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General Forums => The Mess Hall => Topic started by: elpablodiablo23 on September 02, 2010, 06:49:49 PM
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Hey everyone, I just got done rebuilding my 2.5 cyl. in my 93. Its running smoothly, but getting horrible gas mileage. The story is, my last engine dropped a valve and destroyed the head and cracked the sleeve in the #4. I picked up a 95 2.5 cyl for dirt cheap, and used that block/head, but most everything else from my 93. The only difference is, the 95's block was already .050 over, so after a trip to the machine shop, it left .060 over, which is how i rebuilt it. it was a complete overhual. I've got about 300 miles on it now, but its only getting about 12-13 mpg, which is horrible. my last engine, not too long before it dropped the valve, was getting 13-15. I was hoping to getting near 20 like my old motor USED to get. Could it be the .060 bore?
what are your thoughts? As far as i can tell, everything is re-assembled correctly. I'm asking for your advice on what to triple-check.
other info: I'm using a 180 thermostat instead of a 195. is that causing bad efficiency? the engine isn't heating up unless im on the street in traffic. at highway speeds and even around town it won't heat up. I know these engines run pretty cool...its engaging my electric fan at about the right temp, so i have no reason to believe its a bad guage.
Thanks for any advice or reccomendations
Paul
everything is STOCK, right down to the airbox. so I'm not sure what else beside the
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new engines will do that.
My dad's salesmen vehicles he used to buy new. and he said it they got best mpg's at or around 100 000km's range. when there new there not as loose "from wear" and they burn a bit more fuel. you will have to brake it in and it will get better as the miles role on!!
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Hey everyone, I just got done rebuilding my 2.5 cyl. in my 93. Its running smoothly, but getting horrible gas mileage. The story is, my last engine dropped a valve and destroyed the head and cracked the sleeve in the #4. I picked up a 95 2.5 cyl for dirt cheap, and used that block/head, but most everything else from my 93. The only difference is, the 95's block was already .050 over, so after a trip to the machine shop, it left .060 over, which is how i rebuilt it. it was a complete overhual. I've got about 300 miles on it now, but its only getting about 12-13 mpg, which is horrible. my last engine, not too long before it dropped the valve, was getting 13-15. I was hoping to getting near 20 like my old motor USED to get. Could it be the .060 bore?
what are your thoughts? As far as i can tell, everything is re-assembled correctly. I'm asking for your advice on what to triple-check.
other info: I'm using a 180 thermostat instead of a 195. is that causing bad efficiency? the engine isn't heating up unless im on the street in traffic. at highway speeds and even around town it won't heat up. I know these engines run pretty cool...its engaging my electric fan at about the right temp, so i have no reason to believe its a bad guage.
Thanks for any advice or reccomendations
Paul
everything is STOCK, right down to the airbox. so I'm not sure what else beside the
with a 180 t/stat should heat up to 180, if it doesn't change it as it means it is getting stuck on open. That will cause a lower mpg and since we're talking 1 to 2 mpg that sounds right.
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My mileage dropped just about the same amount with a 180 instead of a 195 thermostat (94 YJ)
Plus it runs way too rich, the 2.5 is perfectly happy at 200 to 205 near as I can tell. Mine runs nice with the 195 stat.
Dave
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My mileage dropped just about the same amount with a 180 instead of a 195 thermostat (94 YJ)
Plus it runs way too rich, the 2.5 is perfectly happy at 200 to 205 near as I can tell. Mine runs nice with the 195 stat.
Dave
MPFI's like running a bit warm.
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Change the thermostat to a 195 degree one does make a difference in milage
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Untill your rings fully seat your mpg will be lower then normal, takes upto 4500 miles or so for the rings to completely seat.
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Untill your rings fully seat your mpg will be lower then normal, takes upto 4500 miles or so for the rings to completely seat.
+1 on engine brake in!!
not to mention your saying horrible fuel miles and were talking between 0-5 mpg's diff. get the warmer t-stat and other then that the engine needs break in time!!!! plus outside temp and humidity and winds can change it drastically on a square jeep!!
don't forget to your computer will take a while to relearn!! and if it's carb you may need to do some tuning to get your miles back now that the engine is fresh.
but I wouldn't sweat it till it's done some more brake in time!! running a little rich for brake in won't hurt anyway.
another thing that wouldn't hurt if you are fuel injected to pick up a new o2 sensor especially since you had a valve drop and prob some crap when out the exhaust!!
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If you can run the Joe gibbs break in oil. It really help lap the cam in... Has extra zinc and sulfur...
NO synthetic! at least for the first 10K I switched too quick and the rings lost seat,
ran regular non detergent 30 wt for a couple K miles and they came back in...
Dave
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Hey thanks for all the advice! My tranny just blew though...600 miles in...it never ends....ha...
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Hey thanks for all the advice! My tranny just blew though...600 miles in...it never ends....ha...
I feel your pain :brick:
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Hey thanks for all the advice! My tranny just blew though...600 miles in...it never ends....ha...
could have been another reason why poor fuel econo