Hey all!
Been quiet on here for years (literally) - for a main reason:
My truck's been running JUST fine, up until earlier this year.

2010, 240k miles, 2.3L I4.

Earlier this year, rear diff started to whine; it's life was up. To help determine whether it was worth it, I got a compression test on the engine. Despite the results, I went ahead and got a reman put in.

Now, though, it's time for the tranny to get replaced. And I'm at the point where I need to decide whether it's worth it or not.

The last dry-compression tests gave me cyls 1-3 in the lower 160's, all within a few points of each other. Cylinder 4, however, was in the lower 120's. (Exact numbers are not on-hand at the moment.) So the low one is FAR over that 20% limit I've read elsewhere.

I'm curious about that extra-low reading on the 4th. Is it a sign that days are numbered for the engine? Or potentially a bad reading?
The engine has given me NO issues in the last 11 years, save for:
1. Leaking head gasket about a year ago - leak was over the third spark-plug.
2. After head gasket replaced, started getting some knocking. Turned out to be a loose sparkplug. (The dealership I took it to to do the head gasket fucked up several other things, and I can NOT respect them. I honestly would not be surprised if they somehow are the ones that f*ked my rear diff, since I asked them to drain/replace the fluid.)

So, the engine has been solid; it still has great power in it. I'm just hesitant to drop $3k or so getting the transmission replaced only to lose the engine a couple months afterwards. :(

 

You would be getting a P0304 code(misfire #4) if the 120psi was a valid number, so disregard it

If you would like to keep the truck another 5 years, 60 months, and you think it will last that long without any other major repairs then do the monthly cost to drive it
If transmission work is $3,000 then it will cost $50/month to drive the truck 5 more years
Can't find much to drive for $50/month, lol

Low compression is 99% of the time an exhaust valve issue, and if the head gasket was redone then the valves would have been checked, so odd to have that issue which makes me think it was just a faulty test on #4

 

Okay, I needed that validation - at least that there would be *some* other clue that something was wrong with just one cylinder. Thanks.


Yeah, I took it a different route - I figure a new truck payment would be ~$500 a month at worst. A new tranny is 6 months of those payments. Would the truck be driveable for more than 6 months after a new transmission? Hell yeah. :D
I did some searching on here and other places about the transmission - because I was really upset that after 'only' 240k miles, something's starting to slip(*) and that it needs to be replaced. However, apparently it's normal for these to last between 200-250k miles. And since I sometimes often drive my truck hard and fast, I am quite pleased that it lasted on its upper range.
(*) - the transmission has always shifted on the harder side, there was a tech bulletin about a software upgrade back in the early 2010's which I had applied, but it never fixed the issue. Despite that, the transmission's always ran fine. Recently, though, under high torque, like WOT trying to get on an interstate, I've noticed a bad smell, like a friction surface is overheating. Despite this, no codes are being thrown.