Threeper88

Why not? I could guess but what do you think?

Nicklaus

I guess you’re right. However, I don’t see anything wrong if a manufacturer explains an odd engine behavior caused by a programmed algorithm. Most of us would be relieved...I think.

For some reasons, manufacturers don’t do that and keep all this secret with annoyed Customers.

lawndart

This is one of many theories on the problem, each of which have just of much evidence to support as disprove. My decell rattle appears heavily oil pressure dependent, and mechanical. There is no hard evidence to confirm any of them yet, nor is there a fix.

Nicklaus

Okay forum, I was wondering if an oil change would change anything with that noise. Some of you mentioned the decel rattle noise appeared following the first oil change.

My truck did the noise in drive with factory fill oil and just decided to do an oil change and filter...just to learn something.

before oil change: cold engine, parked in the garage, no rattle In neutral, rattle in Drive (while holding the brake pedal). I even made a video for my dealer.

after oil change: cold engine, parked in the garage, no rattle in Neutral, NO RATTLE IN DRIVE. I tried again and again...no more noise!

How can it be? Ok, beer time, I’ll report back next time I take my truck with a cold engine, too good to be true.

species8472

It will come back as the oil gets used and clumps start to form.

species8472

You can test this if you have the tools. The solenoid/phaser control is pulse-width modulated (PWM). You can intercept that and modify the signal to make the PCM thinks the response time is in specs and it won’t do cleaning and no rattle.

Or you can just unplug the solenoids. This will set a DTC but no signal to solenoid and no deceleration rattle.

5Lgreenback

I remember reading in one of the threads about people trying different oils and such. Appeared to have no effect, or no improvement anyways if I recall correctly.

What did the dealer say when you brought up the noise?

Threeper88

Too good to be permanent

Nicklaus

If my truck's fix is to keep oil clean, just watch me...

I made the video for my dealer, but did not send it yet. I'll wait a bit to see if this improvement lasts or not.

Unfortunately, I do not have tools nor the knowlegde. but it sounds interresting and I keep this as an option for further diagnostics. Is that something that you tried yourself ? What do you excatly mean by modifiyng the signal ? Adding an electronic filter or a gain?

This is what I think too. I hope that you and I are wrong. Since I was getting pretty good to reproduce the rattle noise, I was very surprised when I wasn't able to reproduce it anymore right after the oil change. By the way, I did not fill it with Mortorcraft...

lawndart

That doesn't prove anything. Of course unplugging the solenoids stops it. Modifying the signal doesn't convince the PCM the response time is in spec. It changes the demand for cam movement. Your reaching with your theory.