We got our blazer on the road for the winter, to drive 150km daily (75km both ways) and right away I noticed a couple of problems:

-There is a squeaking from the back end whenever I go over bumpy roads

-The trip meter is recording low. what I know is a 75km trip is being recorded as 70km.

-parking brake pedal will not lock in place.

-I seem to be filling up more often. Maybe it's because I'm used to the little "Road fleas" I use in the summer, and their capability to get 300km with half a tank, but this blazer seems to be using a third of a tank for a 150km trip...

The blazer was not used over the summer, because it got a bunch of front-end chassis work and regular maintenence done on it. I changed out the filters and fluids last year, But i have yet to change out the sparkplugs.

Are there any other things I should go over to improve milage?

What would be wrong with the trip meter? I don't remember it doing this before. The only electrical work i did that affected the whole vehicle was changing out the battery this fall, But I can't see that affecting the circuits there...

 

If you would put your vehicle info in your signature, we would not have to ask "What are you driving?"
The squeak could be from any suspension or body mount bushing. I have the same issue with mine and have used silicone spray with no luck.
The parking brake problem is most likely a broken ratchet mechanism that will need to be replaced.
For the tripometer issue, are you running standard size wheels and tires and did you previously measure the trip distance yourself or go by a map reading?
For better mileage, I would change the spark plugs, wires, and distributor cap and rotor.

 

The vehicle in question is a bone-stock 4-Door LS w/ a automatic 4.3 V6


I turned the 4wd on and off a couple of times while pulling out this morning, and I appear to not have used so much gas this time. Maybe the 4WD system is not disengaging properly?

The other cars I used all record the distance as 75km.

Only change in the wheels was brand new winter tires (I should check the number - They do seem about a couple inches wider in diameter)

 

Any particular year?

If the information was in your signature we wouldn't have to ask.

 

Blazer is a '98

The tires are 235's

(Added my specs to the signiture by popular demand :P)

 

What is the tire size as indicated on your door sticker?

235's came in both 70 series and 75 series tires which is a rough difference of 1" OD (235/70R15 = 28" OD 235/75R15 = 29" OD) That 1" difference represents a 3.5% difference in distance traveled. So if your door sticker states 235/70R15 and you have 235/75R15 tires, you can expect that 75km trip to be read as roughly 72.3km. I'd take a closer look at your tires.

 

Okay, the problem is the tires. they are 235/75's, not 70's like the door sticker asks for. I guess i'll put up with them and make sure the right tires are put on next time.

Just curious, is there any way to adjust the speedo?

 

That would have to be done via a reprogramming in the Powertrain Control Module (PCM).

 

The dealer can change the tire size with the Tech2. Some other high dollar scan tools can do it as well. Most tire shops have the scan tools that are capable of it, but are very leery of doing this modification. Typically it is due to a lack of understanding.