Ford Expedition Check Engine Light Fuel Consumption

I understand your frustration. The symptoms you describe – check engine light and increased fuel consumption – are consistent with a VANOS issue. The variable valve timing system, VANOS, relies on precise oil pressure and functioning solenoids to adjust camshaft timing. A faulty camshaft solenoid valve, as your shop suggested, is a plausible cause, as is an intermittent power supply to the solenoid. Do you have any error codes that might shed light on which bank is affected?

Thanks for the reply! Error codes, huh? I didn't think to ask for them at the shop, and I don't have a code reader myself. Is there a big difference depending on which bank is throwing the code? Would that change the likely culprit or repair process?

Yes, knowing which bank (Bank 1 or Bank 2) is reporting the fault is crucial. Each bank corresponds to a specific cylinder head. The diagnostic trouble code (DTC) provides insight into which camshaft and, consequently, which solenoid valve is experiencing the issue. While a faulty solenoid is a common cause, consider verifying the integrity of the timing chain and checking for potential oil sludge accumulation, especially given the mileage of your vehicle (118085 km). I recommend returning to the shop and requesting the specific DTCs. Based on your description, a workshop visit is advisable in any case.

Alright, thanks a bunch for the detailed info! I went back to the shop and got the error codes. Turns out, it was a camshaft solenoid valve on Bank 1. They replaced it, and the check engine light is gone, and fuel consumption seems normal again. The repair cost me about 250€. Hopefully, that's the end of it!