Dodge Dakota & Pontiac Bonneville

This weekly Q&A session answers your questions about cars and trucks. This week explores 2 cars from the year 2000: a Dodge Dakota with a gross DTC P0445 and a Pontiac Bonneville with a mysterious hum.

Question: 2000 Dodge Dakota

Error code P0445 EVAP emission leak gross. Where do I start to determine the problem?

History:

Had exhaust manifold leak last year, not leaking now. Any input will be appreciated

• 2000 Dodge Dakota 4x4
• 4.7 liter V-8
• Automatic transmission
• 150,600 miles
• Fuel Injection
• ABS brakes
• P/S, A/C, Cruise control

Thanks,

Gerald

Answer:

DTC P0455 means Evaporation Control System (EVAP) Leak Monitor Large Leak Detected. A loose or missing gas cap is the most common cause of this code. First thing to do is to check the gas cap and be sure it is on correctly and properly tightened. When tightening the gas cap, turn it until it stops and at least three clicks more. It is also possible the gas cap is bad.

Other than that the only thing to do is visually inspect the lines and hoses. With a "gross leak" the problem should be fairly obvious. If not, then go to the nearest Dodge Dealer. They have a machine that connects up with the EVAP system, pressurizes it and locates the leak.

Question: 2000 Pontiac Bonneville

Greetings! I have a 2000 Pontiac Bonneville with a recently acquired, moderately loud humming (or whirring) noise that comes from in front of the firewall and is ONLY vehicle speed sensitive. Sounds maybe like a pump or bearing? The general tone is constant with speed and simply slows as vehicle speed slows.

It becomes quite audible at about 30 mpg, louder with speed, and persists even after the ignition is turned off while at speed. I just had the transmission repaired for an P1811 code about 1,100 miles ago, if that is relevant, where they R&R the valve body, replaced the ERC (P&L) solenoid and boost valve, gaskets and filter. Sure hope you can give me a few things to look for.

Many thanks,

Jim Baker

Answer:

If the noise is there while coasting with the engine off, that narrows things down quit a bit. The first thing to suspect is the front wheel bearings. Try turning the wheel sharply from left to right while driving. If the noise changes, it's a wheel bearing. If the noise lessens when the wheel moves to the right, it's the right wheel bearing. If it lessens when the wheel turns to the left, it's the left wheel bearing.

If there is no change, then a mechanic would really need to drive it and listen to the noise. It could be a tire noise, transmission bearing, internal transmission problem or even a drive axle.

That’s all for this week. Feel free to browse the archives for past topics.

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