Jump to content

MPG and Maintanence


crezman
 Share

Recommended Posts

Hello, someone just gave me a 1999.5 Pathfinder SE. She had it for 4-5 years and I'm pretty certain hasn't done much maintanence on it except maybe had the oil changed. It being such a great car and engine it has stood up to this abuse BUT it's MPG is low, just a little under 12.

 

After reading these board, I'm thinking with someone maintance, the MPGS might go up. I read on here someone did some TLC to his Pathy and gets 19mpg. So, I have a few questions:

 

#1-- What is a reasonable mpg on a well maintained Pathy? What can I except? I know it's not ever going to do 45mpg. But is 19mpg a good goal? 15? Or do some just run 12mpg unless you do quite a bit to it.

 

#2--Here's my list of things to have done under the current conditions. What else do you think I should add?

 

 

Spark Plugs Fuel Filter Distributor Cap Distributor Rotar Air Filter MAF Sensor Knock Sensor H2O Sensor

 

The car before her was owned by her x-husband for 10 years and he's a maintaince guy; so it's early life was pretty good. But the last 4-5 years I'm sure it has not gotten what it needs to run at it's best.

 

Even considering, the engine sounds damn good. It's got a great sound to it. It doesn't leak a damn thing underneath (the sun roof it another issue) and it always turns over.

 

After doing my research on these cars, I am super grateful to have such a solid vehicle and love driving it even though I live in the city and it is big for the city.

 

Thanks!

 

Chris

 

Link to comment
Share on other sites

Hey Chris! Depending on how you do it/what gearing and tires, 20mpg highway is about the best you can hope for, probably 15mpg around town...

I recommend doing as much as you can yourself, saving the $ for parts. Between help here, the free, downloadable Factory Service Manual in the Garage section, and general Youtube videos, there is a lot of basic stuff you can manage just fine.

 

If it was my R50, I would plug in an OBD2 reader to see what(if) fault codes are stored, check/replace the air filter and check/replace the plugs/wires/rotor and cap. Replacing the oil with the proper 5w30 oil might help as well. One huge boost is to have the front drive flanges replaced with manual hubs (you lose the shift on the fly capability, just have to stop and manually lock them) but it stops a lot of unnecessary drive train drag. Start with the codes first though, 12mpg is bad enough that something else is going on.

Brake drag is possible as well, but one thing at a time... ;)

 

B

Link to comment
Share on other sites

Ill reply more when home. But no need to replace the MAF and Knock sensor. Unless the maf is for sure sure 100% bad. Just clean it with MAF cleaner. If you have to replace it. The Maxima maf is the same and half the price. Knock sensor rarely go bad and is just a secondary code that pops with pretty much any other code that pops.

O2 sensors only if bad also. The rest is good normal maintenance procedure. Doing it yourself is the way to go. Make sure to get the link in the garage section the FSM.

 

Sent from my Moto X

Link to comment
Share on other sites

I would add to your list: new vacuum lines ( all of them including the one for the fuel pressure regulator ) 3/32" is cheap, maybe re-grease the wheel bearings, lube the slide pins for all four calipers with silicon (I just found out that a dragging brake makes for terrible 0-60mph times), the "skid-plate" saves a measurable amount at the end of a year in gas ( 1" of mercury lower on a vacuum gauge without the plate is going to add up after 18 000 miles)..... MAF cleaned, intake and throttle body cleaned.... maybe clean the fuel injectors.... that's about what I had on my list including everything you mentioned.

 

First thing I would do though is check the base timing if it feels at all sluggish.... correctly adjusting that brought my Pathfinder from the 10mpg area to 16-ish!! There is a link somewhere in here for that!

Edited by SpecialWarr
Link to comment
Share on other sites

You can safely bump it up a little higher if you want I am running mine around 20. No noise and it seems to get better mileage and have a bit more pep. Obviously it might fail emissions though.

Edited by adamzan
Link to comment
Share on other sites

Pretty much what everyone has said is correct. I'm getting about 12.5 right now. But I desperately need to get my exhaust manifolds replaced. They are cracked and mess with the O2's making the AFR wrong, and cause bad mpg, another thing is our cars react very well to a decent exhaust. Also, look at manual hubs, it unlocks the front wheels from the drive line, and while you loose the on the fly 4WD, (while they are disengaged) you gain around 2-3 mpg.

 

-Kyle

Link to comment
Share on other sites

  • 2 months later...

Ill reply more when home. But no need to replace the MAF and Knock sensor. Unless the maf is for sure sure 100% bad. Just clean it with MAF cleaner. If you have to replace it. The Maxima maf is the same and half the price. Knock sensor rarely go bad and is just a secondary code that pops with pretty much any other code that pops.

O2 sensors only if bad also. The rest is good normal maintenance procedure. Doing it yourself is the way to go. Make sure to get the link in the garage section the FSM.

 

Sent from my Moto X

 

WHAT is the " in the garage section the FSM?"

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...