Pulled this off the engine and transmission page: Hi,first time here: Sorry if this is common knowledge, but I could use some advice. My old stock 49 chev 1 ton has always run great when I've needed it too. I only use it rarely, for hauling firewood a few times a year.I have owned it for 25 years, or more.It never miss's a beat. I started it up the other day,and it knocked like never B4, then wouldn't start again. Long story short, I removed the valve cover, and push rod cover, and found 3 bent push rods, and 3 stuck valves. I freed up the valves with WD40,replaced the bent rods,and put it back together.It ran great for a good 1/2 hour. Very Happy. Next day,I tried to start it again and the same thing happened, only this time it was 5 bent push rods,5 intake valves where siezed up. Very Unhappy. The exhaust is rusted out, and I have been using unleaded gas forever. Any Ideas..? Thanks, Response: Sounds to me like you have no oil to the top end of the engine. Gallery in the head might be clogged. While you had the rocker cover off, did you notice if there was oil coming out of the weep holes in the rockers when the engine was running? If you replaced the push rods and fired it up, even without oil, it would run for a while before the valves seized and then bent the push rods. These engines were designed to run with little oil to the top of the head, but not to run with no oil. So, freeing up the stuck valves by lubricating them would allow the engine to run for a while like you said and then seize up again. You should pull the little NPT plug on the push rod cover side of the engine head about midway down the length of the head. This is the oil gallery to the head. check to see if it is plugged up or full of gunk or worse...dry. If you only run the truck a couple of times a year, sediment could have worked in and just crudded up the whole works. Common fix as I understand it is to plumb an oil line from the fitting where the gauge runs into the block on the manifold side of the engine around the back of the engine and into the gallery plug hole on the head on the rocker cover side of the engine. This woud definately give you plenty of oil to the top of the engine and ensure that the valves are properly lubricated. BTW, I personally would not use WD40 to free up the stuck valves. I like Marvel Mystery Oil for that task. If you get lubrication after you plumb the new oil line, switch to a thin full synthetic oil like 5W-20 or 5W-30 for a while. Synthetic oil is very slippery and very detergent and will clean out the galleries in no time flat. How's the oil pressure at the gauge BTW? Replace the bent rods, fre up the stuck valves with Marvel Mystery Oil, pour fresh oil over the entire valve train and run it again, making sure to check the weep holes on the rockers for oil seeping out when running. If no oil comes out of the rockers within a VERY short time, you have a plugged gallery and no oil to top of engine. If this is the case, plumb the new line as mentioned, pour more fresh oil over the entire valve train, fire it up again and check the rocker weep holes for oil coming out of them when running. Just my two cents as a hobby mechanic. I am sure others (like Nate) will tell me I'm wrong, but it makes sense to me. Just posted this and saw Chris's reply after posting. He could be right about the varnish because he is right on with the advise as usual, but check the rockers for lubrication just the same. First, truck is out in the bush and you use what you have on hand, hence the WD40 to free up the stuck valves. Works good on small aircraft motors when the same thing happens but they are using leaded fuel. Next is the oil supply. This is a line that runs up to the head in behind the pushrod panel on the right side of the motor. Oil pressure is at specs. Oil tube runs to the rocker assy but has a small pipe that pops out the opposite side of the oil line connection and is wide open, dumping oil back down through the head to the lifter section. Thought this was odd as the bulk of the oil is not used to lube the rockers assy's. Is that suppose to be there ?? Creeker1 Mech
Are you certain it's a 216 ? usualy only 235's have that excess oil dump tube but as long as there's oil coming out the rocker's weep holes on top , it's normal for the rest of the oil to pour out that tube facing down... WD=40 is only solvent and isn't going to do the job . I thought I'd replied to this one allready , no ? . Jump in guys .
Sticky guides Ya Nate I think we have been here before. I've had this stuck valve bent push rods, pulled rocker stud thing happen to me and the cause in my case was bad gas. I probly go to the extreme, but I pull the head and disasemble the valves, work the varnish out of the guides with spray carb cleaner. It takes alittle work to get all the varnish out of the guides, so the valves are free again. All this is a waist of time if you dont drain all the bad gas out and put fresh in. If you dont use your truck very much you should consider putting some Stybil in your tank to help preserve the fuel. Chris
That Sux ...The poor quality fuel we get these days . I bought a Russian Moto in Louisiana and a year later decided to use the fuel tank off of it , as I was preparing to drain and discard the (presumed stale) fuel , my buddy said ' if you're going to dump that fuel , lemme have it ! ' ~ I was astounded but sure enough , when I drained it , it was real gasoline ! bluish pink and eveything ! we don't get that here in California , we get corn Foo-Foo tree hugger crap . it's YELLOW for cripe's sake . I still say , squirt some marvel Oil or ATF on those sticky valves and run it for a while , I've unstuck lots and lots of them , never bent a valve nor pushrod yet.... When I take my truck out , I rarely run it less than 2 ~ 3 hours so it gets used on a fairly regular basis . I'd drive it more but $3.00 gallons and maybe 10 MPG makes it tough for this working man . If you take the head off , seriously consider having silicon bronze valve guides fitted along with stainless steel valves , that'll be the very last valve job you ever do on it .
Guys, you're talking my lingo now! The 2 best products ever made in my opinion. Sta Bill is the BEST product ever made for keeping gas fresh. I use it in everything from my chain saw to my motor on my bass boat. Awesome stuff. I've used Marvel Mystery oil since the early '70's and it's a miracle in a can!
My bet is varnish on the guides and stems. Also huge fan of Stabil and Marvel. We go through a lot of air tools because I absolutely forbid oiling them (I buy them) when we are reassembling a car or truck until priming and painting is all done. WD 40 and Armor All are not allowed on the property. They make fish eyes that are paint job killers. The Marvel seems to get a little better longevity out of the tools and it smells better. I tell the guys it's so good that I might just mix it with vinegar and use it on my salad.
Okay, this is going to sound totaly off the wall, but as far a crap gett'n all varnished, here is what you can do to take care of that. first drain your oil. Replace the oil with some diesel. Yes you read that right... start the enginel but DO NOT DRIVE IT!!!! THE ENGINE CAN NOT BE UNDER LOAD!! let the engine warm up to temp (maybe 10 minutes max) and then turn it off. drain all of the diesel out, and replace with good synthetic oil and a new filter. The diesel works to break down any varnish that has built up over the years. This may sound insane, but it works and I have never had a problem with this. You will want to give the truck a second oil change shortly after you do this. Call me crazy, but it works.
Crazy...yeah, you! Waddya expect??? You told me to do it. Sounds interesting. Never heard of that one before. Diesel instead of oil? That would scare me too much just THINKING about it. Andy
Internal Engine Cleaning Well ; here's the deal : one teaspoon of Diesel fuel will ruin the lubricity of a 55 gallon drum of oil . Yes , Diesel is a killer engine cleaner but you'd best make 1000 % sure you get every drop of it out else you'll either kill the camshaft or drop a rod bearing . It's possible to clean with Diesel fuel but just using synthetic oils obviates the need to do this . You all know I recently bought another old Mercedes Diesel , the DPO didn't change the oil much in the last 10 years as he didn't drive it anymore so when I got it home and pulled off the rockerbox ,I found sludge and lots of it so I immediately began using synthetic 5W-30 oil in my routine 3,000 mile hot oil & filter changes . Saturday I jacked the car up and removed the oil pan as it had a crack , the inside of the engine was squeaky clean , as-new ~ there was no film of black slime like any normal 27 year old car would have , just clean & bright metal everywhere I looked . You cannot imagine the detergent ability of synthetic oils untill you've used them in an old engine then opened it up.... It's also possible to use a quart of ATF in your engine a day before you're going the change the oil , that'll clean it out too and no worries about oil contamination . BTW : yes , I've used Diesel fuel to both clean out and un stick long dormant engine many times but the warning about no load when the oil is contaminated with Diesel , is no joke .
