Rattling in Engine Bay - High Pressure Fuel Pump -
 

So my 2015 TLX Tech (2.4L) has been making this rattling sound from the engine bay. Finally took it to my dealer to take a look at it and turns out the "high pressure fuel pump" needs to be replaced. They ordered the parts and it should repaired tomorrow. The Service Tech said it was a common problem and knew right away what the issues was when I mentioned it.

Got a case of DIFTL

(direct-injection for the lose)

Was it at least under warranty?

Fortunately it still is under warranty.

Good. The high pressure fuel pump and injectors are considerably more expensive than their conventional counterparts.

Maybe this is different, but for my car, 16' 4cyl, I got both chirping and rattling noises in the engine bay. They replaced that high pressure pump, which fixed the chirping noises. Sad part is the damn noise came back after a month. I have not taken back to the dealership yet. As far as the rattling noise, you might want to have them look at the tranny mount. I got that replaced, and the rattling is gone.

TSB out for that, see attached

Yup, I did saw that when I first notice my car starting to chirp during idle. I did had a hard time getting them to agreed and get it fix since that TSB is for v6 model and mine is a 4 cyl. I had to record a few videos clips and had that sent to the manager. As far as the rattle noise OP mentioned, I had a similar situation where they "can't" hear it or duplicate it. They replaced front shocks and front engine mount. They said they found those parts are bad, but that does not fix the rattle noise I had, plus when I hit the gas, I can hear a clunk. Finally they replaced the tranny mount, which took care of the rattle and the clunk noise.

OP, you said the car has rattle noise and they said it the fuel pump. Mine is cause by chirping, cricket like sound. The rattle noise is cause by bad tranny mount. So I want to give my experience of mine and see if they can check out those issues as well when you at the dealership.

Interesting. The sound that was coming from the engine bay from my 2.4L TLX was a rattling sound and it got worse as the engine got warmer. So a long drive on a warm day would make the most rattling sounds. Dealers said is was the High Pressure Fuel Pump. I just got my car back this morning. I didn't hear any noise while driving it to work but I will continue to monitor to see if I hear any more sounds. Thanks.

Well the rattling sound did come back and this time I also noticed a clunk sound when accelerating too. Haven't had time to take it to dealer until yesterday. I took it on a test drive with the tech so he can hear the rattling and the clunk sound. They determined that it was a bad transaxle mount causing the rattling and replaced it. They think it might have also resolved the clunk sound too since they took it for a test drive and couldn't replicate either sounds. They said that the clunk was also noted on my file just incase it comes back after my warranty expires. After I picked it up the car noises seem resolved. I will continue to monitor to make sure everything is ok.

Glad that fixed for you OP. Luckily your tech did hear the rattling and clunk sound and got that fixed asap. I took a drive with 3 different techs and they all said none until they gave up with me and decided to replaced the tranny mount, and that only took me about 8 visits in 1 year.
I think, sadly, the clunking will likely come back. My engine has a very low idle rpm, which causes the engine to vibrate. I asked numerous times if they can adjust the idle, and they all said NO. Hopefully I'm wrong, but this in long term will cause wear and tear on those mounts and I'll be back to square one again.