I don't really know what you're rambling about. Mine consistently goes 80mph sitting at ~3750rpm for hours with no problems. 4.0s can handle pinging the limiter for longer than you can stand as far as I'm concerned and have experienced.
Engine Sputtering on 1999 4.0 Automatic
- Thread starter 99’ TJ
- Start date
I don't really know what you're rambling about. Mine consistently goes 80mph sitting at ~3750rpm for hours with no problems. 4.0s can handle pinging the limiter for longer than you can stand as far as I'm concerned and have experienced.
bohuggabee
TJ Enthusiast
No they dont. The engines arent balanced. Its an inline. You are going to ruin your engine soon enough. Think of me
Inline 6s are the pinnacle of balanced conventional combustion engines. Perfect primary and secondary balance with 7 bearings to prevent flex. What is your definition of balanced if not an I6 or V12?
bohuggabee
TJ Enthusiast
My 4.0 had ruthless knock till i added 4 hole injectors. Its butter smooth now. But before. If i went above 2,000 rpm. The torque and the knock would rock your brains in the cabin. A truly balanced engine is a boxer or flat 6. Thats the smoothest engine ive ever driven. The power train and increase of rpm is just unprecedented. And i know drive train torque is separate on the chassis. But still.
You may think the engine wasnt ok... no it was completely fine. It just was more like a shaker from the 60’s.
Also, boxer’s can be used uniquely too. With two drive shafts for awd. No ones designed it yet but you can have two torque converters functioning like a differential that distribute the rotational torque and make the engine even smoother.
I don't know what you're rambling about. A flat 6 still has primary imbalances unless fork and blade con-rods are used, which I know no major car brand using for their flat motors. The only advantage a flat 6 has over an inline is less torsional imbalance due to a shorter crank, but the 4.0s is minimal due to 7 main bearings.
Your 4.0 having "knock" before adding 4-hole injectors sounds like another issue contributing to non-atomization of fuel. The 4.0s power band is within the 2000rpms and I don't see a company making an engine that "knocks" in it's power band where it's supposed to be driven at.
bohuggabee
TJ Enthusiast
Then what are you talking about? Because yes the flat 6 is going to have natural counter weight from opposite torsion of the pistons.
bohuggabee
TJ Enthusiast
Maybe im saying knock wrong. How do you interpret knock? Its a sound when i start my jeep. Its been there since i bought it. Its never worse. Sometimes better. Its an idle knock. Once it warms up. Its gone. Drove today. It was buttery. Just fine. Its a fairly typical sound from these engines.
I'm trying to prevent the spread of misinformation by you of saying an inline 6 is not balanced and shouldn't be driven over 1,500 rpm. The 4.0 was made to run at 2,000-3,000rpm all day long on the highway. That's why they put the 32rh in there to begin with. There is nothing wrong with running 80 even 100mph on these things so long as you keep them cool and aren't hitting rev limit. The TJ isn't some piece of trash that can only go 55 before everything explodes and dies. AMC knew what they were doing when designing this engine. Your misunderstanding of fundamental engine design is not helping this thread. The OP has an actual issue not related at all to driving too fast.
bohuggabee
TJ Enthusiast
You people... im not some idiot or half wit. Ive driven my tj for 40,000 miles. It has 163,000 miles on it with all original parts except a couple sensors. Can you say the same ?
You clearly dont understand torque vs hp in how it wears an engine.
bohuggabee
TJ Enthusiast
How much was rebuilt? We are both pursuing the same solutions. Better jeeps. Longevity
Plugs, sensors, and distributor. Replaced my timing chain when checking it just because I wanted to while I was there, not because it was bad.
bohuggabee
TJ Enthusiast
My timing is still original. It will probably need work too. It will take 6 more years to tell you otherwise. My belt is 13 years old and looks fresh. The way i drive doesnt cost money. My brakes need replaces now because of scenarios... but if i didnt have to live in it. It would still be spot on. I had to weigh mine down with 1,200 lbs of music gear and sleep in the driver seat. It ruined my brakes and a bearing from people with small suv’s having 4 wheels disc brakes that can look around properly
Just seen your edit. Lifter tick or exhaust leak at the manifold gasket. Can't tell based on reading. Common non-issue with 4.0s
You clearly haven't drove anything over 200hp. Stop talking endless bullshit that has nothing to do with the OPs problem
bohuggabee
TJ Enthusiast
Checked manifold countless times. Its a drive train thing that is common for these. Its always been there. The engine will start. It runs smooth after. It has other issues but
bohuggabee
TJ Enthusiast
Now youre useless. Hp vs torque? You dont even have a “i need to explain the difference on power train wear” explanataion?
I have no need to explain why driving a car wears parts out. I'm pretty sure the OP realizes that since something is broken.
I especially don't need to explain anything to someone trying to argue that an inline 6 is not inherently balanced and that driving over 1500rpm is bad.
bohuggabee
TJ Enthusiast
Then dont talk... you replied asking questions and people asked questions back. You then stopped answering them like an ai trolling under a bridge that has no river
Can you understand how a circle makes power?
Can you understand that nobody asked you about how you drive your fucking TJ? As far as I know, a 2 dimensional circle doesn't make any power and has fuck all to do with the OPs problem. Go back to trolling other places on the internet and stop spewing bullshit.
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