the block -- a project I don't want to begin this close to the Alcan start.
Two days ago I decided to check engine compression, and pulled all the plugs and used my new compression tester. The numbers were decent: 150, 140, 140 and 165. I put things back together, including the plate that covers the plugs where they're installed between the two camshafts. Planning on checking the engine timing next, I attempted to start the car and with a loud KABOOM and crash, had to quickly shut 'er down.
The cover plate was bent, and upon removal, I found the #2 plug the cause, being blown out of it's position in the head. Tried to reinstall but the threads in the cylinder head were stripped and the plug refused to be tightened. Oh crap!
Reported back to the SaabCentral forum; and one of the members suggested a Time-sert repair kit. Unfortunately I couldn't quickly locate a nearby supplier and went to the parts store chain whose name rhymes with Sucks instead. Got their no-name Heli-Coil knock off which was all they had available. Hans came over to cheerlead the attempt, and after demonstrating again how to launch a spark plug across the garage, I decided to go ahead with the repair kit. We modified the kit's tap in order to be able to fully thread it into the head, and then spent a lot more than ten minutes of effort tapping the hole and installing the insert, resulting in a broken insert that left the majority of threads in place.
So now the car is back to running normally, at least at idle. Now I need to drive the heck out of it over the next few days to see if the repair will hold. And start shopping for a replacement head to rebuild in the fall.
Oh -- checked the timing -- it's where it needs to be. Probably need to tweak the wastegate a little to get the boost increased a tad. Will do that when I spend a day to go over everything for a last minute pre-Alcan check.
It's very hot in Seattle. A real sweat-fest working in an uninsulated garage. At least it's in the shade. The only thing worse than the heat is all the people whining about it!
On the advice from folks at the SaabCentral forum, I decided to try a treatment of SeaFoam to clean deposits from the valves. I went with the technique described in detail at the Turbobricks forum with the help of a neighbor and the amount of smoke produced was astonishing. At one point I was waiting for an '80s metal band to come out of the expanding cloud and tear into an opening number -- it was that good. The neighbor across the street came out to ask if he needed to call 911. Smoke came from every crevice in the exhaust system, including the connections between the turbo and header. Truly spectacular. Anyway, for all that smoky drama, I didn't really see a difference, and can still get the car to smoke under high vacuum.
Another opinion is that the oil ring seals are worn. There's apparently no way to tell for sure without going into the block -- a project I don't want to begin this close to the Alcan start.
Two days ago I decided to check engine compression, and pulled all the plugs and used my new compression tester. The numbers were decent: 150, 140, 140 and 165. I put things back together, including the plate that covers the plugs where they're installed between the two camshafts. Planning on checking the engine timing next, I attempted to start the car and with a loud KABOOM and crash, had to quickly shut 'er down.
The cover plate was bent, and upon removal, I found the #2 plug the cause, being blown out of it's position in the head. Tried to reinstall but the threads in the cylinder head were stripped and the plug refused to be tightened. Oh crap!
Reported back to the SaabCentral forum; and one of the members suggested a Time-sert repair kit. Unfortunately I couldn't quickly locate a nearby supplier and went to the parts store chain whose name rhymes with Sucks instead. Got their no-name Heli-Coil knock off which was all they had available. Hans came over to cheerlead the attempt, and after demonstrating again how to launch a spark plug across the garage, I decided to go ahead with the repair kit. We modified the kit's tap in order to be able to fully thread it into the head, and then spent a lot more than ten minutes of effort tapping the hole and installing the insert, resulting in a broken insert that left the majority of threads in place.
So now the car is back to running normally, at least at idle. Now I need to drive the heck out of it over the next few days to see if the repair will hold. And start shopping for a replacement head to rebuild in the fall.
Oh -- checked the timing -- it's where it needs to be. Probably need to tweak the wastegate a little to get the boost increased a tad. Will do that when I spend a day to go over everything for a last minute pre-Alcan check.
It's very hot in Seattle. A real sweat-fest working in an uninsulated garage. At least it's in the shade. The only thing worse than the heat is all the people whining about it!
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