Hello! I own a 2007 Hummer H3. The vehicle has approximately 166,000 miles on it. As a general rule, I try to take meticulous care of my vehicle. Recently, I had a new radiator put into in earlier this year. Three weeks ago, during a trip from Little Rock to Memphis, I noticed that the engine was running hotter than normal (temperature gauge would be slightly under the 3/4 mark instead of the usual 1/2 mark - it was a sweltering day with temps over 104 degrees and A/C on full blast). Around this same time, I got a PO741 code saying that the torque converter selinoid clutch was stuff stuck in the off position. I live three minutes from work, but I knew I would have to address these issues. Interestingly enough the code went away for a week, but came back on a week ago. The vehicle didn’t really perform abnormally. I had a new thermostat put in this Friday. The mechanics test drove the the vehicle and burped the car. This was done in Heber Springs, AR because it was at a shop that my family trust. I also had new CV axels put on the vehicle as well. I made an appointment with a transmission shop in Little Rock to address the other code. I was planning on getting it sent on Wednesday. Presently it is Sunday. Going back to Friday afternoon, the car drove much better, but the same problem was present on the drive back. Yesterday, I went to go do a errand for my father, the car drove immaculately to the destination aside from the heating issue. On the drive back, however, I experienced problems. The first things that was noticeable was a loud noise that sounded like something was wrong with the exhaust manifold. The exhaust manifold is one year old. By the time I got back to Little Rock, the vehicle seemed to not have its usual power and was making a loud noises (it sounded like a diesel). I am genuinely scared that I have screwed up my vehicle and blown a head gasket or something, maybe it was going out all along. 

While I waited for the tow truck driver in my drive way. I checked the exhaust. There was NO WHITE SMOKE. I checked the oil stick, nothing looked out of the ordinary. I checked the transmission fluid, it looks normal (albeit time to be replaced). No smoke is coming from engine compartment… etc… etc… I probably never should have driven the errand, but hindsight is 20/20. I though these problems could wait a few more days until I got the vehicle sent off the full service garage. A really cool old grizzled tow truck driver said the loud noise was probable a donut gasket… I looked and looked for leaking fluid when it was being hoisted on the tow truck, but it was dry.

Any all advice is appreciated. If this is the worst case scenario, I don’t know how I am going to pay for all of this. I am hoping to get a great job in a few months that would easily give me serious income to address this, but I don’t have it just yet. Thank you for your time. I hope my rambling story makes sense.