Compression: engine rebuild or not?

[Super77]

Had the 62 in for some deferred maintenance. I do most of my own wrenching, but peace of mind before overloading season, I took in to a very reputable Land Cruiser-only shop in my area (they're known on 'Mud). Compression test yielded 185-190 in 5 of 6 holes, and 135 in #2. Leak down test suggests rings. Fouled plug suggests I'm burning some oil there.

My gut tells me to leave it be. I drive the truck ~2500 miles annually, it's a third vehicle, mostly a weekend toy or materials hauler. Engine runs a bit rougher than it could, but smoother than I expect for an unmolested original 208K mile engine. No other engine issues to note. My only hesitation would be if this could lead to a sudden failure, but I don't think worn rings do that.

Check my thinking, 'Mud?

I got a ballpark of $7K for a proper rebuild of the 3FE, but that just gets me back to a very nice, underpowered, gas-swilling lump. Any other options to consider? And before anyone says "Vortec swap," (which admittedly would be awesome) remember my ROI case above. .

 

[OSS]

My advice is don't ever check the compression unless the engine is obviously not running well. Otherwise you're left in this predicament. 135psi isn't low, but all the others near 190 psi seem unusually high, especially for all the miles on it.

If it was my 3rd vehicle and I wasn't gung ho on trying to make it perfect and I didn't want to blow $7K on a rebuild for a car I rarely drove anyway — I'd leave it as is.

 

[LCnAZ]

Had the 62 in for some deferred maintenance. I do most of my own wrenching, but peace of mind before overloading season, I took in to a very reputable Land Cruiser-only shop in my area (they're known on 'Mud). Compression test yielded 185-190 in 5 of 6 holes, and 135 in #2. Leak down test suggests rings. Fouled plug suggests I'm burning some oil there.

My gut tells me to leave it be. I drive the truck ~2500 miles annually, it's a third vehicle, mostly a weekend toy or materials hauler. Engine runs a bit rougher than it could, but smoother than I expect for an unmolested original 208K mile engine. No other engine issues to note. My only hesitation would be if this could lead to a sudden failure, but I don't think worn rings do that.

Check my thinking, 'Mud?

I got a ballpark of $7K for a proper rebuild of the 2F, but that just gets me back to a very nice, underpowered, gas-swilling lump. Any other options to consider? And before anyone says "Vortec swap," (which admittedly would be awesome) remember my ROI case above. .

What were your leak down percentages? Was the tech able to hear the leak anywhere from any of the cylinders? If so, where?

 

[Super77]

What were your leak down percentages? Was the tech able to hear the leak anywhere from any of the cylinders? If so, where?

Dunno. We didn’t get into that level of detail. What’s the significance of knowing that information?

 

[Super77]

135psi isn't low, but all the others near 190 psi seem unusually high, especially for all the miles on it.

Yeah, I was surprised at that too. 180/135/190/185/190/185 (hot). So one out of six is at 75% of normal compression and probably has been for the whole time I have owned the truck. I’m replacing the plugs, wires, and distributor cap to at least get a hot spark, and rockers are all correctly lash-adjusted.

 

[LCnAZ]

Yeah, I was surprised at that too. 180/135/190/185/190/185 (hot). So one out of six is at 75% of normal compression and probably has been for the whole time I have owned the truck. I’m replacing the plugs, wires, and distributor cap to at least get a hot spark, and rockers are all correctly lash-adjusted.

The rest of the gallery can pitch in their two bits worth, but as I understand it, the compression test does give us some some idea on power, but virtually nothing with regards to data that is useful for analysis. A perfect, new engine would theoretically have 0% leak down in each cylinder. As our engines get older (or race car engines) the cylinders don't remain air tight. Your compression numbers are a little better than one might expect for the age. The exception is #2, of course.

A leak down provides the percentage of leakage from each cylinder, PLUS it provides information of where it is leaking from since the leak can generally be heard. Depending on where it's heard (exhaust, oil filler, etc) tells us where it's getting out of the cylinder. I'm about to have a leak down done on mine just before and after adjusting valves. My challenge is finding a tech that is experienced at this. I am hoping that any leaks I have are due to the valves not being adjusted for way too long. In your case, a tech well-experienced with this can likely tell you a lot about your engine...especially #2.

I don't subscribe to the see nor hear any "evil." Ignorance is bliss...and very possibly more expensive. Negligence certainly is more expensive.

 

[NeverGiveUpYota]

I’ll put my two cents in since I recently stepped into this rabbit hole.
Let the truck be. If it’s a once in a while joy ride then keep the smile on your face when you get behind the wheel. I agree w/ @OSS, don’t test it anymore. As well as if my opinion matters, the higher number would trouble me more. But really, let it go. 7k isn’t chump change....
Regarding a leak down, @LCnAZ, I was able to run a one... took some fiddling before I understood what I was doing but it doesn’t need to be done by an experienced tech. If you have an air compressor, you can do it. I, sure as hell, are not an experienced tech.

 

[Devils Paw 80]

2F in a 62? Should have kept the 3FE.

I would run it as is.

 

[LCnAZ]

I’ll put my two cents in since I recently stepped into this rabbit hole.
Let the truck be. If it’s a once in a while joy ride then keep the smile on your face when you get behind the wheel. I agree w/ @OSS, don’t test it anymore. As well as if my opinion matters, the higher number would trouble me more. But really, let it go. 7k isn’t chump change....
Regarding a leak down, @LCnAZ, I was able to run a one... took some fiddling before I understood what I was doing but it doesn’t need to be done by an experienced tech. If you have an air compressor, you can do it. I, sure as hell, are not an experienced tech.

@NeverGiveUpYota, I'm sure you did a fine job. Thank you for your encouragement. Heaven knows that's how we ride in this forum. For my peace of mind with this task, I'd rather rely on someone I know who has quite a bit of experience with it. I've learned in life that there is no substitute for experience...and how much valuable nuance I can miss without it.

@Super77 ...only you can decide where you find peace of mind with regards to your vehicle.

 

[Super77]

2F in a 62? Should have kept the 3FE.

Duh.

 

[cruisermatt]

Leave it alone, drive enjoy. You can do a really nice Vortec swap for less then $7K

 

[LCnAZ]

What? Me worry?

I don't think we're giving the OP the courtesy to encourage him that there may be reasonable alternatives to an expensive rebuild. You can't find those without...knowledge. Everybody seems to be at the extremes with their advice; do nothing, rebuild, or swap. When Super77 says his instinct is to "leave it be," I think he means not jump into something big like a rebuild, not do nothing.

Analyze. Do what is reasonable to you. It may turn out that doing nothing is reasonable at this stage. Or you may find something not so big on which you can intervene that will save you $$$...or cost you $$$ if neglected. That's my experience after 30 years with mine.