Valve retainer damage :/

[vling]

I got my 71 240Z started for the first time today. It idled around 1000 rpm (very rough) and the engine was shaking kind of bad, and a loud ticking noise coming from under the valve cover. I took it off to investigate, and this is what I found.

The lash pad was sitting on the floor of the head and looks to be fully intact. The valve spring retainer on the other hand was mashed up a bit and is a little tight for the rocker guide to fit into.

If I want to get the spring retainer off, I'll have to take off the camshaft and rockers, because I only have one of those universal valve spring compressors that gets blocked by the camshaft. My question is, are there any ways around having to pull off the camshaft to get this issue sorted out? (grinding part of the lash pad to make it fit?)

Edited July 31, 2009 by vling

[yetterben]

I would pull the cam man. I am sure there is gonna be some scars on that lobe. Sucks but no need to half arse it. If you have some cash just get all enw springs and retainers. Thats what i would do anyway fwiw.

[zKars]

Have you considered why this happened yet? If that valve is bent or stuck you have more problems than replacing a retainer. Search here for Valve seal replacement threads. They give techniques for holding the valve closed with the head on, but seriously, understand what is up with that valve before re-starting.

[rxsleeper]

Is the rocker broken? Thats what it looks like to me. IF it is just the rocker and spring clip, replace the lash pad, if it is undamaged, adjust the pivot post so that the rocker will slide back into position, reinstall the spring retainer, adjust valves to cold settings, crank car warm and re-adjust valves. From your picture, the valve has not lost a retainer and I would guess that you have not damaged the valve or head.

Best way to check is to perform a leak down test and see how that cylinder tests. I have slung rockers off of the race car head and finished a race with it. No significant damage, replaced the rockers/lash pads/spring rocker retainer and continue to use the motor. Not the best way but certainly doable.

YMMV

[vling]

rocker was fine. I ended up tapping the lash pad back into the spring cap. it went in without much effort and swivels freely in it's seat. i put the valve cover back on and started it, and much of the shaking and the loud noise from that area are gone, but there is still another clicking noise somewhere (sounds loud around the carburetors, but I couldn't find it while listening with a screwdriver). I'm gonna do some more searching for it but I had to stop before I got asphyxiated by the fumes in the garage

Also gonna adjust the valves very soon since that one has popped off before.

[FastWoman]

Is your fuel fresh? You'd be surprised how fast it can turn to a gummy syrup when just sitting. Then it will gum/glue your valves in place, causing exactly the problems you describe. I've had that happen with a 280Z I let sit up for about a year. This happens especially if you run the engine on the old gas (and it will seem to run "OK") and then let it cool off (which lets the hot gum solidify). In any event, I checked a previous post of yours, and you talked about a stuck valve. Be VERY CAREFUL when your valves are stuck, because they can collide with the pistons, and your valve train can fall apart (as happened to you).

I'd recommend pulling the valve cover and the intake manifold and cleaning/freeing the valves from both sides with a strong solvent, working them manually. Run the engine again only after you've resolved the sticking valves.

[vling]

Fastwoman - the fuel was fresh, less than a week old. The PO said the car was sitting for 2 years, so I replaced the fuel tank, pump, filter, and hoses. I'm sure some of the leftover old fuel could have caused the sticking though. I'm not sure if my valves were sticking, I just know that the rocker/lash pad had popped off before.

What product do you recommend to use for cleaning the valves? Do I need to clean off the oil from around the valves before I attempt to clean them?

I do know that cylinder #4 (#6 intake was the one that popped off) is not firing for some reason, and it seems to be getting spark.

Compression was between 160-180 last time I checked (before it was running again) with the odd one out being #6 at 200

Edited August 2, 2009 by vling

[FastWoman]

Sticking/sluggish valves could definitely cause a cylinder not to fire. Maybe that's the problem. There could of course be other causes, like the injector not firing.

I clean a lot of things with Chemtool B-12. I don't know whether there's a spray version of this product. Some form of spray cleaner (a strong solvent) would be good for getting the product into tight areas (e.g. inside the valve springs). Find a product that attacks varnish, which is your culprit. You don't need to clean away the oil; the solvent will do that for you. You will need to mop up the solvent periodically to keep it from draining back into the oil pan (i.e. down the timing chain tunnel). If you park the car facing slightly up-hill, the oil and solvent will collect in the back of the valve area (away from the chain tunnel).

You might start the process by removing all of your spark plugs, so that you can turn the engine easily by hand. Spray down your valves, turn the engine, spray again, turn the engine, spray, etc. After you've seen that none of them are sticking with hand turning, then work them a bit faster with the starter. Don't turn the ignition on. Open your carb to full throttle, with the choke off. Disconnect the wire from your ignition coil to your distributor (just in case). Clip a wire to the solenoid of your starter. When you touch the other end of the wire to the + of your battery, the motor will turn. Do this very carefully (!!!!). I don't know if the motor will turn fast enough to sling any oil out of the valve area, but be aware of mess potential. Spray the valves again, turn the motor (with the starter), repeat, repeat. Watch for wobbling rockers. Listen for any snapping sounds. If you see/hear/experience any of these things, STOP IMMEDIATELY, and return to working the valves by hand. When you are convinced your valves are working freely under starter power, put it all back together, and start it up. If it runs OK, then shut it down.

Finally, put a quart of Rislone in your oil. I haven't used this product YET, but it comes highly recommended to me. It's extremely high in detergent and will work on your sticking valves. You might have to drain out a quart of regular oil to add the Rislone. You can also put a bit of B-12 in the gas tank. I've successfully cleaned injectors and intake valves this way, but it takes a bit of time and repeat treatments. Pack up some tools in the hatch (in case you need them), close the hood, and go for a very long pleasure drive. Don't get too far from home. Stay within towing range. Don't worry if the engine isn't running absolutely perfectly, as long as your valve train isn't falling apart and you're not hurting it in any way. Hopefully that will free up your valves for you.

One last note: I've never done this on a car with valves sticking as badly as yours. Others may be able to advise you from a standpoint of more experience. You should consider my advice only as a starting point but should probably research a bit further before actually trying anything.

Good luck!

Sarah

[richn100]

I had the same problem on a 1970 240z. It would throw a rocker off at startup periodically. My problem was loose valve seats. Took the head off. Three of the valve seats were so loose the they fell out of the head when the valve was opened. When the engine heated up the aluminum head would expand and lock the loose seats.

The Fix is expensive ... New seats for all the valves.