No sense in staying on the board, though it is interesting. Just got the news back from the mechanic... the CO2 test failed miserably, so it probably needs head gasket, heads, or a new engine... they only offered the latter at about $6000 for a used rebuilt.
The CO2 test vial went straight from the dark blue to the light green in a matter of minutes. It didn't run that long overheated... and my ole lady said it only happened that one night (yesterday). They figure its because of the high mileage (162,000). Temp gauge went from cold to mid-point in less than 5 minutes, as well. They were pretty adamant that the block was compromised. Here's exactly what they put on the invoice (only charged me $36 for the test).
"Upon starting of engine and driving into the shop, the operating temperature raised towards normal in a very short period of time. Performed 'Chemical Block Test' procedure... cooling system failed test indicating exhaust gasses are present in the cooling system which suggests either cylinder head(s) and/or cylinder head gaskets are compromised allowing abnormal levels of pressure to develop in system thus causing overheating concern. Would need to remove cylinder heads for further inspections, however, due to accumulated mileage, do not recommend repair, rather a replacement and/or remanufactured motor."
Yep, that is definitely a tell tail sign of not good things.
We just went through this with my daughters 94 Cherokee. But it was so bad that just cranking over the engine with the starter produced visible bubbles in the coolant.
It cost us around $1500 to do a junk yard engine swap (DIY). But I pretty much replaced everything on it except bearings, rings, and head gaskets before I put it in. Kinda like a long block swap + a new timing chain.
At this point you need to decide if it is worth it to put the $ into it, or buy a new/used rig.
For us it went like this...
For $1500-$2000 we could buy a comparable used rig, but you never know what you are getting.
So we did the math... A used rig payment would be about $100 a month(+ full coverage insurance till it was paid off).
$1500-$2000 / $100 a month = 15-20 months. So if it lasts 15-20 months it has paid for it's self, and saved us the extra on the insurance.
As it turned out we put $1500 into it, so we were on the low side of our estimate. We also know the rig and its history, which also gave us piece of mind.
Yeah, financially I'm stuck. We can roll the existing loan (about 7100) into a new car and end up paying 450/mth. The new car has the lifetime warranty ('17 jeep patriot 4x4) unlimited miles and years, so repairs wouldn't be an issue so long as we own the car. But still, that's 150 more per mth than I am paying now on the Nitro. all sucks. Don't want to go used this time around, want a vehicle that will be reliable through my wife's retirement. They get ya coming and going. Other thing is to go with this loan now, and refinance down the road (a year or so).