Gas mileage significantly reduced following a number of engine tunes (see list below). I used to get 22mpg. Now getting 18mpg. Also seems to be running hot. Hoping I can get some ideas on root cause and fixes...
’99 XC70, 95K miles, Denver, CO (Purchased new in CT)
Recent changes:
• Air filter (drop in K&N)
• VVT Solenoid – Had a CEL with a P1332 code, which is for the solenoid. Removed solenoid, and tested it to be bad (powered the terminals and it clicked but didn’t slide). Purchased new one and installed. Slightly different design, but same mounting footprint. Was told by Volvo it was the replacement for the original part. Have not had CEL since.
• Replaced heater core (was leaking into passenger compartment) I may be imagining this, but it seems to be running hotter since then. The temp needle is now exactly horizontal, in the center, when at operating temp and I had thought previously it normally ran noticeably below center.
• Oil change (Valvoline high mileage synthetic blend)
• New cabin air filter (aftermarket carbon impregnated)
'99 XC 70 - Gas mileage loss
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Ozark Lee
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The temp gauge at the 3:00 position is absolutely perfect. It is curious that you were below that on temp before the core change.
When was the last time you changed spark plugs? Particularly if you are running Bosch FR7DC plugs (the plugs that I run in my cars) they give out at about 30k miles. What happens is that the gap expands substantially but I just put in a new set and gap them rather than regapping the old ones. They only cost about $1 a pop + whatever the little pack of antiseize compound costs at the checkout counter.
...Lee.
When was the last time you changed spark plugs? Particularly if you are running Bosch FR7DC plugs (the plugs that I run in my cars) they give out at about 30k miles. What happens is that the gap expands substantially but I just put in a new set and gap them rather than regapping the old ones. They only cost about $1 a pop + whatever the little pack of antiseize compound costs at the checkout counter.
...Lee.
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe
Plugs have about 15K on them. Could try that just to be sure and and replace them. What do folks recommend (or recommend avoiding) for plugs? Don't mind paying a bit more for better performance and/or longer lasting. What is the torque spec for the plugs on these cars?
Had another thought: Any chance I didn’t do the VVT solenoid replace correctly ( e.g. I reversed wiring) and it's not working, so I'm stuck in one of the two valve timing cycles and not benefiting from VVT? Any way this can happen without triggering a CEL?
Had another thought: Any chance I didn’t do the VVT solenoid replace correctly ( e.g. I reversed wiring) and it's not working, so I'm stuck in one of the two valve timing cycles and not benefiting from VVT? Any way this can happen without triggering a CEL?
'05 XC70
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