Death Rattle... aka I should've been listening

[toplessdottie]

So in the 10 years I've had my Roadster, I've heard about this "death rattle."
I'd hear a little "clatter" on start-up, but foolishly ignored it (after having a mechanic tell me it's nothing).

"I'd recognize a death rattle!" I thought.

Well now that "clatter" doesn't go away after start-up. And after investigating on this site, "death rattle & evil L" kept popping up.
So I opened up the valve cover.. and wow! My L bracket is nearly sawed through. I'm shocked it has not sheered off (I can't imagine how many metal shavings have made their way around). There is so much slack in the chain it's basically Zach Morris.

Needless to say I will NOT be starting the car until it's fixed. I should not have ignored the 1000+ years of expertise on this site. Listen to what fellow Datsun owners warn about... they are trying to save your a$$, and make your roadster experience as great as possible.

Thanks 311s members!!!! Had I not had this site, I'd have kept driving... and probably destroyed my GREAT running U20.

Besides making a fix, and installing new chains, is there any maintenance I should be tweaking while in the motor?

[greydog]

If its been that long, you may need sprockets. Jim Tyler (jt68) makes a beautiful setifneeded.
Maybe awaterpump too.
Dan

[tjp]

and new tensioner feet and chain guides.

[Gregs672000]

You will of course either want to cut off the L or replace the guide. Consider shimming the tensioner so it does not retract fully but still has some movement. I have an ignition kill switch that I use, allowing me to spin the engine 12 times or so before firing it. This helps build oil pressure to tension the tensioner, helps keep the chain tight before the engine spins a lot of RPMs. Make sure you use a gasket for the tensioner, but DO NOT cover up the oil feed holes or use sealer. I make my own out of VERY thin gasket material. I use locktite on the bolts.

As suggested, closely evaluate your gears, looking for "christmas tree" teeth (undercut so they look like a pine tree shape), strongly consider replacing them as they have come down in price a lot over the years and are probably better quality. I would go with an adjustable cam gear if you are comfortable. I believe with the optional shim/dowel kit you can set the cam to "stock" or adjust it if needed (mine needed it, but different cam, etc). Good thing is that you caught it before it blew up the engine!

[toplessdottie]

Excellent feedback! Thanks to everyone, including Paul Wells for our 45min phone conversation... on a Sunday no less!

I'm not too familiar with adjustable cam gears, so I'm not currently comfortable... but I'll research.

I'll also investigate these "oil feed holes." I'll be relying on my local hot-rod mechanic for these fixes, as I'm not even a shade-tree mechanic. With being a hot-rod guy (though he works on old Volvos too) I'll want to bring him as much intel as I can.

Thanks again.

[Gregs672000]

Just be aware, it's gonna need a head gasket, manifold gasket, front cover gasket, oil pan gasket, water pump gasket, may as well do the front cover crank seal, exhaust collector gasket. Since the head is coming off, you may want to consider new head studs or bolts (I use studs, it is not suggested to re-use head bolts as they do stretch and can break, but I have as have others). I hate to say it, but it won't end up being cheap. Since you are that far into it, I might consider freshening up the head if you feel the bottom end is solid... have them check the valve guides, seals, valves and seats (original exhaust seats are brass, newer are stainless), maybe recut the valves ("3 angle" as they say). Have the head checked for flatness, but if it needs to be cut ask about that here with us first as it will also likely need cam tower shims depending on how much it is cut. Sorry man!!!!!

[greydog]

Why would you pull the head greg? I didn't see anything about head gasket leak or issue.
Personally, I'd do nearly anything to avoid opening an engine that is running and working well.
When I replaced the chains on my car, I unscrewed the water pump studs, lowered the pan and pulled the chain cover.
Put it back the same way with no issues so far.
Dan

[toplessdottie]

Yikes!
Sound pricy.

I've got my new chains, guide, tensioner shoe kit, and oil pan/head/cover gaskets.

The car seemed to be running fine, I just heard and saw the evil L deterioration.
Could I take the approach GreyDog did?

[toplessdottie]

Well... at Paul’s advise, I looked at me gears. Looks like I’ve got some undercutting (bummer)

https://www.dropbox.com/sh/1qd7w2zlcarw ... c0aWa?dl=0

[greydog]

Thats a shame.
Suggest you resist the temptation to put the new chains on the old sprockets.
Not a good idea.
Dan

[toplessdottie]

Yeah... hard to resist. We're in PRIME roadster weather here in Dallas for the next month. But I think while replacing all the chain components, I might as well bite the bullet and have the engine refreshed like Greg said.

Is there anything you all think I should do while going this deep? Any hanging chads out there that I may be unaware of that would be good to address at the same time?

[greydog]

To me, there is a world of difference between putting sprockets and chains on the front of an engine and pulling the engine, pressure wash, honIng cylinders, fitting new rings and bearings, new oil pump, all new gaskets and seals, soft plugs, motor mounts,etc.
On one hand, its a days work and you're back driving. No big deal. On the other hand its hard to stop the "while Im at it" which means much more time and money fixing something thats not broken, just in case.
Of course, if you suspect or know a reason for a rebuild, that`s a different story.
If its not broken, why not fix the issue correctly, youll need the parts anyway, and get back to enjoying prime time in Dallas. You can rebuild it next fall if you still feel the need.
Dan

[notoptoy]

+1

[theunz]

Why would you pull the head greg? I didn't see anything about head gasket leak or issue.
Personally, I'd do nearly anything to avoid opening an engine that is running and working well.
When I replaced the chains on my car, I unscrewed the water pump studs, lowered the pan and pulled the chain cover.
Put it back the same way with no issues so far.

Dan

In stock configuration, the timing cover has studs on the top of it which go into the head. There is also studs on the bottom which go into the oil pan. Therefore you have to remove both the oil pan and the head in order to remove the timing cover, unless you're lucky and someone has already replaced the studs with bolts! The first time I replaced my gears and chains I replaced the top studs with bolts. Since the pan is easy to remove I left the studs there. Even with the top studs removed you need to be careful not to damage the part of the head gasket that sticks out from the block and seals the top of the timing chain.

[Gregs672000]

Aaaaah! I've been wanting to reply but I was having log-on problems and could only come on as a guest. Steve got me back on today! So, yes, the reason why I was saying you have to pull the head was just posted above by Mike. Also, there are two front cover locating dowels that require you put the cover on pretty direct, which can mess up the head gasket a bit. Can be done, but it depends...
If you can do it without pulling the head, by all means do so, especially since she was running so well. BUT, it may not go that way and one should be prepared for that now more expensive repair.

So, report back, let your mechanic know we're here to help if needed!