2004 wj 4.0 oil question

[weaponoffreedom]

Probably because it was soaked in a clean hydrocarbon of any sort.

you must be right as always...............thanks

 

[Pak713]

Holy crap fellas lol. I wasn’t expecting this many replies so I don’t know where to start.

Like I said I’ve only owned it a year and I’ve put tons of work into. I think I’ve put maybe 6k-8k miles on it in a year. But like I said in the summer it sits at the cabin and I drive my truck as a daily. It runs good. I do realize the 4.0 is a noisy motor but upon the fresh oil change yesterday it was noisier than usual. This morning when I left for work it was back to normal noisy and it was about 35 degrees here this morning. I had a issue with the oil pressure sensor on the way home from our cabin last weekend but that’s an easy fix. The diaphragm in the oil pressure sensor must be gone because it’s leaking into the connector. Have yet to replace it. Oil pressure dropped to zero on the gauge on the way home even though the engine sounded fine.

I’d say half throttle the noise is still there no doubt. I’ve heard and read about the cracked skirts and also read about wrist pin issues. My first ever 4.0 Cherokee. I got it to be my woods trail, not drive my truck everyday vehicle and winter ride. I really do like it though. Even though it has 184k on it and it’s awd it gets better mileage than my truck. Around 20mpg on the highway. If y’all recommend that 5w40 better than the rotella 10w30 I’m not opposed to switching at all. If and when I get close to a 1000 miles left on the oil change I may run something in the oil and then change it. I think that’s one thing we didn’t do to it with all the work that went into it to make it road worthy again.

Appreciate the replies everyone.

 

[OVERKILL]

There is no pcv "valve"

There's a CCV connection:

Yes excuse me, intake valve, on the compression stroke, worded it wrong, either way, it solved the issue. ATF flush.

Intake valve would let air back into the intake, it would not end up in the crankcase. The only way for anything to enter the crankcase is either through the fresh air inlet or CCV, or going past the rings. The two valves, intake, leads to the intake, and exhaust, leads to the exhaust. If either leaks, that's where things end up.

Stuck rings on 6 does not create pressure in the valve cover, a non seating valve would.

If you have combustion byproducts getting by the rings, they end up in the crankcase, that's the definition of blow-by, combustion gasses blowing by the rings. If the crankcase gets pressurized by blow-by gasses, either due to them being in excessive abundance or a defective crankcase ventilation system, this is generally detectable and what you've described occurred.

A non-seating intake valve would result in compression and combustion gasses ending up back in the intake manifold, not in the valve cover.

Yep soaked in ATF did the trick.

I suspect the thinner lubricant (ATF is generally thinner than oil) might have helped slightly un-stick the rings. However, since that hole is down compared to the others, it sounds like you still have a problem.

 

[weaponoffreedom]

There's a CCV connection:
View attachment 185981

I suspect the thinner lubricant (ATF is generally thinner than oil) might have helped slightly un-stick the rings.

ah ha, so the atf could be of use huh, which was the entire point..........wow what a waste of time.

Where is the PCV valve in your drawing? I dont need one as I have 2 4.0s, byt nice drawing though. thanks

 

[weaponoffreedom]

Holy crap fellas lol. I wasn’t expecting this many replies so I don’t know where to start.

Like I said I’ve only owned it a year and I’ve put tons of work into. I think I’ve put maybe 6k-8k miles on it in a year. But like I said in the summer it sits at the cabin and I drive my truck as a daily. It runs good. I do realize the 4.0 is a noisy motor but upon the fresh oil change yesterday it was noisier than usual. This morning when I left for work it was back to normal noisy and it was about 35 degrees here this morning. I had a issue with the oil pressure sensor on the way home from our cabin last weekend but that’s an easy fix. The diaphragm in the oil pressure sensor must be gone because it’s leaking into the connector. Have yet to replace it. Oil pressure dropped to zero on the gauge on the way home even though the engine sounded fine.

I’d say half throttle the noise is still there no doubt. I’ve heard and read about the cracked skirts and also read about wrist pin issues. My first ever 4.0 Cherokee. I got it to be my woods trail, not drive my truck everyday vehicle and winter ride. I really do like it though. Even though it has 184k on it and it’s awd it gets better mileage than my truck. Around 20mpg on the highway. If y’all recommend that 5w40 better than the rotella 10w30 I’m not opposed to switching at all. If and when I get close to a 1000 miles left on the oil change I may run something in the oil and then change it. I think that’s one thing we didn’t do to it with all the work that went into it to make it road worthy again.

Appreciate the replies everyone.

Yes I recommend 5w40 I use it a most everything I have, except for my 4 wheelers.

Amazon.com

It is one of the best engines ever made............if you look hard enough you will find bad reviews on all engines. Try a different oil and report back.

It it may not make much difference, but whats the hurt?

 

[Twinturbski36]

I have 243k on mine. They like the winter but not until they warm up. I use 5w 30 and 10w30 at 3k -4k OCI . Just did plugs and coil. The thing runs great still!

 

[Pak713]

I’ll try the oil next time around here. Thing is great in the snow no doubt. Just as good if not better than my truck. My list is quite extensive on this jeep as far as parts. But I ended up getting it for free. Good friend of mine who I do a lot of work for.

 

[weaponoffreedom]

I’ll try the oil next time around here. Thing is great in the snow no doubt. Just as good if not better than my truck. My list is quite extensive on this jeep as far as parts. But I ended up getting it for free. Good friend of mine who I do a lot of work for.

thats a keeper

 

[Pak713]

When you’re talking about 5w40 are you talking T6? Or a conventional 5w40? As stated I’m running t4 conventional currently.

 

[weaponoffreedom]

When you’re talking about 5w40 are you talking T6? Or a conventional 5w40? As stated I’m running t4 conventional currently.

if you click on the link of my previous reply it will show you. Valvoline premium blue full syn 5w40, it is SN rated. I do not think that 5w40 rotella is S rated anymore.

 

[OVERKILL]

ah ha, so the atf could be of use huh, which was the entire point..........wow what a waste of time.

It's not the fact that it's ATF, it's that it's thinner. Using the same amount of something like 5W-20 or 0W-20 would have achieved the same thing, and not diluted the additive package of the oil like the ATF did.

Where is the PCV valve in your drawing? I dont need one as I have 2 4.0s, byt nice drawing though. thanks

CCV (Crank Case Ventilation), it's the fitting that the arrow points to where it says "CCV hose". It's not a PCV (Positive Crankcase Ventilation) valve in this instance; there's nothing preventing air from coming back in the valve cover from the intake manifold, which is how it functions with a PCV, the valve only works one way.

My understanding is that it's a fitting with an orifice in this instance, which limits airflow to/from the intake. The orifice may sometimes plug up, stopping the CCV from working.

 

[weaponoffreedom]

It's not the fact that it's ATF, it's that it's thinner. Using the same amount of something like 5W-20 or 0W-20 would have achieved the same thing, and not diluted the additive package of the oil like the ATF did.

CCV (Crank Case Ventilation), it's the fitting that the arrow points to where it says "CCV hose". It's not a PCV (Positive Crankcase Ventilation) valve in this instance; there's nothing preventing air from coming back in the valve cover from the intake manifold, which is how it functions with a PCV, the valve only works one way.

My understanding is that it's a fitting with an orifice in this instance, which limits airflow to/from the intake. The orifice may sometimes plug up, stopping the CCV from working.

right, in your oppositional post you said "PCV valve" which the 4.0 does not have, it has a hose, and a breather assembly in the valve cover, which is useless. To your point, they do get clogged, if you don't change your oil. I am sure than todays oil would do much better than old sj

See how dumb a pointless correction is?

Could it not be the difference in oil formulation that cleans up another aggressively? Lets say you use Valvoline, and the chemistry between that and Pennzoil is different, could the chemistry between the two act to clean what the other leaves behind?

 

[kschachn]

Could it not be the difference in oil formulation that cleans up another aggressively? Let’s say you use Valvoline, and the chemistry between that and Pennzoil is different, could the chemistry between the two act to clean what the other leaves behind?

Not really. It’s pretty well established science what “cleans” and what does not clean in a motor oil. It’s not a black art.

 

[weaponoffreedom]

Not really. It’s pretty well established science what “cleans” and what does not clean in a motor oil. It’s not a black art.

So a motor oil would clean what it left behind? If that was the case, would it leave anything behind in the first place?

 

[OVERKILL]

right, in your oppositional post you said "PCV valve" which the 4.0 does not have, it has a hose, and a breather assembly in the valve cover, which is useless. To your point, they do get clogged, if you don't change your oil. I am sure than todays oil would do much better than old sj

See how dumb a pointless correction is?

Not really. I asked you a question about the PCV valve being stuck (in this case, it would be the CCV orifice being plugged, but the end result would be the same), because you were saying the valve cover was pressurized. The only way that happens is through the crankcase ventilation system either being overwhelmed, or not working, the name of that component is immaterial to the question being posed.

Could it not be the difference in oil formulation that cleans up another aggressively? Lets say you use Valvoline, and the chemistry between that and Pennzoil is different, could the chemistry between the two act to clean what the other leaves behind?

Doubtful, none of them have the components necessary to really perform any sort of cleaning. Engine oils (and ATF) aren't formulated to be cleaners, they are formulated to keep their applications reasonably clean, at the price point they are blended at. This is what dispersants and detergents do.

I suspect, but obviously don't know for sure, that this was a byproduct of viscosity. The lower viscosity fluid was able to dislodge something that the heavier oil couldn't. That said, that hole is still down compression compared to the others (based on the numbers you've provided) so something is clearly still going on there.

 

[weaponoffreedom]

something is clearly still going on there.

yes, it needs a new engine.

recently, I ordered a new AX15 (separate issue) from japan, but it will not get here until whenever. Centerforce clutch. Was thinking about replacing the engine with an S&J reman unit. It would be easier to do it while the transmission was out. not sure. Then I would have a new jeep, (real jeep) for 5k

 

[OVERKILL]

yes, it needs a new engine.

Aw, that's unfortunate. Is it just that hole being down compression that has you thinking that? Have you done a leakdown test on it? I know it's got reasonably high miles, but these are generally very long lasting.

recently, I ordered a new AX15 (separate issue) from japan, but it will not get here until whenever. Centerforce clutch. Was thinking about replacing the engine with an S&J reman unit. It would be easier to do it while the transmission was out. not sure. Then I would have a new jeep, (real jeep) for 5k

I assume S&J is more reputable than an outfit like Jasper? lol. I had a Centerforce DF on my 5.0L fox body, it was a fantastic clutch, so can understand why you'd go that route.

 

[weaponoffreedom]

Aw, that's unfortunate. Is it just that hole being down compression that has you thinking that? Have you done a leakdown test on it? I know it's got reasonably high miles, but these are generally very long lasting.

I assume S&J is more reputable than an outfit like Jasper? lol. I had a Centerforce DF on my 5.0L fox body, it was a fantastic clutch, so can understand why you'd go that route.

There is an external coolant leak from the head toward the rear, slight crack i think. verified with pressure test. Runs and starts good, doe not overheat........no coolant in oil, or oil in coolant. Part of me wants to run it until it blows, but the other part wants one big rebuilding operation not two.

Jasper is good, but they do not sell to individuals as far as i understand, S&J has a 7 years 100k warranty, and they pay labor in the warranty aswell, even if you do it yourself.

I plan to quit my plumbing and start a repair shop\car sales sometime in the next year. I cant do construction forever.

rebuilt auto engines 1991 Jeep Wrangler

SandJ Engines - 1(800)942-7800-rebuilt-auto-engines-1991-Jeep-Wrangler

www.sandjengines.com

 

[OVERKILL]

There is an external coolant leak from the head toward the rear, slight crack i think. verified with pressure test. Runs and starts good, doe not overheat........no coolant in oil, or oil in coolant. Part of me wants to run it until it blows, but the other part wants one big rebuilding operation not two.

Jasper is good, but they do not sell to individuals as far as i understand, S&J has a 7 years 100k warranty, and they pay labor in the warranty aswell, even if you do it yourself.

I plan to quit my plumbing and start a repair shop\car sales sometime in the next year. I cant do construction forever.

rebuilt auto engines 1991 Jeep Wrangler

SandJ Engines - 1(800)942-7800-rebuilt-auto-engines-1991-Jeep-Wrangler

www.sandjengines.com

We've had a few members with bad Jasper experiences on here. @mrsilv04 has had several different engines, his saga is well documented, it was quite the epic. That's why I asked about the reputation. So, if S&J is better than them (which it sounds like they are) then you are probably G2G.

We've had a few good local machine shops around here that did fantastic quality rebuilds, but I know that's not always an option, depending on your location.