MOS2 vs. Tappet Stop Noise

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428
Location
Florida
I also have an issue similar to this. I have a 95 nissan 4cyl pickup truck,and when I start the engine it makes a rattling noise for about 5 seconds,and then it goes away. I wish I could resolve my issue too.
Originally Posted By: dlundblad
My Jeep ticks slightly a few moments after start up, but eventually stops once warm. PYB and an OEM filter has helped for the most part, but I want more. Would any of these products help with my issue? http://www.liqui-moly.com.au/products/oil-additives/
 

CT8

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15,392
Location
Idaho
It takes time for all the hydraulic thingies to fill to operating pressures and fills. Air displaced etc. The oil in the engine drains out of the passages and bearings and hydraulic lifters when the engine is off.
 
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2,943
Location
Georgia/Retired
lawnguy, the issue with your Nissan is possibly (likely) the timing chain. My 1997 would rattle on start-up and I let it go for years. It finally got to the point that I was afraid it was going to damage the engine so I took the timing chain cover off and found that my timing chain guide had disintegrated. The chain was OK but the guide has a plastic cover over the metal guide and the plastic piece was found in the oil pan. The chattering noise was the chain slapping the metal guide until oil pressure took up the slack in the chain.
 
In my case MoS2 didn't quieten my noisy lifters at all and mine are noisey even when the engine is at full temp at low revs. I still add it because it makes the engine much quieter and smoother in general and it's always good having that extra protection. The only thing that has ever quietened my lifters is using thinner oil (opposite of what everyone recommends when quietening lifters!) I think this is because there are slight blockages in the oil passages in or leading to the lifters. 10w40 makes them rattle a lot, 10w30 makes them almost silent, maybe because the thinner oil can make it's way into the lifters easier where the thicker stuff can't
 
Messages
4,638
Location
Massachusetts
Originally Posted By: CT8
It takes time for all the hydraulic thingies to fill to operating pressures and fills. Air displaced etc. The oil in the engine drains out of the passages and bearings and hydraulic lifters when the engine is off.
It doesn't take that much time. Given that the valve train is non-adjustable, it is likely a case of cold parts. While I have never been a fan of stock Jeep oil pumps ( I use HV pumps in my trail Jeep and buggy), they still provide adequate lubrication to the top of the engine when cold. As soon as you start cranking the oil pump is starting to pump. Years ago, a member named BuickGN and I did some observations of thicker oils below freezing temps. I fired up a cold Jeep 2.5L well below freezing with Delo SAE30 and had instant flow from the rockers. BuickGN was running 20W50 and observed the same. Jeep engines are an inherently noisy design. They are mass produced cast iron block and head with non adjustable valve trains. If the OP's engine only makes a bit of noise for a few moments when cold, he should consider himself lucky. Just to comment too, that oil does not completely drain from bearings when the engine is off. I recently rebuilt a friend's Rambler 199 (the Jeep 4.0L's Grand Dad) which sat in a shed for 30 years and it had plenty of oil still in the bearings.
 

CT8

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15,392
Location
Idaho
I realize exactly how an engine oiling system works. Oil drains from the passages when sitting .I never said the parts were dry. The oil passages will drain when sitting for a period of time and hot oil we all know is like water . when you start up an engine that has been sitting all the air travels out of the oil passages before the oil that is the cause of the noise. Plus the hyd lifter bleed down a bit as well.
 

dlundblad

Thread starter
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13,085
Location
Indiana
Originally Posted By: Zaedock
Jeep engines are an inherently noisy design. They are mass produced cast iron block and head with non adjustable valve trains. If the OP's engine only makes a bit of noise for a few moments when cold, he should consider himself lucky.
First off, I meant minutes rather than moments. Its always quiet immediately upon start up for about 20 seconds, (this tells me my ADBV is working) then the tick starts for 1-2 minutes at idle. I imagine the time is less if I just get in and drive. I'm always easy on a cold engine btw. While it seems to be a fairly common issue on the web, I have yet to hear a 4.0 tick like mine on start up. Of all the 4.0s I've heard fire up in parking lots, they were all tick free. Heck, my dads Renix 4.0 is quieter than mine with the exception of the exhaust. I understand they aren't as quiet running as say a late model Civic, but the ticking is just plain odd. I guess some Jeeps have it.. some don't. I need to replace the valve cover gasket and PCV. Maybe once the cover is off, I can feel for loose lifters. Either way they don't seem to hurt anything besides my mental health.
 

dlundblad

Thread starter
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13,085
Location
Indiana
Originally Posted By: OneEyeJack
Have you considered an exhaust leak like this?
This is a video I made last fall. This was with M1 10w30 HM and an M1 filter IIRC. Its a bit quieter now with the Mopar filter and the PYB, but same style noise nonetheless. Its funny though.. It always ticked right upon start up before with the other oil. Link
 
Messages
4,638
Location
Massachusetts
Originally Posted By: dlundblad
Originally Posted By: Zaedock
Jeep engines are an inherently noisy design. They are mass produced cast iron block and head with non adjustable valve trains. If the OP's engine only makes a bit of noise for a few moments when cold, he should consider himself lucky.
First off, I meant minutes rather than moments. Its always quiet immediately upon start up for about 20 seconds, (this tells me my ADBV is working) then the tick starts for 1-2 minutes at idle. I imagine the time is less if I just get in and drive. I'm always easy on a cold engine btw. While it seems to be a fairly common issue on the web, I have yet to hear a 4.0 tick like mine on start up. Of all the 4.0s I've heard fire up in parking lots, they were all tick free. Heck, my dads Renix 4.0 is quieter than mine with the exception of the exhaust. I understand they aren't as quiet running as say a late model Civic, but the ticking is just plain odd. I guess some Jeeps have it.. some don't. I need to replace the valve cover gasket and PCV. Maybe once the cover is off, I can feel for loose lifters. Either way they don't seem to hurt anything besides my mental health.
Precisely why I don't believe it's an oil flow issue as another poster stated. It is more likely an issue with a lifter or again, a rocker arm. I can't tell you how many Jeep engines I have built for myself, friends, and customers over the years. One thing that has always blown me away is the variance of the stock rocker arm ratio and geometry. I'll agree on the Renix engines being the quietest. My kid's '89 XJ is quiet as a mouse and as the body nears retirement, I may keep the chassis for another buggy build or zap in some new body panels and keep motoring on. That reminds me of a customers 1998 TJ. It's super clean with a Clayton long arm on 33's, but with only 75,XXX miles on it, sounds like a flippn' sewing machine.
 

dlundblad

Thread starter
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13,085
Location
Indiana
It cracks me up how they vary in noise. My brother's boss let him borrow his '99 TJ for a few weeks. That too was very quiet.. just over 100,000 miles and short tripped to death. It gets driven maybe 5 minutes to and from work if that. The body is all rusted to heck and the vinyl doors were falling apart, but that engine was beautiful sounding even with the noisy mechanical fan. At roughly 1000 lbs. lighter than my Jeep, it sure had some get up and go too. The transmission was noisy though.. Lol Just Napa dino and Napa filters its whole life.
 
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2,362
Location
Texas
Originally Posted By: OneEyeJack
Have you considered an exhaust leak like this?
+1 OneEyeJack wasn't blowing smoke when he mentioned this. The exhaust manifolds are known to crack, warp, and the mounting bolts can come loose. To the untrained ear the noise sounds like a lifter or lifters ticking, and in many cases the noise will go away when the manifold warms up. Rambler 6cyl engines have had this problem going all the way back to the 60's.
 
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8,129
Location
Mahzurrah!
Mine starts the "rat a tat tat, rata tat tat" about 20-30 seconds after start up too. It does it for several minutes but quits if I put it in gear. Nothing I have tried has made much difference and I have been far more focused on start up rattle anyway. My old XJ did not do it. Sounded (and still sounds like) a good ol 4.0 sewing machine when running. I am using MoS2 now in the WJ and have for a while in the past it has not had any effect on the rata tat tat but like posted above it does make for a quieter, smoother engine overall. If there is anything to put in the oil to correct it I am not aware of it.
 
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4,638
Location
Massachusetts
Wag is correct. Even the 2.5L four cylinder suffered from sheared off exhaust manifold studs (specifically, the front stud). Just Empty Every Pocket.
 

dlundblad

Thread starter
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13,085
Location
Indiana
I'll have to look into it. The noise seems to be more of an issue after oil changes or if I'm using a filter it doesn't agree with.. That's why I think it's internal.
 
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1,065
Location
MA.
One of my favorite engines of all time the 4.0 jeep straight 6. Easy to work on and tough as nails! And yes they make strange noise heck mine sounded like it had loose change in it until it was fully warmed up. Frankly I just ignored it and it ran fine till trade in at 210,000 miles. My mechanic has a Cheorkee with the 4.0 and it make noise as well it has several 100,000 miles on it. He tells me he will dump it when the motor dies he has said this every year for the last five years! If it really worries you then pull the valve cover and check it out its easy on this engine.
 
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