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Diesel Like Engine Sounds From My 2005

By Skeletor, March 19, 2012



Hi! I have a 2005 with about 92k miles. In the last 5-8k miles, my engine has sounded almost like a diesel. It happens at all speeds but it's more noticeable at idle and low speeds. It also seems like my gas mileage has suffered. Car runs fine and shows no other ill effects other than the loud noise. Does anyone have any insight into what this could be? I'll try to post a video later when I head out to lunch.

Failing timing gear? Unusual on a 2005, but such failure can be catastrophic... Standing by for video with audio.

Could be a number of things causing that noise. Assuming that the basics are checked out already - check for leaky fuel injectors, worn or fouled spark plugs, dying coil on plug igniter, lazy AFR sensor, dirty MAF/IAT, gummed up throttlebody, etc. If all of those are fine, then the most likely culprit left for this particular engine generation would be some component in the VVTi system. In particular the OCV (Oil Control Valve) and the associated OCV filter. Generally not touched under normal maintenance, the filter especially, can get gummed up with particulates. When this happens, the OCV is starved for oil pressure and the VVTi system cannot accurately set the timing. This can cause all sorts of noises - pinging from detonation, wrong valve overlap causing poor performance, and generally hurt fuel economy overall.

The 1ZZ-FE engine is pretty noisy to begin with, so it can be tough to pinpoint. The video clip will be helpful, as if it is the VVTi issue - it has a very distinct sound to it. Also would be helpful to know a little more about the vehicle history, especially in terms of maintenance or lack of maintenance; driving conditions, how it is driven, etc.

Could be a number of things causing that noise. Assuming that the basics are checked out already - check for leaky fuel injectors, worn or fouled spark plugs, dying coil on plug igniter, lazy AFR sensor, dirty MAF/IAT, gummed up throttlebody, etc. If all of those are fine, then the most likely culprit left for this particular engine generation would be some component in the VVTi system. In particular the OCV (Oil Control Valve) and the associated OCV filter. Generally not touched under normal maintenance, the filter especially, can get gummed up with particulates. When this happens, the OCV is starved for oil pressure and the VVTi system cannot accurately set the timing. This can cause all sorts of noises - pinging from detonation, wrong valve overlap causing poor performance, and generally hurt fuel economy overall.

 

The 1ZZ-FE engine is pretty noisy to begin with, so it can be tough to pinpoint. The video clip will be helpful, as if it is the VVTi issue - it has a very distinct sound to it. Also would be helpful to know a little more about the vehicle history, especially in terms of maintenance or lack of maintenance; driving conditions, how it is driven, etc.

Normal driving conditions in the south. Nothing exceptionally hot or dusty. The oil gets changed every 5k religiously. Mostly the car is used to commute about 15 miles to work and normal around town driving.

It doesn't sound to be an ignition problem. I pulled the plugs about a month ago and all looked fine and normal. I changed them at that time and the sound is still present. The engine has always been a bit noisy, as it seems all of them are, but this is different. Again, it doesn't feel like it's affecting the performance other than a slight loss in gas mileage. Even that is minute, I went from getting about 32mpg to 29-30mpg. I don't even know if that's significant enough to even be a symptom.

Of course I go out just now to record it and the noise isn't as obvious. It's more pronounced when the engine is cold and it still had some heat in it because of the warm day today. Looks like I'll have to wait until the morning for the video.



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