blistovmhz
NAXJA Forum User
- Location
- Vancouver, BC
So I've had issues with the 4.0L in my 98 XJ since the day I got it. Thing stuttered and just wasn't happy on a fairly regular basis. Owner said it was heat soak, I told him he was wrong but I'd take it anyway because he was only asking for the price of the stereo.
Turned out it was no compression in the #6 cylinder. Stuck intake and exhaust valves. This was like, 7 years ago when I knew nothing. Replaced the head (again, I didn't know better) and it ran like a top, but I was definitely losing coolant, but there was no evidence on the ground or out the exhaust. Of course, the long short is that I had a hairline fracture in the #6 cylinder, which was small enough to go unnoticed without magnaflux, but large enough that when water temp/pressure got up to around 100, it starts slowly pushing coolant into the cylinder.
So I figured whatever. I'd just let it run it's course and do something about it when it became a bigger issue. Well, now it's a bigger issue. Started losing power on the highway on hot days, and sure enough, I'm low on coolant, and the #6 plug is rusty, and I'm losing oil pressure, etc. The loss of power I'm sure is being caused by stuck valves again (derp) caused of course by the constant flow of water into the cylinder. I'm guessing the rings and cylinder walls aren't too happy about the constant wash either.
I figure at this point, there's no point in pretending the head will still be good without at least a new set of valves. If I have to buy a short block, and some valves, I'm already into the price range of a decent low mileage 4.0L. If I'm seriously looking at spending $400ish on a used 4.0L, maybe I should just spring for a brand new LB (someone selling one locally for $700). And ya know, if I'm talking about taking out the old power plant, maybe this can be an excuse for a v8 swap....
*sigh*
So:
1. Used 4.0L - $300-$450; No real good way to know the condition without actually buying and installing. I can compression test and inspect stuff all day, but there's just no way to look for cracks without spending more on testing than on the engine.
2. Used 4.0L out of my buddies recently written off 95XJ. I'm not sure what all I need to do to get this working with my 98. I know the head is slightly different... anything else, assuming my head is still good or can be valved?
3. Brand new 4.0L long block - $700; Almost certainly in perfect condition. The seller seems trustworthy and not like he's out to screw anyone. Says he's selling because he never got around to installing it, and crashed the Jeep it was going into.
4. v8 swap - $1500-$20,000
; Tonnes of work, way more expensive, could easily build myself a sickass stroker for the entry price of a v8 swap.
Um... 5... Build a stroker? This may be a bit beyond my capability right now. Don't have the space for it, but I didn't have the space for any of my other projects that got done either.
Thoughts and suggestions? I can probably get a few more months out of this motor, but it pains my soul to watch all those hipster jerks pass me in their Prius while I'm busy gearing down to third to make it up a slight incline.
Turned out it was no compression in the #6 cylinder. Stuck intake and exhaust valves. This was like, 7 years ago when I knew nothing. Replaced the head (again, I didn't know better) and it ran like a top, but I was definitely losing coolant, but there was no evidence on the ground or out the exhaust. Of course, the long short is that I had a hairline fracture in the #6 cylinder, which was small enough to go unnoticed without magnaflux, but large enough that when water temp/pressure got up to around 100, it starts slowly pushing coolant into the cylinder.
So I figured whatever. I'd just let it run it's course and do something about it when it became a bigger issue. Well, now it's a bigger issue. Started losing power on the highway on hot days, and sure enough, I'm low on coolant, and the #6 plug is rusty, and I'm losing oil pressure, etc. The loss of power I'm sure is being caused by stuck valves again (derp) caused of course by the constant flow of water into the cylinder. I'm guessing the rings and cylinder walls aren't too happy about the constant wash either.
I figure at this point, there's no point in pretending the head will still be good without at least a new set of valves. If I have to buy a short block, and some valves, I'm already into the price range of a decent low mileage 4.0L. If I'm seriously looking at spending $400ish on a used 4.0L, maybe I should just spring for a brand new LB (someone selling one locally for $700). And ya know, if I'm talking about taking out the old power plant, maybe this can be an excuse for a v8 swap....
*sigh*
So:
1. Used 4.0L - $300-$450; No real good way to know the condition without actually buying and installing. I can compression test and inspect stuff all day, but there's just no way to look for cracks without spending more on testing than on the engine.
2. Used 4.0L out of my buddies recently written off 95XJ. I'm not sure what all I need to do to get this working with my 98. I know the head is slightly different... anything else, assuming my head is still good or can be valved?
3. Brand new 4.0L long block - $700; Almost certainly in perfect condition. The seller seems trustworthy and not like he's out to screw anyone. Says he's selling because he never got around to installing it, and crashed the Jeep it was going into.
4. v8 swap - $1500-$20,000
; Tonnes of work, way more expensive, could easily build myself a sickass stroker for the entry price of a v8 swap.Um... 5... Build a stroker? This may be a bit beyond my capability right now. Don't have the space for it, but I didn't have the space for any of my other projects that got done either.
Thoughts and suggestions? I can probably get a few more months out of this motor, but it pains my soul to watch all those hipster jerks pass me in their Prius while I'm busy gearing down to third to make it up a slight incline.
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