In Parts 1-5, we covered my search for, and acquisition of a 1969 International harvester Scout 800A, getting it running, getting it stopping and the joys of carburetor rebuilding. Today, we will get into fixing a slightly more complex issue.
I had driven the Scout around a good bit, but always short trips, and always within a few miles of home, just in case something went wrong. One fine summer evening, a friend of mine called to see if I could lend him a hand changing the intake manifold gasket on a truck he was getting ready to sell. I was happy to help, as I was trying to gain as much wrenching experience as i could get, however beyond being an extra set of hands, I'm not sure what made him think I'd be useful for. Since he only lives a few miles down the road, he was within my 'Scout driving comfort zone'. I hopped in, and headed over. After a few hours, we had the gasket replaced on his truck, and it was time to head home. After arriving home, my buddy called and informed me that the Scout didn't sound like it was running right, particularly at idle. He said it sounded like it was misfiring. Knowing that all the ignition parts were new, I dismissed his comment.
Fast forward a couple of weeks, and it was finally time for me to take the Scout to my first Cars & Coffee. I had an awesome time, talking to great people and seeing some amazing cars. I must admit, it was a little odd seeing my rusty old blue Smurf turd tucked neatly in, between a 458 Italia and a 1927 Rolls Royce Phantom. Anyway, as things were wrapping up, I started the Scout and let it idle while I was talking to the owner of the Rolls. He casually asked if I had a plan of attack for my stuck valve. He took me to the back of the Scout, produced a dollar bill, and held it against the end of the exhaust pipe. The bill blew around in the exhaust stream, but, was occasionally sucked back against the exhaust tip. He explained that this was because one of my exhaust valves was sticking open, and when the cylinder was moving down on the intake stroke, it was pulling air in through both the intake and exhaust valves. I thanked the older fellow and headed home to do some research.
If you look around on the web, there are many, many suggested methods for magically unsticking a valve. As usual, I decided to start with the easiest and cheapest methods first. At the top of that list, was running a quart of ATF in the crank case. This is supposed to gently remove 'crud' from the system, due to the high levels of detergents in ATF compared to regular motor oil. I tried that for a few weeks, with no luck. Next up, was Seafoam. I added a half a can to the gas tank and the other half to the crank case. I ran that way for a week with no improvement (though I will say, the oil that came out after both of those treatments was pretty nasty, so they probably did clean things up a bit). Noticing no improvement at all, it was time to step things up. The next suggestion, was to remove the valve cover, directly lubricate the offending valve stem, and try tapping it with a brass hammer or other soft mallet to get it moving up and down smoothly. I knew that there were any number of mechanical issues I might encounter once the valve cover was off. The valve could be bent or burned, the rocker arm may have some problem, the issue could even extend to the cam lobes. I was hoping though, that with less than 50,000 miles on the engine, it wouldn't be anything catastrophic.
Luckily, one of the local parts places had a valve cover gasket in stock, so with tools in hand, new gasket in the box, the sun on my back and (most importantly) my wife and kids out of town, I set to work. I was relieved to see that the rocker assembly, springs, retainers and all the other hardware looked just like the pictures I had seen online. A quick visual inspection revealed that the rocker arms all looked fine, none of the springs were broken, and everything looked to be in good shape. With the coil disconnected, I contorted myself into a position to crank over the engine so I could watch the valves and rockers, and hopefully determine which one was sticking. As the rockers moved up and down, I heard a clear ticking noise. Investigating more closely, I saw that one of the pushrods was bent. I panicked. It's worth mentioning at this point that the extent of my vehicular wrenching was changing oil and brake pads, and once replacing an alternator in a mall parking lot where my car had left me stranded. Pushrods, and any internal engine parts, were a whole other thing as far as I was concerned. I had no idea what was involved in replacing a pushrod, what materials I needed, how to go about it or where to get parts. My fantastic little summer truck, that I had been lusting after all these year, might have a terminal injury. Something that was beyond my ability to cope with. I might have to suck it up and sell it off to someone with more skill than I had. At this point, I seriously considered replacing the valve cover and either ignoring the problem, or listing the Scout on Craigs List. After drowning my sorrow in a few beers, and then sleeping on it, I came to the conclusion that I had nothing to loose. I could try to fix it, and either I would succeed, or be forced to give up and sell, in which case I wouldn't really be any worse of than where I already was.
Back to the internet! After reading a bunch of posts, and one particularly well done treatise on the International Harvester valve train, I thought this was something I might be able to handle after all. After a few calls to local parts places, I found one that could have me a new pushrod and lifter (just to be on the safe side) the next day. I went to pick up the parts along with the rest of the supplies I was told I would need. Things like thread sealer, assembly lube (that just sounds dirty), several cans of brake cleaner, a lifter removal tool, and a torque wrench. As a quick aside, I initially recoiled at the cost of a decent torque wrench, but let me tell you, if you plan on working on cars at all, and care even a little about doing it right, suck it up and get yourself a good torque wrench. You'll thank me later, I promise. Following the write-ups I had seen online, I removed the rocker assembly, disassembled it and tossed it all in a bucket of parts cleaner. These particular rockers have some very small passages for lubricating the spot where the rocker and pushrod intersect, and it was pointed out that if I had the assembly out anyway, I might as well make sure they were good and clean. With the rocker assembly out of the way, I extracted the bent pushrod and it's associated lifter.
I followed the instructions for pumping up the new lifter, and when I went to place it in it's hole, I promptly dropped it into the abyss of the valley (or half valley, as this is an I4, not a V8). Thankfully I already had a magnetic pickup tool with an LED on the end of it, so after some fishing around, I was able to retrieve the lifter and get it in it's hole. In this particular IH engine, oil comes up through one of the rocker stands, into the tube the rockers are mounted on, and then flows out of various holes the lubricate the entire area. Since a good seal between the rocker stands and the head were required, a Scotch Brite pad and some brake cleaner were used to clean the mating surfaces. The new pushrod was installed. Can you pick out the shiny new pushrod?
With everything out of the way, I lubed up the valve that corresponded to the bent pushrod, and tapped it a few times to make sure it was moving freely. It was, so assembly lube was applied to the pushrod sockets and valve stem pads. The rocker assembly was cleaned and put back together (thanks in large part to a LOT of pictures I had taken before I took it apart). Thread sealant was applied o the rocker stand bolts, since several of them pass through into internal passages in the head. The rocker assembly was loosely bolted down, and after some trial and error, I was sure all the pushrod ends were in their lifters, and the balls on the ends of the rocker arms were in the socket ends of the pushrods. Everything was torqued down to spec. Resuming my contorted position, I cranked over the engine, and was rewarded with the smooth, quiet up and down motion of the rocker arms and valves.
I re-torqued all the bolts, put on the new valve cover gasket (after a LOT of cleaning of both mating surfaces. They were both covered in old gasket and baked on oil) and tightened down the valve cover (again, thank you torque wrench). I reconnected the coil, pumped the gas and turned the key. I was greeted with a smooth, even idle, and the quiet purring of the engine. Success! I had conquered yet another Scout demon. I had been into the belly of the beast and emerged victorious! Ok, well, really, I had done a fairly simple mechanical repair, but to me, it was akin to having just performed successful hear surgery for the first time.
For the first time, I was really feeling like fixing up this Scout into something I could be proud of might be something I could actually accomplish. Not only that, but i was also feeling more and more like the Scout was a vehicle I could rely on. One I could drive more than a few miles from home without worrying about if something was going to break and leave me stranded. As much as I had been fond of the Scout before, just because it looked cool to me, I now felt connected to it. We had a bond between us, and I knew I owed it to the rusty, trusty little Scout to see my restoration plans through to the end, even if it might take years (which it probably will).