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Eliminating the "tick, tick, tick"

ParadiseXJ

NAXJA Forum User
My 88 MJ has a tick, especially when cold, but it doesn't go away completely. I've put the stethoscope on the valve cover, nothing. It has a slight exhaust leak (proven when I seafoamed it) towards the rear of the engine. I stethoscoped the manifold, all the front components are new cause I've revamped the thing (water pump, alternator, A/C compressor, P/S pump, harmonic balancer).

So my question is: I know the AW4 has flexplate bolts that can work loose and cause a tick, but is the same with a 5 speed? Can the flywheel bolts work loose and cause the same tick?

OR

would the exhaust leak increase or decrease the tick
as it warms up?

Like I said I've run the stethoscope all around the engine bay, top end, oil pan, sides of block and cannot isolate the ticking. I've also changed the oil twice, seafoamed, MMO the first change to clean things out, Lucas oil stabilizer the second change. No difference in ticking.

When it's at operating temp the tick is less pronounced but still there at idle. When I'm reving or running the tick SEEMS to go away, but I know the ticks just get closer together and blend in with the engine roar. It doesn't seem to affect the performance of the engine, still runs very strong without any stuttering, backfiring etc.
 
I can hear the ticking from the injectors with the stethoscope and they're much faster than the ticking I can hear with the "naked ear". Like a hummingbirds heartbeat.

Like t-t-t-t-t-t-t-t-....as opposed to tik-tik-tik-tik.

Unfortunately it sounds like the ticking purge cannister like newer models, but I don't have a newer model.
 
Sure you're not hearing piston slap til the pistons warm up and expand? My 90 Comanche does this. 4.0s are notorious for piston slap.

I could be. Anything's possible at this point I suppose. Is there anything that can be done to get rid of, or minimize it short of pulling the mill?
It's more annoying than anything else and I worry that I might be doing it harm to run it.

Oil's in good shape, WIX filter, top end is clean as a whistle.
 
I had that problem for years with my 87, 4.0, and tried everything. 5-90 gave me a clue one day that worked. It seemed my lifters were sticking. Running the engine at no load up to 3500 to 4000 rpm for 1-2 minutes freed up the lifters, and the noise went away. Had to repeat the step several times, especially after cold morning starts, but the noise is pretty much 99% gone now, and stayed gone the last 15,000 miles. Now at 278,000 miles.

Something about the 4.0 needing to get up over 3000 rpm periodically to un-stick the lifters, and get them rotating again.

Worked on my 89 last winter also when it decided to start ticking. It only has about 120,000 miles on it, and a new head.
 
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Mine went for years with out ever getting over 2400 rpm, from 2004 when I bought it, till about 2008. And who knows about the prior 224,000 miles before I got it. There were times when it was so bad, I was sure it was going to throw a rod. I had already tried years of snake oil tricks......Now it just purrs!
 
My Jeep has been running rough for several years. Purchased some BG44K recently after using it successfully on my Discovery 2, threw it in with 1/4 tank. Now it runs very quiet. Got it for $12 a can on e-bay. Its worth a try.
 
Running rough is not the same as running smooth with a tick tick tick valve clatter sound.

My was so bad on cold morning starts it sounding like a hammer striking the valve cover 1-2 times a second. hasta

BG44K is good for cleaning fuel injectors!
 
check your header for a crack... mine is cracked and makes a ticking sound...
 
harmonic balancer? mine would tick on and off. it was rubbing against the oil pan.
 
I had that problem for years with my 87, 4.0, and tried everything. 5-90 gave me a clue one day that worked. It seemed my lifters were sticking. Running the engine at no load up to 3500 to 4000 rpm for 1-2 minutes freed up the lifters, and the noise went away. Had to repeat the step several times, especially after cold morning starts, but the noise is pretty much 99% gone now, and stayed gone the last 15,000 miles. Now at 278,000 miles.

Something about the 4.0 needing to get up over 3000 rpm periodically to un-stick the lifters, and get them rotating again.

Worked on my 89 last winter also when it decided to start ticking. It only has about 120,000 miles on it, and a new head.

My 90 MJ has had a cyclical lifter click at idle and I've tried all the snake oil treatments but nothing worked. Yesterday I tried 5-90's suggestion and it was gone after the 3 minutes at 3750 RPM. I'll keep you posted as time goes on.

BTW Mike, you never went over 2400 RPM for that long of time?
 
My 90 MJ has had a cyclical lifter click at idle and I've tried all the snake oil treatments but nothing worked. Yesterday I tried 5-90's suggestion and it was gone after the 3 minutes at 3750 RPM. I'll keep you posted as time goes on.

BTW Mike, you never went over 2400 RPM for that long of time?

Yep, 5-90 said there is something about the >3000 rpm area that gets the lifters to start rotating again, thus unsticking them.

I had a bad TCU side TPS that had it up shifting at 1200 rpm for years, before I figured out the TCU side of the TPS was bad, and the ground had 8 ohms on that side of the TPS as well, which had the TCU up shifting at 1200 rpm even at WOT:shiver:. So at 65 mph, it topped out at 2400 rpm on the engine.
 
No more tick as of yesterday. FWIW, I frequently am above 3000 RPM in daily driving so the coupla minutes held at over 3000 must be the trick. I went 3 minutes.
 
3500 to 3700 seems to be the sweet spot for mine. Takes less time if it is warmed up first.
 
Thanks guys, I'll have to try this. I've been outta town for the last week, and came back to rain (again). Looks like some decent weather ahead for my shade tree shop to re-open.
 
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