How's it going Hummer Forums?

I wanna keep this short and sweet. I'm 17, have a 2007 Hummer H3 and I'm here to ask for some help and general guidance.
As stated before I drive a 2007 Hummer H3 with the standard I5 engine in it. I have done some light modifications on it, those being a roof rack and a cheap but overall nice brush guard (bull bar whatever you wanna call it) for the front where I have a Procomp 30in lightbar. It has about 120k miles on it as of this post and has gotten into a couple of minor accidents but runs great. The only problem that I can tell is that there seems to be a leak in the coolant system somewhere, I haven't quite pinpointed where it is but unless hummers suck the radiator and the overflow dry within a couple of days, a leak is what is to be presumed. The tires are new with them being only a couple of months old except for the spare (still the same tire as the new ones) with a new Kenwood radio as well. The only major repair it has had is having the right rear axle entirely replaced. Everything else on the vehicle is stock.

This thing is my pride and joy and I love everything about it but I sure would love to put some more into it, I just don't really know where to start. I use it for casually driving as well as some offroading/ mudding when I can.

If anyone would like to give me some pointers on what some good investments I should put into it that would be greatly appreciated. The most recent ideas that come to mind after some research are a cold air intake and hopefully straight piping it (I would love to lift it but money isn't the best at 17). Anything at all really helps whether it be telling me what some good parts are to even quality of life addons.

Much Appreciated

 

I would also like to add that my driver's seat has a problem that I have seen to be somewhat rampant where the seat will move forward but it will not move back. I have yet to see a tried and true fix to this. Any advice on that would be greatly appreciated.

 

Welcome to HF.

My best suggestion is that you spend some time here reading through threads on topics your SEARCH. Reading means read them, do NOT dig up old posts and tack on the end like you have to demonstrate you found it.

I will work backwards on your questions. Lifting it is NOT an option as every true "lift kit" for H3/H3Ts are no longer made, not in stock and gone. I suggest you learn to drive what you have in off road settings/obstacles where you will find tires, undercarriage protection and rock rails are more important than some lift kit. Look into adjusting the T Bars to level the front to a max of 23.5" fender lip to hub center.

Straight piping? LOUD is NOT fast or powerful and in most states you can get a ticket for that. Look into a good CAT Back system, many are still available. Straight pipe or CAT Back are not going make any power, just sound/tone.

An intake is a good inexpensive way to pick up a small performance boost to compliment your exhaust mods. I suggest a closed system, one that keeps the Air Filter in the OEM or aftermarket box to avoid water, dirt, mud, snow, ice from choking your Air Filter element. A good aftermarket replacement Air Filter in the OEM box can outflow an exposed Cone shaped filter and has more filter media for better filtration. I know a guy in that business.

Look into a PCM tune (NOT a chip) and an Efan conversion. A PCM Tune can take advantage of any intake and exhaust mod and grow your truck some *****. Next to an Intake, probably the best bang for the buck improvement. The Efan conversion does not make any power, but it does free up some to improve performance and MPG.

H3s are known for leaking Radiators. A pin hole leak or tiny crack may be what you have. Might never leak onto the ground until it gets worse. You should be able to smell coolant after a drive and sticking your nose under the hood. Make sure to check your Oil, Trans Fluid and Coolant quality to make sure you do not have a leak inside the system. Coolant in the wrong place can kill a Trans in short order.

Before you do any performance mods, unless you KNOW when the Trans (& filter), T Case, Front and Rear Diff fluids have last been changed, do them all.

Enjoy.

 

Head to your local AutoZone, oriellys, advanced, etc.. take your pick. Inquire about renting a radiator pressur test kit? Head to UTube and watch a video on how to best test your system. That is way more important then any other item for your H3 lol! No fluid in the rad means a crack in the block or head.

After you get that sorted out head to Utube and look up a video about lifting your Hummer H3. There is actually a guy does a video on custom stuff to make a minor lift.

 

I genuinely thank you for your insight. The radiator part helps a lot (as much as I'd hate to admit that it has a problem). It would probably be in my best interests to maybe rent a radiator pressure test kit as another user commented. As for the whole straight piping thing, I know that fast doesn't equal loud I may be young and naive but I am self aware in the fact that i'm an annoying 17 year old. Regardless I appreciate the help but by the time I get a fraction of the money to do anything I want with this i.ll probably be near my 30s by my estimate. Gracias mi amigo

 

The YouTube Diff Drop spacers are a for chit idea, tried years ago by many, and will get you poor results over time.