When I asked my mechanic about a couple things regarding service he did on my car, a few things didn't seem right. Anyone with experience in the field know whether these explanations hold water, or whether he's full of "Shaving Cream"?
- Timing belt. Both this car and my previous one, whenever I got the timing belt done the mechanic would put a sticker on the timing cover showing the date and mileage at which the replacement was done. This was the first timing belt replacement that he did for me, and he didn't do the sticker. He said that there wasn't one included with the timing belt kit - it would seem to me that it would be a logical thing to have in the kit, since it would be natural to want to have it show on the car when the belt was last done. Anyone except a VERY busy shop wouldn't do enough timing belts to be worth printing up their own stickers. Is it normal for a sticker to be included in the kit?
- Welding. He welded in a generic flex pipe (OEM flex pipe is expensive, and includes a couple of major components), but didn't weld all around (couldn't get the MIG head onto the top without dropping the exhaust). I asked why he hadn't gas welded it (tip is smaller, and has a wider choice of angles to work from), and he said that gas welding was weaker and more susceptible to cracking, due to the lower temperature. My understanding is that for a given type of metal, there is a limited range of temperatures involved for welding (too low and the base metal doesn't melt to fuse with the filler, too high and you'll wreck the base metal) regardless of the method used, and that welding methods where the heat source and filler are separate (gas, TIG) give more control than a combined "heat and fill" (stick, MIG). Is gas welding suitable for exhaust work?
- Timing belt. Both this car and my previous one, whenever I got the timing belt done the mechanic would put a sticker on the timing cover showing the date and mileage at which the replacement was done. This was the first timing belt replacement that he did for me, and he didn't do the sticker. He said that there wasn't one included with the timing belt kit - it would seem to me that it would be a logical thing to have in the kit, since it would be natural to want to have it show on the car when the belt was last done. Anyone except a VERY busy shop wouldn't do enough timing belts to be worth printing up their own stickers. Is it normal for a sticker to be included in the kit?
- Welding. He welded in a generic flex pipe (OEM flex pipe is expensive, and includes a couple of major components), but didn't weld all around (couldn't get the MIG head onto the top without dropping the exhaust). I asked why he hadn't gas welded it (tip is smaller, and has a wider choice of angles to work from), and he said that gas welding was weaker and more susceptible to cracking, due to the lower temperature. My understanding is that for a given type of metal, there is a limited range of temperatures involved for welding (too low and the base metal doesn't melt to fuse with the filler, too high and you'll wreck the base metal) regardless of the method used, and that welding methods where the heat source and filler are separate (gas, TIG) give more control than a combined "heat and fill" (stick, MIG). Is gas welding suitable for exhaust work?


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