Hello everyone,
I'm reaching out for help and advice.
I own a 2005 Mustang GT 4.6 V8, manual, totally stock, with around 280,000 kilometers on the engine.
I'm located in Germany, and unfortunately, it's very hard to find qualified mechanics here who are familiar with this kind of car — especially when it comes to proper diagnostics.
Here are the issues I'm currently experiencing:
1. Engine stuttering on the highway
Occasionally, at around 80 MPH (130 km/h), the engine starts to stutter.
Shortly after, the check engine light comes on and stays on.
A mechanic once read out a misfire code related to Bank 2, but I don't have the exact code anymore.
2. Throttle hesitation at low RPM
The engine doesn't respond properly to throttle input between 1,000 and 1,800 RPM.
At idle, the engine runs smooth — no rough running or shaking.
However, there are occasional misfires at the exhaust.
This might be normal, but I have no other stock Mustang nearby to compare.
3. Overheating after shutdown
When shutting off the engine, the cooling fan does not continue running.
A few times, after turning off the engine, the coolant temperature briefly spikes into the red for about 3–4 minutes, then drops back to normal.
I'm not sure if this is an issue with the cooling system, a sensor, or fan control.
4. Soot marks near the fuel rail
I've noticed two soot streaks, each about 1 cm wide, near the gasket under the fuel rail.
Could this indicate a leak or combustion residue?
My goal:
I truly love this car and want to keep it on the road here in Germany.
I want it running properly again — not just for reliability, but because it still turns heads and makes BMWs and Mercedes look silly.
Can anyone give me some advice on what to check or what common issues could cause this combination of symptoms?
What tests should I have done, or what components should I look into first?
Thanks in advance for your time and help!
Best regards,
Jens
I'm reaching out for help and advice.
I own a 2005 Mustang GT 4.6 V8, manual, totally stock, with around 280,000 kilometers on the engine.
I'm located in Germany, and unfortunately, it's very hard to find qualified mechanics here who are familiar with this kind of car — especially when it comes to proper diagnostics.
Here are the issues I'm currently experiencing:
1. Engine stuttering on the highway
Occasionally, at around 80 MPH (130 km/h), the engine starts to stutter.
Shortly after, the check engine light comes on and stays on.
A mechanic once read out a misfire code related to Bank 2, but I don't have the exact code anymore.
2. Throttle hesitation at low RPM
The engine doesn't respond properly to throttle input between 1,000 and 1,800 RPM.
At idle, the engine runs smooth — no rough running or shaking.
However, there are occasional misfires at the exhaust.
This might be normal, but I have no other stock Mustang nearby to compare.
3. Overheating after shutdown
When shutting off the engine, the cooling fan does not continue running.
A few times, after turning off the engine, the coolant temperature briefly spikes into the red for about 3–4 minutes, then drops back to normal.
I'm not sure if this is an issue with the cooling system, a sensor, or fan control.
4. Soot marks near the fuel rail
I've noticed two soot streaks, each about 1 cm wide, near the gasket under the fuel rail.
Could this indicate a leak or combustion residue?
My goal:
I truly love this car and want to keep it on the road here in Germany.
I want it running properly again — not just for reliability, but because it still turns heads and makes BMWs and Mercedes look silly.
Can anyone give me some advice on what to check or what common issues could cause this combination of symptoms?
What tests should I have done, or what components should I look into first?
Thanks in advance for your time and help!
Best regards,
Jens