8.5 MPG on a Stock 5.9 Gasser. Possible to improve MPG?
#21
10-15-2023 | 08:51 PM
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Joined: Sep 2023
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From: Santa Barbara, CA
My speedometer reads high too. I think someone had taller tires and adjusted the sending unit. My temperature gauge was reading where yours is when I tore it down for a major tune up. It never warmed up and had a 195 unit in it. The timing chain had enough slop it never warmed up. It warms up fast now and the one time I had the heater going it was much warmer than last winter.
You can check your chain for slop. It's fairly labor intensive but it will tell you if you need a new chain set. This is easier if you remove the fan shroud. Rotate the engine by hand until the timing mark on the balancer is at TDC. Compression or exhaust, it makes no difference. Pull the distributor cap and mark the location of the rotors with soap stone, paint marker or anything EXCEPT a pencil. The graphite in a pencil will cause shorts and a misfire. Once you have everything set, rote the engine backwards by hand. When the rotor starts to move, stop. Measure how far it went3 or 4 degrees is no big deal.10 degrees though, your chain is worn.
Your temperature gauge should read closer to the center mark around 200 degrees. Timing being off will cause this. I had a '94 Ram 1500 with the V-6 and it went from 15 mpg to 23 on the highway and heat would cook you after a new timing set.
You can check your chain for slop. It's fairly labor intensive but it will tell you if you need a new chain set. This is easier if you remove the fan shroud. Rotate the engine by hand until the timing mark on the balancer is at TDC. Compression or exhaust, it makes no difference. Pull the distributor cap and mark the location of the rotors with soap stone, paint marker or anything EXCEPT a pencil. The graphite in a pencil will cause shorts and a misfire. Once you have everything set, rote the engine backwards by hand. When the rotor starts to move, stop. Measure how far it went3 or 4 degrees is no big deal.10 degrees though, your chain is worn.
Your temperature gauge should read closer to the center mark around 200 degrees. Timing being off will cause this. I had a '94 Ram 1500 with the V-6 and it went from 15 mpg to 23 on the highway and heat would cook you after a new timing set.
Are you sure you put in a 180 stat and not something lower? I have a 96 and the temp gauge reads different(200 is where your 210 is) and mine will stay just under 200 warmed up with a 180. Yours looks lower than where it should be. You can verify it with a scanner. You are in the same climate zone as i am so you really don't need the 180. I put one in because it won't stay below 200 in the summer. This is because aftermarket radiators have less fins than the original but that's another story. You can fool the pcm by putting in a resister if you relay want to keep the 180.
Looks like sooner than later, I’ll have some real work done to this truck. I’d like to upgrade to a double roller timing chain. Is there one brand that is better than another? I see plenty available for LA engines but I’m unsure if they’re compatible with our magnums.
Looks like I’ll be doing:
Timing Chain / Gear Replacement
Water Pump Replacement
195 t-stat upgrade
Is there anything else while I have the truck down for this work that I should tackle as well? As mentioned before; I don’t generally drive it long enough for these issues I’m having to become noticeable, however - I’d like to maximize the life out of this 5.9 Magnum as much as I can!
still deciding whether or not pulling the trigger on the Hughes airgap intake is really worth it for my daily driver. Granted, I’d like for the power to be there when I need it. But if the gains are minimal, I’m sure the factory kegger would suffice.
#22
10-16-2023 | 06:58 AM
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