# X-Trail 2004 QR20DE rattling sound from engine on uphill



## gck1 (Jul 13, 2015)

So I noticed that when going uphill, rattling noise comes from engine when I press on the gas pedal. Only when the revs are in 2000-3000 range. This only happens on uphill though. I use premium fuel so that shouldn't be issue.

What should I look for? Is this what pinging is?

Also, another strange noise:
While going higher than ~40km/h, if I shift the transmission (ATT) to neutral and rev up the engine, when the revs drop to around 1200 - there's strange scratching sound lasting for around a second coming off from the center off the car. Like something is vibrating


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## rogoman (Dec 16, 2004)

If it's a pinging sound like dropping marbles on a table, then the engine is detonating. This could be due to an over-heated engine or an extremely lean fuel mixture. If there is a major vacuum leak in the intake system, that could cause it. Use a vacuum gauge for good accuracy to check for a vacuum leak; most auto parts stores sell vacuum gauges. To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source, usually somewhere on the intake manifold. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be around 21 InHg.

If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle body and at the MAF for cracks or loose clamps.

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The scratching sound may be due to a loose exhaust pipe connector or heat shield.


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