For when I am looking tomorrow, is there anything that can be done if the spring is just loose in the seat? That is what it feels like to me. Is this even a problem other than the noise it seems to be making?

I just looked at the camshaft removal procedure....yikes.

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

I'll post some pictures so you know what you're getting into. I believe I have an entire valve assembly.

You'll understand better how the spring should be sitting and how the symmetry of the system does not allow for awkward spring movements unless something is awry.


When do you need this by?.... if you think it will help.

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Here are the two members that directly retain the spring.

The one on the left is the rotocap (RC) that sits in the head at the base of the spring, and the other is what we are currently referring to as the 'keeper'.

You are are looking at the underside of the keeper where the spring contacts. There is nowhere for the spring to go - if there is enough play for the spring to jump this lip... something is very wrong.

The rotocap acts a set of ball bearings for the valve / spring assembly - if you spin the keeper, everything should be moving together at the same rate.

You will also see that the RC has a very fair lip on it as well. It has some axial 'wobble action'. ie.. the top can tilt a little to compensate for spring irregularities.

There is really nowhere for the spring to go. Any normal, minor play between the inner diameter of the spring and the lips of these members is easily discernible from abnormal situation of unregulated movement.

Attached Thumbnails

 

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oohhh. Just had a moment.

If someone put the 'keeper' in upside down it could allow for excessive movement of the spring back and forth... but will not explain the looseness of the spring.

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jt20,

cool, that pic is incredibly helpful.

i do not have a ton of play, but it is significantly more than the other intake valves. the difference is I have enough play that I can move the spring enough in its seat back and forth to make the 'clicking' sound. the movement does seem to be at the bottom of the spring as opposed to up top near the keeper. i will have to check for a spring break at the bottom, that I think maybe the most likely scenario given the shape of that bottom metal part.

ill go and look more directly at it today, take some pics and try to get a quantifiable measurement on what's going on.

i do not think that this vehicle has had the valve train touched before. its not in the service records...i can give the PO a call and see. ill check if the keeper is inverted.

thanks again, i guess ill do some more poking. i hope this is indeed the sound and i am hearing and not a major coincidence.

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

I think that is a legitimate assumption. When I removed my head for thorough inspection / cleaning, I found lots of debris down in the bores of the rotocaps and they were not moving as they should have been.

I would not be surprised if one has failed, even at that mileage.

*another side note: if the car was stored for a very long period of time without running, it easy to imagine that the cam was left in the same position, depressing a couple of springs. This, perhaps, could flatten them out?*

ditto

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jt20,

I like the way this is going. Your hunch is correct, this car did indeed sit for a year before i bought it. before that it was owned by an 85 year old fellow who i think rarely drove it. I noticed this noise right away when I first started and drove that car.

The really good news is that I do not need to move the cam to get the springs out. Referencing FSM article 05-250,"Removal and installation of valve springs", all I need to do is remove the rocker arm assembly. Literally a few minutes more than where I am at now in terms of disassembly. So either way I'll take the spring out and replace it - and give the keepers a solid look.

Question: I know I need to move the #5 piston to TDC before I remove the spring or else the valve falls into the chamber (i know that means the head comes off ). Is it valid to line up the cam marks for #1 cylinder's TDC, observe the cam lobes position on cylinder #1, and then rotate the engine to replicate this same state on cylinder #5?

What else should I replace while I am in there on that valve, anything?

Hopefully Ill get a few minutes today to go take the rocker arms out and see what I can see. I am getting hopefuly that this will be it!

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

that is most excellent.

That is very clever. As a caution: use some thin metal wire and wrap it around the valve shaft threads and tie it to the spring before you remove both nuts. once you get the keeper off the top, push down on the valve to make sure it will contact the piston head in the event that it falls.

Usually, you want to replace everything on the head all at once. All the parts are 'broken in' together. The only things you should consider replacing are :
valve stem seals
rotocaps
springs
nuts (on the valve shaft)
*To be determined by your inspection of things.*

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Ok, got the rocker group off. Got the top cap nut off. Rotated to TDC of cylinder #5 by copying what I saw from #1 cylinder when cam marks lined up.

I am about to tie the wire as a safety net, but as I unscrew the lock (bottom) nut, the valve keeps falling down into the chamber, it seems to have not hit a bottom. I am getting nervous.

If I am truly at the TDC for that cylinder, how much should the valve fall?

dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Is it possible and safe to put the bottom counternut back onto the valve threads and use that as a stop?

Spin it all the way down so no threads contact the valve stem seal and fudge it up.


I can't answer the depth issue because you have only approximated what you saw with the cam relation. Your error there is doubled at the crank.

If you found TDC, it should not drop more than a centimeter. And thats a large overestimation.


Hopefully this is not in vain. Keep in mind you are chasing an apparition.

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I can't get the keeper off and spring off without removing the bottom nut. So far the valve has dropped about a centimeter or therabouts. I got the cam lobes approximately to what I saw on cylinder #1, maybe i should have been more exact?

What is happening is that I am unscrewing the lock nut, and as I unscrew it the valve drops down. I want to valve to stop dropping and the nut to travel up the threads, giving me some reassurance i have reached the bottom.

would it be logical to rotate the engine around and see if there is a point at which the nut is lifted, or is this a bad idea?

Im enjoying the wild goose chase. I now know approximately how to do valve stem seals if I choose to someday. I lost my job last week, so frankly im enjoying having something to do like this. But I DO NOT want to back into a valve job but dropping it into the chamber :-)

dd

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-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Don't add more confusion.

If your wire is tightly wrapped around the threads under the keeper - the valve will not drop.

take the keeper off and put your locknut back on and screw it all the way down by hand.

*does this sound safe to you?* and does it look like it will work?

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UPDATE: i was wrong before, all that is happening is that the spring is decompressing, the valve is not dropping.

but curiously there is no way to know if I do indeed have a piston under there.

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

push down on the assembly once the spring's load has been mostly relieved

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I was thinking that. But assumptions get us big trouble.

Its like when you're in a car, and another nearby starts moving your brain tells your body that you are moving... wiiieeerrrd

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