Engine running cold and bad gas mileage
#1
Engine running cold and bad gas mileage
Another thing Ive noticed with my 93 Z28 is that the car doesnt seem to ever go over 150-160 degrees. Idle, city driving, highway driving.. its all the same after the car gets warmed up. Ive done some research and I should definitely be over that by what.. 30, 40, 50 degrees? I dropped 20 bucks in her once I got her registered and ran about 80 miles. With gas being 2.40 or so, I did the math and it averaged out to about 10 mpg. My first instinct was that the thermostat was stuck open, completely removed, or a previous owner put a 160 degree thermostat in it.. but I havent had a chance to check yet. Im going to check in the morning once I get home from work(nightshift).
Would running at 150-160 degrees on a (presumably)stock LT1 really cause my gas mileage to take that big of a drop? Or do you guys think there might be something else at play?
I also noticed in the fuse box that the fuse controlling the fan which is supposed to be a 10 watt fuse.. is actually a 30 watt fuse. Can the fan affect temperature that much? When I brought the car over for my dad to see.. we noticed that fuse and he was like, "Go turn it on." So I did, and let it idle for a few minutes. He had the fan fuse in his hands when I turned it on. About 3-5 minutes into the car running at idle, he put the fuse back in place and the fan turned on. Then he removed it and obviously it turned off.. but should the fan have been running there at idle like that? I thought they didnt engage until the car got up to temp because engines are more efficient at higher temperatures.. or am I mistaken?
Thanks yall.
Would running at 150-160 degrees on a (presumably)stock LT1 really cause my gas mileage to take that big of a drop? Or do you guys think there might be something else at play?
I also noticed in the fuse box that the fuse controlling the fan which is supposed to be a 10 watt fuse.. is actually a 30 watt fuse. Can the fan affect temperature that much? When I brought the car over for my dad to see.. we noticed that fuse and he was like, "Go turn it on." So I did, and let it idle for a few minutes. He had the fan fuse in his hands when I turned it on. About 3-5 minutes into the car running at idle, he put the fuse back in place and the fan turned on. Then he removed it and obviously it turned off.. but should the fan have been running there at idle like that? I thought they didnt engage until the car got up to temp because engines are more efficient at higher temperatures.. or am I mistaken?
Thanks yall.
Last edited by ztwentyate; 04-06-2015 at 11:50 PM.
#2
flash for trouble codes. look at 23 here 4th Gen LT1 F-Body Tech Aids also look at 12 while your there
#4
Ok i just flashed the codes. Im getting 26, 32, 61, and 64.
26 - Evaporative emissions canister purge solenoid circuit
32 - EGR recirculation
61 - A/C system performance
64 - Bank 2 (right) O2 sensor, lean
Ok so Im reading the service manual entries on these.. 26 seems a little over my head, but 32 I can sort of wrap my head around. It says on 32, DTC 32 can be caused by a leaking exhaust system and any time Ive had the hood open I can smell exhaust. Looks like 61 relates to my other thread and based on the last response from a guy, I might be able to fix that one myself. After reading 64.. it almost seems like maybe 26,32, and 64 are all related perhaps by some exhaust leak? Im just guessing here and could be wrong but based on the service manual articles.. it seems like theres some corrolation between these.
26 - Evaporative emissions canister purge solenoid circuit
32 - EGR recirculation
61 - A/C system performance
64 - Bank 2 (right) O2 sensor, lean
Ok so Im reading the service manual entries on these.. 26 seems a little over my head, but 32 I can sort of wrap my head around. It says on 32, DTC 32 can be caused by a leaking exhaust system and any time Ive had the hood open I can smell exhaust. Looks like 61 relates to my other thread and based on the last response from a guy, I might be able to fix that one myself. After reading 64.. it almost seems like maybe 26,32, and 64 are all related perhaps by some exhaust leak? Im just guessing here and could be wrong but based on the service manual articles.. it seems like theres some corrolation between these.
Last edited by ztwentyate; 04-07-2015 at 03:19 PM.
#5
exhaust leak can cause 02 sensor to give false readings. 02 sensor may be fouled. evap can cause lean or rich condition. test gas cap, look over evap hose/pipe for leaks. ac fail can cause fan to come on all the time. i would say three issues.
#7
Hmm alright well thanks so much for the explanations guys. Ive put gas in it a few times now and regardless of the level of fuel in the tank.. It seems like alot of pressure is built up that when I remove the gas cap I get a loud "whoosh" (lol best I can explain it). I'm definitely going to fix what I can and I'll get back and let you know what I find. You guys are f****** awesome
Last edited by ztwentyate; 04-08-2015 at 04:29 PM.
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