ft1980

There's a ticking sound coming from the engine bay. It's connected to the revolutions of the engine. In other words, if i give it a little throttle, the ticking speeds up proportionally, until the rpms go about 2,000 rpms or maybe 2500. Then it usually goes away. If I were to guess, I'd guess lifter noise.

When idling, it randomly goes away and randomly comes back. However, as stated above, if I rev the engine enough, it USUALLY just goes away. And then it may restart after some time when the rpms lower, but not always immediately.

Ticking seems to be independent of whether or not the engine is warm or cold.

One thing to note is that I did an engine oil and filter change today myself. I was a bit disturbed to see that it seems like a little over 5.5 quarts drained out. I never go by mileage. I just change the oil when the maintenance light comes on. Does anyone have a clue if this is based on miles driven or rpms?

Does anyone have a guess as to what the ticking sound is and what I should do to narrow down possibilities? Thanks

2012 Lexus RX350 AWD
150,000 MIles

RX in NC

At your stated mileage (150,000), it could be the VVT (Variable Valve Timing) system ticking. Not uncommon for a high-mileage engine, and you may not need to do anything about it at this point. Some VVT systems tick when the engine is first started, then the ticking diminishes as the engine warms up.

carguy75

Just a guess from a keyboard based diagnosis.

As stated above, it seems that you may have a bad VVTI gear which start off as ticking and then it could become worst(complete failure and engine damage) if not addressed. I say this because the ticking persist even after the cold start-up. Toyota VVTI engines are pretty noisy at cold startup, but usually quiet down after a few minutes when the oil pumps up the VVTI actuators.

I would have a mechanic check it out and prepare for a large repair bill if new VVTI actuators are recommended.

salimshah

I have only seen engine run time based info in commercial engines. Depending on equipment it can be simply run time and in some to rotations. For consumer level things the service interval is convenience based number. If two consumers drive at 1500 rpm and 3000 rpm respectively, the service interval should be halved for the second.
My understanding is for RX is, it is based on milage and calculated from the last 'reset' and triggered when the 'service interval' is reached. Service interval is typically set at the point of sale by the dealer and for the 3rd gen it is 10k miles.

Salim

Clutchless

I recall that on all of the 2008 - 2012 Lexus vehicles I have owned or worked on the oil maintenance light goes on at 5,000 miles. Now Lexus did increase the oil change interval to 10,000 but on all the cars I have seen, they did not change the maintenance light interval from 5,000. I think it was to increase their service department business.

The engine holds 6.5 quarts so you were a quart low before the oil change which may have contributed to the noise. Did you fill it with 5.5 quarts or 6.5 quarts?

ft1980

I filled it to the middle of the recommended dipstick level which ended up being just short of 6.5 quarts. The missing quart is a bit of a worry for me. Maybe I screwed up and underfilled it last time, but I'm pretty careful about simple things like that and I'm 90% positive I filled it correctly. My routine is to:
1. Fill the oil until it's at the max recommended level.
2. Start engine and let it idle half a minute to fill up the filter.
3. Recheck the oil level and fill up to the recommended oil level.

The missing quart also crossed my mind as a possible culprit.

What do most people find for oil consumption on these cars during 5,000 miles or whatever the oil maintenance schedule is?

Clutchless

Usuallly I have no oil consumption after 5,000 miles.

carguy75

My RX350 usually loses about half a quart(about 6 quarts drain out from the 6.25 I put in) when I change my oil when the oil maintenance light comes on(around 5k miles), however I do have a couple of small leaks in my engine from a seeping timing cover and weeping lower oil pan seal that explains the loss.

I would also change you PCV valve as an old sticking one can allow oil to be sucked into the intake manifold from the valve cover; which could be a source of your oil loss. In addition, small seal leaks(front timing cover, valve covers,oil pans, oil lines,etc) could be another source of your oil loss as well.

RX in NC

No noticeable engine oil consumption in my wife's 2015 RX350 FWD, now at just over 91,000 miles. I run the required 0W20 full synthetic oil and change the oil and filter cartridge at the recommended 10,000-mile intervals.

I would not trust any dealership service writer's "recommendations". I believe all of them essentially follow the same business model nowadays which is to attempt to extract as much money as possible from each and every customer.

Clutchless

I run an oil mix recommended by some engineer on the BobistheOilGuy forum. I started using 4.5 quarts of 0w20 and 2 quarts of 0w40 Mobil 1. I find this reduces engine noise on start up and may provide a bit more protection than just running 0w20. Mileage appears unaffected.

paperthin

Interesting. I would have gladly tried this but we take ownership of our 2023 350h this Saturday. Our startup noise increased over this last year, even on some warm starts. Can't complain after 332k km.

ft1980

Went to the dealership today. They were a bit shocked to hear the ticking since the 3.5 is known as being a bulletproof engine. Anyways, the tech looked at a sample of oil from the oil filter. It was black while the oil up top from the dipstick was clean and new. There were some very very small metal flakes. No engine light ever came on. Trying to figure out what to do. Most likely will just trade in the car.

Clutchless

Time to get a second opinion from an independent shop and / or trade it in.

RX in NC

Yep, get a second opinion before you take any further action.

I would not refer to these engines as "bullletproof". The infamous timing cover oil leak issue automatically disqualifies them from that category.

carguy75

I concur with that statement.

Toyota engines are the most reliable compared to most of the competition, but Toyota lost that "bulletproof" reputation in the late 90' s up to now. The V6 engines has been prone to sludge(3.0V6), oil leaks(3.5), water pump failures(3.5), VVTi failures( 3.5), etc. The 2.4 engine was even worst in terms of reliability(head stud issue). However, all and all an Toyota engine will give you your money worth in terms of long term usage before the engine needs to be replaced. Most of the major issues has been corrected over the years.

The competition engines are much worst in addition to the same problems Toyota has; usually in form of broken timing chain guides(BMW,Ford,GM,Audi,Land Rover, Nissan, etc.) that ends in a major engine rebuild just over 100k miles.