Odd engine behavior
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Joined: Apr 2024
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Odd engine behavior
I am trying to diagnose a strange behavior in my 2011 3.5 Ecoboost (177k miles). Under hard acceleration (uphill), it stumbles. It does not feel like a tranny shudder. more like skipping a beat every second or so. Both 5th and 6th gear.
The spark plugs have less than 10k and I have done the weep hole mod on the CAC. It does spews the coffe-looking stuff. But here's the strange thing. It seems to be a problem only when I am driving above 6,500' elevation, and mostly
when the engine is warm. This morning a started the drive at 6500'. With the engine (and transmission) on the coldish side, no issues. Later, when I was still above 6,500', I experienced the problem. Later, down at 1,000' no issues, no matter how hard I frove it (engine and tranny warm).
The only code that I occasionally get is a Bank 1 converter below threshold. It comes and goes. No other codes. Aside from that the truck runs good. Any ideas?
The connection with elevation is odd. It is a turbo engine, elevation should have little impact on the performance.
The spark plugs have less than 10k and I have done the weep hole mod on the CAC. It does spews the coffe-looking stuff. But here's the strange thing. It seems to be a problem only when I am driving above 6,500' elevation, and mostly
when the engine is warm. This morning a started the drive at 6500'. With the engine (and transmission) on the coldish side, no issues. Later, when I was still above 6,500', I experienced the problem. Later, down at 1,000' no issues, no matter how hard I frove it (engine and tranny warm).
The only code that I occasionally get is a Bank 1 converter below threshold. It comes and goes. No other codes. Aside from that the truck runs good. Any ideas?
The connection with elevation is odd. It is a turbo engine, elevation should have little impact on the performance.