Rattle on cold start and burning oil

[DrTuukka]

Hello All,

I’m hoping you guys can help me get to the bottom of this. I’ve been dealing with this for a few months now and it’s been driving me absolutely insane recently. I own a 2018 Explorer Sport with 84k miles, and I drive roughly 500 miles a week. I bought it with 30k on it in March 2021, and (naturally) everything had been going great until I passed 70k miles in June of this year.

On cold starts, there is a rather noticeable rattle noise coming from the passenger side. If I were to turn off the car and turn it back on shortly thereafter, there’s no rattle noise likely due to the oil pressure already being built up. In addition to this, I have also noticed at high-rpm, when idling or at low speeds (1st & 2nd gear), the same noise is very clearly heard.

When coasting through my neighborhood (low speed), I notice a “popping” noise that sounds similar to bubbles being popped in rapid succession. This noise is also prevalent after I let go of the accelerator.

I took it to Ford about a month ago and instead of thoroughly investigating it, they just changed the oil and said “Look! The noise is gone!” but by the time I picked it up, the noise was still there. I pointed it out to them and they don’t have time in the near future to fit me in their schedule.

I have recently also noticed that it is starting to burn oil on start-up as well, with a puff of blue smoke and a rather excessive amount of white smoke following shortly thereafter.

I’m a rather mechanically inclined person, but I haven’t done engine work before. I’ve pointed it out to other car-loving friends and they’re pretty stumped themselves.

Thanks in advance!

 

[DrTuukka]

Struggling to post the videos.

 

[mguy13sport]

Cam Phasers are notorious for the cold start rattle. Its common on the ecoboost 3.5 especially the F150. The explorer uses a transverse setup which is why you don't hear it on the driver side.

I would at least try to pull the front valve cover and inspect the phaser and timing chains. It may need a timing job + new phasers.

They make an aftermarket high volume oil pump now which can push more oil on cold starts.

Fyi - You can prime the oil pump by holding down the brake and gas at same time while pushing the start button for a few seconds. It will just crank without starting. Then just let off the gas abd start it normally and it probably wont make any rattle on cold starts.

 

[boominXplorer]

Most the rattling comes from poor sealing turbo wastegates. Combo'd with smoke on startup I'd say you need a turbo at minimum. The noises could still be timing related but oil out the tailpipe is most likely turbo.

 

[mguy13sport]

Oh ya I missed that part - smoke on startup is usually a leaky turbo for sure. Surprised Ford didn't inspect that when they changed the oil since the Turbo's easily visible underneath when on a lift.