Diagnose my engine problem
#1
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Diagnose my engine problem
My engine makes a horrible sound while above 6K rpms. It is hard to describe the noise, it's a shuttering sound like there are loose marbles within the engine. Maybe this is similar to piston engines when they ping. I suspect it is pre-ignition.
Other factors:
It doesn't always happen.
It seems to mainly happen in 4rth gear. It hasn't happened in 1st or 2nd.
The engine is a streetported s4 na with s5 internals, using a Microtech LT10. (It has been tuned on a dyno and this noise was reported to me by the mechanics who worked on it. I don't believe it's due to bad tuning because I vaguely remember hearing the noise prior to the installation of the microtech. The shop is top notch with lots of experience.)
Please suggest all possible diagnoses and fixes.
Other factors:
It doesn't always happen.
It seems to mainly happen in 4rth gear. It hasn't happened in 1st or 2nd.
The engine is a streetported s4 na with s5 internals, using a Microtech LT10. (It has been tuned on a dyno and this noise was reported to me by the mechanics who worked on it. I don't believe it's due to bad tuning because I vaguely remember hearing the noise prior to the installation of the microtech. The shop is top notch with lots of experience.)
Please suggest all possible diagnoses and fixes.
#2
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Location: Orange Park FL (near Jax)
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Originally Posted by buzz2
My engine makes a horrible sound while above 6K rpms. It is hard to describe the noise, it's a shuttering sound like there are loose marbles within the engine. Maybe this is similar to piston engines when they ping. I suspect it is pre-ignition.
Other factors:It doesn't always happen.
It seems to mainly happen in 4rth gear. It hasn't happened in 1st or 2nd.
.
Other factors:It doesn't always happen.
It seems to mainly happen in 4rth gear. It hasn't happened in 1st or 2nd.
.
You have a near fatal engine.
Do not drive in that zone until it's fixed.
If that tuner dosen't recognize rotary detonation, you need a different tuner.
#5
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i had a small detonation problem that was only noticable when climbing hills. turned out just to be a timing problem. from what i've read the n/a 13b engine was made to run on 80 octane gas. so if your filling up with 87 your good to go. if you premix then you getting a lower octane rating.
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