A non-Opel story

[wklopf]

This story does not involve an Opel, but I figure that a bunch of mechanically-inclined people might find it of interest. The car which I routinely drive is a 1996 Acura Integra LS with five-speed. I bought it new and it now has 270,515 miles on it. The LS has a DOHC engine with a timing belt which is to be changed every 90,000 miles. The first time the belt had to be changed, I took it to the dealer where I had bought it. After paying the bill of some $1300, I decided that I was never going to do that again! So, I have done all of the maintenance work on the car since. Repairs have been few, and the engine had never been opened up. The car has run well and produced excellent fuel economy, but keep in mind that I am FAR older than the typical Integra driver. Anyway, as I was getting ready to replace the valve cover after replacing the timing belt this time, I happened to notice a piece laying loose on top of the cylinder head. I retrieved it and knew immediately that it was a rocker arm! It was from one of the intake valves on #4 cylinder. I could not see how it could have come out, but I thought that if I backed off the adjustment screw and depressed the valve spring a bit, perhaps I could slip it back into place. That is when I learned that that intake valve would not budge! I finally tapped on it with a punch and hammer and it did go down a bit: and stayed!

At this point I didn't know if I had a bent valve stem or what might be wrong, so I started removing the head. I examined all of the parts which were involved for this valve and could find no trace of damage of any sort! I had to tap the valve stem all of the way out of the guide. The valve port for that valve had a large amount of carbon deposit on the side away from the operating valve. Since the injector is located right between the two intake valves some fuel was being injected against this closed valve. probably contributing to the carbon deposits. Other than a deposit on the stem of the stuck valve, I could find nothing wrong with the valve. I checked the stem diameter with a micrometer and found it to be within specs. I got a cylinder bore gauge and checked the cylinders for wear and also found these to be within specs. So, I am just reassembling the engine, replacing only gaskets.

I can see no way that the rocker arm could have come out of a running engine without showing some signs of damage. Since there is no damage and this is the first time the engine has been opened up, is it possible that the engine could have come out of the factory with one rocker arm not installed? If that is the case, then by noticing the rocker arm this time, I just made a whole lot of work for myself since I had not had any problem with the way it was running. I called the service department of the dealer as well as the Acura service number. I'm not sure that the person I talked to at Acura had any idea of what I was talking about. I have put part of this on the TeamIntegra site. If anyone has any thoughts, I'd like to hear them. Bill

[AZManta]

I was a heavy-line mechanic for some GM dealers in the late '70s and through the '80s.
You would not believe what I have seen. Porous engine blocks, missing main bearing, mis-machined transmission cases. The Japanese have the illusion of being perfect but they are human just like us...