Noise & Shake when starting 2002 Forester

ken_s

For a few years now our 2002 Subaru Forester 2.5L I4 has periodically (about 1-4 times per month) had problems starting. When we cold start the car, a loud noise comes from the engine and the car sometimes briefly shakes. The problem began a few years ago primarily during winter months (~32 deg F) with the car starting. Now the noise level and the shake are worse and the problem occurs during summer (80 deg F) with the car reluctantly starting some of the time. In either situation, the car starts normally once warmed up.

The Subaru dealer can't find the problem because it's so erratic; they've looked at it about 4-5 times. We've replaced the normal items (plugs, battery, PCV, air cleaner, X-msn fluid) and checked the starter bolts.

Any suggestions?

paisan

Sounds like the check-valve on the fuel supply system. This keeps the line pressurized overnight or over a period of time. Try turning the car into the "on" position for 5 seconds before starting it so the fuel pump can pressurize the line. If this method fixes the problem then it's likely one of the check valves in the fuel supply system.

-mike

ateixeira

Are the plug wires original? If so replace those next.

After that I'd swap out the ignition coil. For my '98 that cost $80.

paisan

Could also be a vaccum leak as well.

-mike

ken_s

Thanks all for the advice.

We've been waiting a few seconds before starting the car. I'm happy to say that in the past three weeks, the problem has only occured once when we didn't wait. I'm looking into replacing the fuel check-valve, but can't find it on my car. Would a fuel injector pressure regulator or fuel tank pressure sensor be the same thing?

The wires are original, but appear to be in good shape.

I hope it's not a vaccum leak as they are hard to find.