My Jeep has had a bit of what I think is lifter tick, audible between 2 and 3k rpm. No lifter tick on startup though. 

 

I plan on changing the oil (it's a diesel engine) and I've been thinking about what to add to the oil before changing it to help clear up the ticking noise. I've read that adding diesel fuel or ATF to the oil, running the car for a few minutes, then changing the oil helps. It's an old pushrod design and taking the heads off to remove the lifters would only make me get head studs, which I don't want to do right now. 

 

What are your thoughts on this? Seth ?

Seafoam

We don't have it here. So it has to be some sort of shadetree solution  

No seafoam that's crazy

You could try the deisel fuel as for the ATF I've seen people poor it in the intake on old carb engines to loosen sticking valves.

Before you do the ATF flush pull the valve cover and spray carb cleaner down the pushrod hole and let it soak in for a few minutes then do the ATF flush. Good luck. 

My son's Jeep 4.0 gas does that.

 

I use Shell Rotella along with a zink additive and it takes care of the ticking sound. http://zddplus.com/products/zddplus-oil-additive/

 

We also use this in the 38 Plymouth and 61 Fury.

 

So if all else fails give that try.

Oil company's stop putting zddp in oils since cars are roller lifters these days,zddp was important for old engines with flat tappet camshafts

Oil company's stop putting zddp in oils since cars are roller lifters these days,zddp was important for old engines with flat tappet camshafts

 

Yes sir, that is why we use it in the old show cars and was told it would work in the old Jeep motors for their tapping noise.

At 2-3K I doubt a cleaner will really help. If you don't have Seafoam available, tranny fluid will work wonders. As Neil suggested, use a Zinc additive. It embeds into porous metal allowing for smoother surfaces, reduced friction, reduced binding, etc. It will kill an O2 sensor and load catalytic converters, but on a banger you don't need to worry about either.

Thank you for all the advice, I will pour some ATF in the oil, run the car 15 minutes, drain and then I'll do another oil change in 3000 miles  

2-3k is right smack in the powerband (engine revs up to 5k). The lifters in the Miata tick occasionally on startup but it's a much much louder noise. 

 

I've never tried to listen for the noise when coasting, if it does it only when loaded I think it should be an exhaust leak and not lifters. 

 

Time to look for zinc additive...

2+2 products are available here, this is what I saw in a local parts store:

http://www.berkebileoil.com/motor-flush-2000.html

 

Might give that a try instead of ATF...

If its lifters then it'll be present without a load aswell. Could be an exhaust leak. You never know

I decided against flushing, going to change the oil in 1-2000 miles and switch to synthetic. Noise is still present, the harder I accelerate, the louder it is but it's barely audible when coasting. Will check injectors, pushrods, re-tighten rocker arms and if all else fails, the exhaust manifold comes off. 

Synthetic will make it louder. At least it will if its a lifter tick