Red, I'll be less subtle. I think he's shining you on.
I've replaced multiple head gaskets on engine exactly like yours, and listened to stories on several dozen, if not a hundred more. I know for sure I've done at least 10 of my own, the first several wrong until I finally got it RIGHT.
Old Colt (Charley), knows so much more about them than I do, it's scary. (Charley, you ever done anything but fool with Mitsu motors?? And if so, I don't care how old the Colt is, when did you have time to learn it). Frank is as thorough and informed about engines as you'll ever want to find. Unfortunately, his blow up ( <img src="/forums/images/graemlins/evil.gif" alt="" /> <img src="/forums/images/graemlins/evil.gif" alt="" /> <img src="/forums/images/graemlins/evil.gif" alt="" /> 's made me say that....), but I agree completely with his answers and advice.
Mitsu V6 engine bottom ends are very, very tough. If your oil pressure always read above 30 at most any normal cruising speed and the engine ran smoothly before, you can probably get away with just fixing the head gaskets AND WITHOUT FAIL, have the radiator taken out and to a professional radiator shop and flow tested and repaired as needed. DO NOT let anybody sell you a replacement radiator until you check back here.
"Fixing the head gasket" MUST include the following steps:
Remove the heads and have inspected by a GOOD automotive machine shop. You want them to inspect for cracks (pressure test and UV dye test) and measure warp and recommend repair and rebuild or replace. IF replace, check back here for a Clearwater aftermarket head source. Should be around $250-300 for a NEW head (better than the original) with all internal parts. I think it's pretty well established that this new head is the cheapest and best way to go, unless your machine shop is very inexpensive, and I probably wouldn't trust one that was...
Have the exhaust manifolds machined flat again at the machine shop, too. Should be 30-40bucks
Then you need a good head gasket kit. You want the head gasket set made by a company named Felpro, or stock Mitsu. I think I last paid something like 174bucks for the set.
Labor to remove the heads should be about 3-4 hours max. Prep to install and install labor should run 4-5 hours including testing.
Radiator service should be less than $150 unless they have to replace the core, in which case you can upgrade the radiator to more efficient new core and have it installed and all other leaks fixed for under $300.
You want all new belts and hoses, and I figure you'll spend around $150-250 on all that, plus under $40 worth of new oil and filters, and 10-15bucks worth of antifreeze and a new Mitsubishi radiator cap from the dealer.
You also want a new set of spark plugs, and I recommend NGK brand of plain vanilla spark plugs, no platinum, no iridium, no funky tip plain vanilla spark plugs, and new NGK spark plug wires. And a new air filter. Maybe another hundred total.
I'd be curious as to exactly WHY the engine must be completely replaced? What has he (the "mechanic") measured, or found broken, or found worn out? Has he already removed the head and measured the bores? That's one of the few things he can actually measure unless he already removed the entire engine and took it mostly apart.
If it is the whole engine, my best advice is to buy a running used engine with a guarantee that it is rebuildable when purchased, and rebuild that one. Done right, you end up with one as good as or better than new with the cheapest possible rebuild costs.
