About ~1 month ago my RX450H 2015 gas engine has started to sound rough while idling or driving at slow speeds. Very recently it has started to make a very ugly "squirting" or scraping sound as if a pump line is struggling. Please listen to the video and give me any advice. Of course when I went to go video the noise it was not nearly as bad as scary as when we fired it up this morning to take the kids to soccer! I will try again later today to capture the sounds a bit better.

Previous to ~1 month ago the engine was very quiet and even this grey noise was undetectable. Something sounds loose.

 

How many miles on the car?

 

Mileage on the 2015 RX450H is 66,800 miles.

New video with more of the quick scraping sounds.

 

Was that the A/C compressor activating half way into the video?

 

The second video? I'm talking about the second video now: It's the gas engine staring up at the 7 second mark. You can then start to hear scraping and knocking sounds. Initially, I think it's some of the pumps and perhaps the cabin AC you can hear.

 

Ah okay, initially I am hearing fans/pumps like you say. Water pump or belt tensioner? Not much on your car external to the engine rotates outside of electric motors.

 

Sounds like something loose clanging around down there.
I would crawl underneath to pinpoint the location. To me it sounds like a loose bracket or hanger somewhere.

 

Did you get this resolved? I am having the same sound on idle/starting. The car also sometimes gives faultcode P0300 "misfires". I can feel the car misfiring. After a few seconds the noise goes away. On accelerating i feel a slight shivering from the gas engine. On battery no problem. When the engine gets warmer the engine runs almost perfect. Almost because far away i can feel it misfiruing. A few months ago i replaced the sparkplugs with ebay oem. I had this same problem on a Prius C. After replacing those sparkplugs the problem was solved. Any idea what it can be on the RX450H. about 70kmls

 

You are lucky as your cause of the problem is being displayed and can be read. A misfire [different from back-fire] causes the engine to run with missing beats and you loose the smoothness is sound and power. Are you experiencing the misfire even after replacing the spark plugs? If yes then the next suspect is the ignition coils. Normally for misfire on certain cylinders, the diagnoses requires swapping plugs only and then the coils only from a good cylinder.

Salim

 

Thank you for your reply. Good thing that you pointed me to the coil. This morning i read the misfire counts in the datastream from the obd scanner. I noticed that cilinder 1 is misfiring constantly. Cilinder 2 a little and the rest 0 misfires. So i eleminated the problem to cilinder 1 and 2. Thanks to your reaction i will first swap coils and see what happens. I am allready looking for injectors. Read that it is also a common problem.

 

In the process of debug by swapping, I would suggest leave #1 alone for now and focus on #2 suspect and use #4 known good for swapping. The advantage is that #2 and #4 are in the front (near radiator side).

My input is that don't jump on injectors just yet. RX has port injection and if it was direct injection then injectors jump up in rank of possible failures. If you have been using good gas and have kept 1/4 tank or higher the injectors should be low in the suspect list.

Salim

PS: The issue being discussed here does not belong to 450H specifically.

 

I changed position of 2 and 4. Even after the change 2 kept giving me the faults. I usually fill up above 1/4 tank. I had this before a few months ago. It was also raining heavy in my erea. I than thought there might be some water in the gasoline. After a refill the problem went away. Now the rain is heavy again and this time the problem stayed after the refill. Sparkplugs were also changed a few months ago for oem plugs. Nowadays there are also good imitation of oem products. Tommorow i will also change plug 2 and 4. If the problem stays at 2 than i think i have an injector problem

 

The swap process is a multi step as there are two potential source of issues coil and spark-plug. If you swapped the both the coils and plug at the same time and the problem remained in 1 then you can potentially rule out the coil and plug together.

I prefer moving one item at a time ..
Spark plugs2 &4 swap only -> no change plugs are ok and if the problem moved then the old plug 2 is bad.
If no change: Plugs are good and they can stay in the new locations
Swap coil pack 2 with 4 and if the problem moved then old coil 2 is bad
If no change then coil packs are ok.

How was the visual inspection of plug 2? Damp from misfire or crud from deposit.

I love DIY but I know my limits ability/tools and if the issue is beyond coil & plug replacement, I would reach out to professional help.

Salim

 

Removed and replaced plug 2 and 4 this morning. Problem stays at cilinder 2. Sparkplug from 2 looked like a lean burner. very white. 4 seemed ligyht brownish. I will replace the injectors. Will let you know what the outcome is.

 

No fuel or lack of fuel is not a misfire situation. I have come to this conclusion based on when you run out of fuel, the message is not misfire.
To me me misfire is ignition at wrong time.

Salim