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You may recall that Randy H. was asking us last week about his # 3 & 4 cylinders which weren't firing at idle. Well, he did as much as he could working at home, and then drove his '71 square up here so we could look at it together. The FI checked out just fine. The ignition was also okay. But # 3 & 4 cylinders had zero compression. I checked the valve adjustment and found that # 3 & 4 exhaust valves were tight. # 3 adjusted okay (I probably had to back it out 1 turn), but # 4 just adjusted out and out, until the valve spring was hitting the rocker rather than the valve stem. Randy drove it home, and reported that # 4 was actually contributing something (I had originally disconnected the # 4 injector, but he put it back on the trip home.) I'm surprised at this, because it just seemed that there was no way for this cylinder to be building up any pressure. At any rate, here's the question: Do valve stems sometimes actually stretch before they break? I've seen valve seats which have sunk into the head, which would mean a new head is in the works, but I've never seen a stretched valve. OTOH, the fact that VW gives the total valve length and tells you to check it, makes me wonder if there's actually something to this. There's also a warning here for those of you who might be new to air cooled VWs. The valves in these engine require regular checking and adjustment. Just because you've never had to do this in anything else you owned doesn't mean that you can get away with that here. While I was under this car, I adjusted all the valves. All of them needed adjustment, but only the exhaust valves on the left side had gone completely tight. Randy admits that he should have checked these, but had never gotten around to learning the process. I agree that it's a bit intimidating the first few times, but it's really not rocket science; anyone can do it, and with minimal tools. -- ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~