There’s a droning noise coming from my car. What should I do?

“Hi, lads, got a question from the UK. Got a Land Cruiser here, which is a Prado. Had a 2016 base model and upgraded to a 2017 invincible Prado. But now I have a droning noise coming from the exhaust system. It occurs at 1,500rpm. Went to Toyota and they said it is normal. But the 2016 model did not have this noise. Can any of you guys help, please? PS. The mechanic said that a few customers have the same complaint. The UK is not a big market, so they may not have all the answers.”

Thomas McAuley 

Dear Mr. McAuley,
 
We’ve looked into your problem in various Land Cruiser Prado online forums. As far as we can tell, the exhaust droning you’ve described suggests that you might have a problem with your unit’s DPF.

DPF stands for diesel particulate filter, which is designed to control the amount of soot particles and nitrous oxide (from the combustion process) that is emitted through the exhaust system.

In Australia, the Land Cruiser Prado is the best-selling large SUV. Many Prado owners there have also complained about exhaust droning. And, much like the response you’ve received from the dealer, they were told that their vehicles were operating within the specified parameters.

It has been suggested that Toyota resolve the problem with additional sound-deadening materials in the Prado’s interior. As of 2018, however, this has yet to be done. 

Some solutions advocate deleting the DPF altogether, but such a solution may not be legal in certain places. Also, deleting the DPF may have adverse effects on the vehicle’s ECU, which monitors the performance of the DPF as part of emissions compliance.

Another solution is to add another muffler downstream of the DPF. This suggestion seems to be the most viable one. It does not run afoul of emissions regulations, and your vehicle should pass regular emissions testing. More important, it serves to address your complaint effectively and squarely.

We cannot perform a complete diagnosis of your vehicle problem, but based on your description as well as similar complaints that have been expressed by other owners from around the world, we think the foregoing suggestion might solve the issue.

Thanks for writing in!