Jeff I indu Posted May 31, 2020 Report Share Posted May 31, 2020 This car ran great last fall. During the winter I started it and all at once it had a terrible miss and barely could keep it running. I thought it might be bad gas but just did a compression test and had crazy results. The first three cylinders had zero compression. The back three had between 115 and 120. I assume I have stuck valves. My book says to remove the right front wheel and the wheel housing panel to access the valve cover plate. Or would it make more sense to pull the head and inspect/lubricate the valves to see if they will seat first. This engine had a very smooth idle last fall. I dont know what could have caused 3 valves to stick at the same time but right now this is all I can think of. The oil was changed last fall also. Is it possible to access the top of the valves through the spark plug hole and press downward to seat them? Would pouring a little oil in the sparkplug hole and cranking the engine over lubricate the valve guides and maybe get the valves to seat? Again zero compression in the first 3 cylinders double checked by using my finger to block the holes. Just looking for suggestions to start as I just found the zero compression issue a short time ago Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted May 31, 2020 Report Share Posted May 31, 2020 (edited) Sounds like stuck valves. I would spray some PB Blaster or equilvalent down the spark plug holes...let it soak for awhile....then crank the engine over a few times. Let it soak more...then see if it will start and run on all cylinders. If not you can sometimes push down the intake valves if stuck...carefully. Otherwise pull the tappet covers to try and wedge the stuck valves back down. New sitting engines not run much tend at times to get stuck valves. Is the engine a recent rebuild? Varnished gas also can cause valves to stick almost instantly. Nice car! Edited June 1, 2020 by Dodgeb4ya 1 Quote Link to comment Share on other sites More sharing options...
soth122003 Posted May 31, 2020 Report Share Posted May 31, 2020 Pull the wheel and the panel and check the lifter springs to make sure they are not broken. I doubt they are but it never hurts to check. With the plugs out, pour a little oil in the plug hole and let it penetrate and lube the valves stems and guides. Some people use automatic trans fluid for this. Your call. While it is penetrating, check the area with the valve cover off and see it the penetrate is coming thru. With the plugs out, you should be able to see which valve is open. You should be able to work the valve from the bottom to loosen it up. My guess is they just got stuck from setting over the winter. Joe Lee Quote Link to comment Share on other sites More sharing options...
Ulu Posted May 31, 2020 Report Share Posted May 31, 2020 If a valve is stuck open you will not be able to get a good leakdown test. I would do that before suspecting broken springs. If none of the cylinders leak fast at TDC it's not likely valves. But if one does leak, you will know what 2 valves to look at once you get the cover off. And which cover to pull. Quote Link to comment Share on other sites More sharing options...
Jerry Roberts Posted May 31, 2020 Report Share Posted May 31, 2020 I think that you are right that some valves are stuck . The easy way to find out is to pull the side covers and watch the valve stems / valve springs as the engine is turned over . 1 Quote Link to comment Share on other sites More sharing options...
nc plumber Posted June 1, 2020 Report Share Posted June 1, 2020 It's fairly common for some of the valves to stick open when an engine sits unused for a long period of time. I'd remove the plugs on the cylinders with the stuck valves and pour some Marvel Mystery oil in the cylinders and let it sit overnight. Adding some seafoam to the fuel would also be a good idea. Start it the next day and see if the valves are free. 1 Quote Link to comment Share on other sites More sharing options...
keithb7 Posted June 1, 2020 Report Share Posted June 1, 2020 I like the plan to remove wheel, and remove fender window. Remove valve covers. Have a friend crank then engine and watch the valves. Would spraying lubricant in there help? Maybe work a few valves and springs with a screwdriver? Get ‘em moving again? Quote Link to comment Share on other sites More sharing options...
Jeff I indu Posted June 2, 2020 Author Report Share Posted June 2, 2020 Thanks for the responses. Soaked the 3 cylinders in oil overnight, still stuck, soaked the 3 cylinders in pb blaster the second night. Pulled the valve covers today and it was easy to see which 3 valves were stuck. Popped them down but they are still sticking sometimes. No broken springs. Will continue to oil and crank for a few days until I know they are free. Got a new gasket ordered and she should be runni g smooth again soon Jeff 1 Quote Link to comment Share on other sites More sharing options...
RobertKB Posted June 2, 2020 Report Share Posted June 2, 2020 Easy fix. Glad you got it sorted. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted June 2, 2020 Report Share Posted June 2, 2020 personally I would remove the springs, pull the valves, wire brush the valve stems...use a good bore brush with solvent to clean the guide....reassemble....and heck I would more than not do that to all the valves, hand lap while there.....but I am always accused of overkill.... Quote Link to comment Share on other sites More sharing options...
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