German Auto Repair in Eugene

(541) 683-5050
Work Hours
Mon - Thu: 7:30 AM - 5:30 PM

Intermittent Car Troubles


One of the daily challenges that we have at our shops is the diagnosis and repair of intermittent problems – things like noises, poor running, no start conditions, vibrations that don’t happen all the time.

In any kind of problem solving in any kind of profession, there are four logical steps to problem solving.

The first is to experience the problem.

From this you can move to step two which is to theorize what the problem is.

Moving to step three, you test, inspect, diagnose to prove or disprove your theory.

The forth and most important of the steps is you repair or replace the part in question to make sure your theory is correct. If that fixes the problem; the proof in the pudding, so to speak.

If the problem is not there all the time, you can lose two to three of these steps. This is where the challenge exists.

We have had vehicles that will crank over but won’t start. One of the first steps is to read the onboard ECU (electronic control unit) to see if any fault codes are present. If they are, we need to determine whether the component would cause the vehicle not to start? Unfortunately, many no-start problems such as a bad intermittent fuel pump don’t store a code.

In this case of a bad intermittent fuel pump, we can’t experience the problem unless it just so happens to fail on us. Otherwise, we can’t test the problem and can’t be sure that a new fuel pump will solve until it is installed and mileage put on the vehicle.

Noises and vibrations are another tough challenge. We have to experience them to be able to repair them. One thing is for sure, you can’t see a noise or vibration which makes the diagnosis tougher. The good news is I have never had a intermittent noise or vibration strand anyone. Sometimes the customer has to be patient until the intermittent problem becomes more prevalent.

At times when a vehicle won’t start, the customer needs to understand the problem might not get fixed the first time and a part that may seem logical to replaced ultimately doesn’t fix the problem. In this case, that procedure becomes part of the troubleshooting because all problem solving is the process of elimination.

So please keep in mind that modern vehicles are amazingly advanced, highly technical marvels that enhance your driving experience.


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