recently took a trip to texas from michigan in the blazer and 13 mpg the whole trip. one of the o2 censor's went bad and changed that figuring it would fix it. Not exactly the case. The other problem is while the censor was bad, the truck always idled in a "cold start", again figuring the censor would take care of that as well it hasn't. Now I know blazer's aren't a prius on MPG, but come on, 13 on highway? The truck has the original engine with about 168,000 on it as well as the tranny.

 

Hello MuTaLiZeD,

I am not saying to do what I have done. Everybody's Blazer has its own ups and downs.
I am was fortunate to have money in my pocket to go all out in maintenance. It was getting
pretty much what yours was getting in gas mileage. I figured it was time for changes.
At about 145,00 miles my vehicle was running very poorly. It had original everything
on it. I changed all 4 oxygen sensors(AC Delco # AFS105) Changed Catalytic Converter
(WALKER #15827), Muffler(WALKER 36163). Full Tuneup, New Plugs(AC Delco-41-993)
New Distributor Cap (AC Delco-D328A), New Rotor (AC Delco-D465) New Spark Plug Wires
(AC Delco-746T) Fuel Filter(Ac Delco GF645) Transmission Filter(AC Delco TF333-Low Pan)
Changed all my fluids to Amsoil (engine Oil 0w 30) Transmission Fluid (Dexron 6). Complete
Engine Coolant Change(amsoil-ANT1G-EA) and Hoses. I now get 15mpg in the city and about 20-23 highway. I love my Blazer and have spent a bundle on it but it was better than buying another used vehicle and starting all over again. I keep my fingers crossed everyday and say a prayer when I start her up in the morning. She has been running nicely over the past few years. Good Luck+maintenance and who knows how long she will run.

 

replace you ect(engine coolant temp sensor) $15! That's what i was getting highway till I replaced that!

 

Hey MuTaLiZeD! You didn't mention an SES light,did you not have one? Is the tranny torque converter locking? Going into O/D? Hmmm...Just a guess but check TPS as well! My 97 was running at 1500rpm idle coming off a high speed run and then I noticed O/D was not working normally,R&R TPS and all is well again! My mpg even in winter remains 17-21,while in summer its a consistant 21-25. And yes I use my 4X4! All of marksoftball's recommendations are first rate as well! step66

 

AWESOME! I really appreciate all the ideas. When I bought the truck it was in some need of some TLC. So I replaced the usual wear and tear parts, including most of the cooling and a tune up. The censor was throwing a code, something like heater circuit malfunction bank 3 I believe. Not too sure on the transfer case, I do know every know and then when i slow down for a light, and it turns green when I start to accelerate again I will get a "clank" noise from the transfer case. I will check into the ideas, and get back to ya!