bgibb

Quick question here...I just had the head rebuilt on my '95 runner (gasket, valves, t belt, WP). The engine is much more peppy (I know that sounds paradoxical from a 3.slow but comparativly it is), but I'm noticing a decrease in gas mileage and its now burning oil. I was warned about it burning oil due to higer compression, but is there anything that would cause a decline in gas mileage? It's dropped about 20 miles per tank (just over 1 MPG). Is there any thing that could be messed up I can check that could have been adjusted when they did the work on it (i.e MAF, TPS, ECT)? Any solution to it burning oil as well? The engine has only 120,000 miles...

Thanks...

Silver_Truck

1 mpg isn't much of a diff, there could be alot of stuff contributing to that, although its weird that after rebuilding it your mileage did drop, mine went up roughly 5 mpg. burning oil could be a leaking seal (or one that was not put in). Did you do the work yourself? You may be burning a little oil as the seals set so I'd just watch for another week or so and see. there shouldn't have been any electronic work done (tps, AFM etc.) I didn't touch that stuff on mine because there was no need for it.

bgibb

I had the work done at a shop...would hot weather contribute to poor performance? I was told the oil burning could be from older piston rings and with the higher compression it causes the engine to burn a little...

And I guess I was expecting an increase of 3 or 4 mpg after the work so a 1 mpg drop feels like 5 to me...

Bumpin' Yota

you keep mentioning a higher compression....did they put aftermarket pistons in, deck the block or shave the heads? Unless you had nonsealing valves the work they did shouldnt have done anything to compression...

bgibb

Well...they did a complete valve job because three were not seating properly anymore and they told me that would up my compression...and they did machine the heads...

Silver_Truck

That shouldn't increase compression, I had a 3 angle valve job done on mine when I rebuilt it and I don't believe that the compression has increased (it shouldn't), I'd find out what kind of machining they did, you can't shave the heads on our motor that much. The only way a valve job will icnrease your compression is if one was burnt or stuck open...I'd give em a call and find out exactly what they did.

bgibb

I called the mechanic that did the work but he wanst coming in until later today...so i will post exactly what was done soon...but one other thought...anyone more ideas? I leave on a trip first of the week and want to work on it this weekend if we can come up with anything...

thanks again...

94x4

The mileage and oil burning could be attributable to the valve seals needing to "seat" themselves, as is often the case after having the head(s) rebuilt, and may have some bearing on the increased compression, though doubtful.

I'll side with Silver_Truck and advise you to give them a call to find out what's up.

ROMAD

I bet these two are related - every time I get some more pep out of my 3.0 the MPG takes a hit for a tank or two until I learn to get my right foot out of it

dragon564

You gotta tell me how you learn that.....I have tried and tried to get my right foot out of it just can't seem to get it down though....and that damn MP3 player really sucks the gas down

ROMAD

Yup...AC/DC, Motley-Crue, Metallica and several others are just as guilty for the oil shortage as anything else the way I see it...

Thank god I turned 16 in an age of $0.89 gas and affordable F-body's'

bgibb

Well, the mechanic that did the work on it is out of town until Monday, so I will find out then. If anyone else has more advice I would appreciate it and for those wo replied, please read my post on Monday.

Thanks

bgibb

Well...mechanic did say that one valve was burnt (#6) and thats why the valve job was necessary, the other valves weren't as bad but we did them all anyway...but I think 94x4 was right cause the oil burning has decreased...I guess the only other contributors could be the d@*# fan clutch that sucks power in hot weather and my lead soled shoes I occasionally wear...

Maybe I do just need to follow NOMAD's advice and throw out all my hard rock and see if that helps!

Thanks for all the tips...

94x4

"I was right, swear I'm right, swear I knew it all along and I'm flawed, but I'm cleaning up so well, I'm seeing in me now the things you swore you saw yourself, my hope (that we will all one day be right) dangles from a string (thread) like slow spinning redemption..." (dashboard confessional)

Alright, enough with the self effacing, egomaniacal hoopla, I'm glad to hear that you got your ride sorted out, especially after dumping the funds into it, but you did'nt say whether or not they fixed it for free...,??