1981 Z22 Lifter Tick

[heyman421]

Hey everyone, i love the forum. Just entered the Datsun family, and have already found lots of great information here!

I was fortunate enough to have recently purchased a 1981 Standard Cab 720 with a remarkably low 28,000 miles.

Truck has some stumbling idle/off idle issues, which through this site I have informally diagnosed as vacuum issues (all original hoses.)

That aside, the truck runs absolutely great.

Anyways, she's got a ticking lifter. I can't honestly say with 100% certainty whether or not the truck has been ticking since i purchased it last week. It's one of those things i may not have noticed right away, but now that I've noticed it, i can't UN-notice it.

I've got the Haynes manual, which I'm pretty disappointed with compared to the Bently guide I had for my VW. It just attempts to cover such a huge spectrum of Nissan vehicles that it seems to refer to the original owner's manual and lacks some of the specifications and specifics that i require.

I'm assuming that the z22 still utilizes solid lifters. Could the lash need adjustment at 28k miles (I'm 100% sure it's legit. The title i received showed the truck as having 3k miles in 1991!) or could it be something as simple as varnish or carbon making the lifter stick?

I searched for ticking/sticking/tapping with little luck, so I'm assuming lifter/valve tap is NOT common with these trucks. What should my first move be? I don't want to risk the sticking valve being on the exhaust side and burning it (The truck has so much more life to live!) The tapping is VERY light, i only first noticed it one night when i sat in the truck idling and rolled the windows up. I just want to do something about it before it gets worse. My previous vehicle (2001 Jetta TDI ALH) threw a rod at only 73,000 miles, so i'm insanely paranoid about unusual noises.

Do additives, such as marvel mystery oil, lucas, or seafoam work? Or should I immediately tear into the valves with a feeler gauge? I've only ever owned vehicles with hydraulic lifters, so to be honest i'm not 100% confortable with valve adjustment, so I'd be out a few shop hours.

Anyways, thanks very much in advance, and thank you for the great forum.

Pic for views:



Edit:

I changed the oil and filter with 10w30 as soon as I noticed the ticking, and after about 60 miles or so, it hasn't stopped.

[fastboatman29212]

I just used Seafoam in my 1995 Nissan Pathfinder (I added 1/2 bottle to the engine oil) and I think I noticed immediate improvement. Today has been about a week and I think my tap is GONE! So as of now, I think Seafoam works. Well worth the small investment. IMO

[heyman421]

I'm thinking your pathfinder probably has hydraulic lifters. I GET how seafoam could help unclog passages in them and help them work better. I'm just having a harder time understanding what it could do for my solid lifters.

Did you put the seafoam in the oil or gas? Both?

I may try it yet, just on the off chance it saves me having to take the valve cover off and tear in.

[fastboatman29212]

I added Seafoam to the oil.

[PEZi]

start by seafoaming... then switch up to an oil that has a lot of zinc (most oils don't have enough for our older trucks because they are formulated for new cars that don't need as much)

[captainzeros]

I've got a 1981 factory service manual for my truck, if you want me to scan a few specific pages just lemme know what you need. Never done anything with valves myself though, so I wouldn't know where to start.

[heyman421]

Just a quick update.

Today i deleted all my vacuum lines minus the timing advance (Thanks for the tip, PEZi.) Idle is smooth, throttle response is 100,000x better off idle, and it's not running nearly as rich as i was afraid of.

Anyways, bought 2 cans of seafoam. Put 1/2 a can in the oil, the other 1-1/2 cans in the tank, and filled up with premium (someone said there's additional detergeants in premium.) I drove 20-30 miles, and now I'll let the truck sit over night.

I'll report back about the seafoam in the next few days, but if it doesn't cure the noise, i'm going to wait till i redo the exhaust to do any valve adjustment. I know for a fact i have an exhaust leak, and since the truck no longer requires emissions testing, i'm going to throw on a pacesetter, a $30 autozone muffler, and a straight pipe out the back. I watched a few videos on youtube of cars with cracked exhaust manifolds, or broken exhaust manifold gaskets, and it actually made a very metallic sounding tapping noise. Since it seems like an extremely uncommon thing for lifters to tick in these trucks, I'm willing to knock out some other existing problems with the truck, and rule everything else out first.

[PEZi]

(someone said there's additional detergeants in premium.)

depends on where you get the gas from... i personally only fill up with shell v-power... the nitrogen cleaning agents plus the typical detergents in it are the only thing i trust in my engine... plus i need premium in order to run the timing that i am

[Rev_D21]

Get a set of feeler gauges and check the lash on the valves. My old 81 Dat w/z22 would need semi-frequent adjustments. Failing to have them in proper adjustment would eventually cause the cam to become scored forcing the rocker arms to bounce each cycle around which makes a horrible clanking noise. Seafoam is great but I bet the lash is out.

[heyman421]

The seafoam didn't do anything. At all.

Ended up ordering a valve cover gasket (the reason it took so long to report back) and adjusting my valves. They were each a few thousandths off, but apparently enough to make the noise. Engine purrs like a kitten now. Tightened up the ignition timing, checked the chain & tensioner, and everything's looking nice. There's still a rhythmic tapping from the engine bay coming from the mechanical fuel pump just before the carburetor. It doesn't appear to be user serviceable, and i can't imagine any sort of damage it would cause when it fails, so i'm just going to leave it till it gets worse.

The trucks 80% of it's way to perfect now. There's a few quirky bits remaining, but i'm going to hold off on fixing any annoyances and quirks until the exhaust leak has been fixed in the next few weeks. I have a feeling most of the remaining gremlins are caused by a tear in the flex-pipe, and a clogged cat.

Considering this is a 29 year old vehicle, about $200 invested to bring it back up to my own personal standards and not a single day of drama, missed work, or being stranded seems fair. Hands down the most resilient little bugger I've ever owned or driven.