I purchased an H3 hummer in wi just over a year ago. I love it for how its fun to drive and looks sharp. I moved to sc about 8 months ago and since the cars down here rarely rust I have been turned away from two oil change places because they couldn't get a rusted on bolt off. I took it to a dealership and they put some wd40 on it and off it came right away. I was also told I would have a hard time selling it to any dealership here because of the rust. I bought it for 15k with 62k miles on it and a newly replaced engine. The engine still has about 10k miles left on the warranty. More recently I have taken it to a different dealership that could not diagnose a rough idle seconds after a cold start. that issue goes away after i engage drive and give it some gas) I had planned on keeping this car for a long time and in the short just over year i have owned it i put a lot of money into cosmetics... i put two new front and rear bumpers, new tow hooks, new brush guard and had some small rust spots touched up inside the door where the kick panel rubs. the car looks pristine except underside is rusted (like all northern cars do that are 12 years old) I also bought a tire cover, new tires, and replaced the factory radio with a navigation/bluetooth radio...it now has 82,000 on it and i feel like i can't sell it to anyone down here without "ripping them off" or a dealership offering me next to nothing for it. Im not sure if its worth it to keep it either... after all i did throw a couple extra grand into it and do like driving it im just concerned about my issues and how its been hard to get serviced in the south...nice / helpful opinions appreciated

 

Change your own oil and do your own repairs?
Fix the surface rust underneath or leave it and dive/enjoy your rig for years?
Why did you "put a lot of money into cosmetics" if you wanted to get rid of it?

 

i don't want to sell it and didn't plan to until its become more of a headache than an enjoyable machine...also i don't know how to fix things myself and i don't want to either not even changing the oil do i want to do myself...

 

A 12 year old vehicle and unable to wrench yourself, you will need a fat wallet to keep it reliable. Maybe it is not a good fit for your, unless you do not mind deflating your fat wallet periodically.

 

The underneath of my H3 was rusty and I had no trouble selling it. Those oil change places sound like high school dummies if they can't get a rusted bolt off. You need to find a better mechanic. You could always put an undercoat on the underneath and sand the rust off yourself

 

The advantage of getting under your rig and doing oil changes is to inspect for rust and other problems while under the truck.

When I do my oil changes I have a 1 inch paint brush and a spray can of penetrating or some type of spray oil to hit the spots that have oxidation.

If you wont do your own see if you can find a local mechanic that will go the extra few bucks to treat your baby right for you...

 

Most normal maintenance is bolt off, bolt on type stuff. You don't have to be a mechanic to do it. Do the simple stuff yourself and take your truck to a mechanic for anything more complicated. When I have the time working on my trucks is therapeutic. Kind of like driving my tractor, I need my tractor therapy.

 

Yes, crawl under it with wire brush and something to spray(Fluid film, ATF, oil), as long the lubricant is not destroying rubber.
Brush off flakes, spray. Easiest thing to to.
If possible trace all drain holes make sure they are not blocked, spray inside all frame holes something.
Open up doors, check for rust, spray inside there also and make sure drain holes are not blocked.
Pick up carpet, look for rust, brush, vacuum, spray and pray.
Unbolt/clean/bolt ground connectors before spraying over them if possible.
Drop all shields/protectors, same story.
Fuel tank clamps(metal things that go around it) get rusty and you can't see em, drop shield, clean everything up.
Remove front/rear bumpers, clean & spray anything/everything.

Of course, grounding off rust, then priming->painting would be nice thing to do too, I do it in only where paint has come off.
Plastic tend to scratch off paint and metal starts to rust too, remove all plastic everywhere and inspect damage.

Connectors will fail because of moisture and oxidation with time, check your heater motor-resistor connectors, clean them and put back, will pay off in long run.
As metals oxidize, cable/connection point that current passes trough gets thinner and thinner, eventually it will heat up and burn out(and not triggering fuse), in demanding areas.

good luck, have fun and have 2nd car for driving while you fix your Hummer