The title says it all. For the benefit of the search engines, I should mention that this should apply to most 1.0L 3-cyl Geo Metro, Suzuki Swift, Pontiac Firefly and Chevrolet Sprints made around 1991 (89-91).
Basically I can sum it up by saying this. We had an engine that started to perform badly and over the course of 2 weeks really took a hit to the point where it didn’t even want to go over 90 km/h. It seemed like the timing was retarded, and would sputter, cough, and had terrible performance at low rpm’s. I’ve read through the teamswift.net forums often enough to know that these engines are prone to burnt exhaust valves, so we figured that was probably the cause. A compression check verified this.
We pulled off the head and took a look. Sure enough, there was a flat section where the valve wasn’t sealing any longer. Seeing’s how we had a parts car and weren’t looking to feed any more money into this one, we pulled the head from the parts car which fortunately still had 1 non-burnt valve left on it (you can guess why it became the parts car). We grabbed the good valve from the parts car and swapped it with the bad one from the current one. Since we already had the head out, we took the opportunity to lap all the valves which was probably a good thing, since most weren’t in the greatest of shape. Once it was all said and done, we oiled everything up and put the head back together.
Before bringing the head back to the car, we thought it might be a good idea to turn over the camshaft a few times just to make sure the valves were all opening and closing properly. It’s a good thing we did, because the exhaust valve we replaced wasn’t closing all the way. continue reading…