MIRX450H

I have found that when I accelerate quickly, while entering the expressway or getting around a semi for example, a burning smell enters the car. I imagine it's oil but uncertain. The smell occurs shortly after the quick acceleration and it doesn't occur consistently.
Has anyone else experienced this, any ideas on the cause?

corradoMR2

hmm... on my previous RXh never had that symptom. Maybe kitlz or other h owners can respond.

What will help is age/mileage of your h and what diagnosis have you done at all. i.e. are you able to stop the car immediately after the smell, go outside and determine where it is coming from? How does the engine oil color look like? Any leaks you see underneath? etc...

Gene01

You might try revving the engine with the car parked in the driveway with the hood open to determine the source of the smell. You will then know if the car has to be moving or not.

Cruiter

Have you recently changed your oil? Often when removing the old filter some oil may come in contact with the exhaust system. If that happens, a bit of burning oil smell could come up, especially if you've goosed it to pass and the exhaust is 'smokin ' hot. If not something goofy like this I haven't a clue. Never happened with me.

MIRX450H

The car is a 2010 with about 26k on it.

MIRX450H

I wondered if having an oil change done had something to do it with, but the last oil change was done about 1k miles ago. I didn't notice the smell immediately after that oil change. Just seems to occur on random occasions.

MIRX450H

I like that idea as it would give me a change to potentially diagnose the smell while parked in safe location. However, not sure how to 'rev' the engine of my hybrid while it's parked.

Wht95scort

The smell could be sulfur "rotten egg" smell due to poor gas. If this is the case try another gas and or grade.

Other is the oil cooler lines. They have rubber hoses that may get a pinhole and leak and when they leak they leak. You can look under the front passenger bumper it's right above the oil filter housing. Removal of the small shield to view will be needed.

chuckGS350

Have your service dealer checked it out.

L-SB-0154-11

December 21, 2011

Oil Cooler Pipe Seep
Service Category
Engine/Hybrid System

Some 2007 - 2011 model year RX 350 and 2010 - 2011 model year RX 450h vehicles may exhibit an oil seep from the engine oil cooler pipes.

MIRX450H

Thanks, I'll have that checked out by my service advisor.
I'll post an update once I have this thing figured out.

Thanks for everyone's input!!

Clutchless

They have metal replacement oil cooler pipes now, which they should have used in the first place when building the car. There is an extended warranty on the rubber oil cooler hoses, which Lexus mailed out several months ago.

As one who changes his own oil, there is no way to get oil on the exhaust when changing your oil unless you miss the fill hole on top of the engine when pouring in the new oil. It could be other things such as a valve cover or oil pressure sender switch that are know wear issues on most cars.

Or you could have an emission malfunction or carbon build up causing the sulfur smell. a bottle of Techron Fuel System cleaner a few times a year helps keep the fuel system clean.

raylor4

I've noticed this lately on my '04 Highlander which has the same engine, when doing "spirited" freeway driving. Burnt oil smell coming into the cabin briefly. Clears up after a few minutes. I'll check under the hood and under the engine for oil seeping, and get back to you.

MIRX450H

I believe I have discovered the origin of the smell.

There are vents beneath the rear seat which allow air to reach the Hybrid batteries. Because of my children I have a towel on the back seat to catch the crumbs, etc. While cleaning the car this past weekend I noticed a portion of the towel was covering the vents...all three of them.

I removed the towel, went to the expressway, quickly accelerated...no smell. Problem resolved..... I believe. If smell returns I will update this post.

Now to figure out how to cover the rear seat in such a way that those vents are no longer blocked/covered. I am considering car seat covers but have yet to come across one that looks decent.

Cruiter

This solution will certainly work. NO eating in the car. Yea, I understand backseat munching might keep them occupied while you're driving but covering the vents is not a good solution if you're smoking the traction batteries with heavy drain. Are they old enough to play with tablets rather than food? Also nothing to clean up that way .

I'm just a practical realist .

raylor4

Now to figure out how to cover the rear seat in such a way that those vents are no longer blocked/covered. I am considering car seat covers but have yet to come across one that looks decent. MIRX

This may sound crass, but I would look at car seat covers meant for pets. Places like Bed Bath & Beyond, online catalogs of household items, Google "car seat covers for pets". I've seen these pictured in many places, but can't name one. I'm thinking that these car seat covers will have elastic or snaps to keep them in place, away from the battery vents. I would pick a nice dalmatian or zebra pattern. : )
Ray A.