Rx450H White Smoke From Rear Of Car

[Mapman]

Hi, I was driving my rx450h quite happily along the motorway and when joining a slip road suddenly noticed a huge amount of white smoke coming from the rear of the car. It lasted approx 1 minute or so as slowed the car down worried what this could be ? Has anyone had a similar occurrence ? having looked through the Internet it could be anything from condensation ( although I had been driving for over an hour at that stage ) to head gasket to overheated brakes ? Not sure but worried none the less. Any help or advice welcome. Thanks

[ChrisKaye]

Hi,

Have you done any visual checks?

Check your coolant level at the expansion bottle, check the oil filler cap (unscrew and look underneath the cap), lastly with the engine cool, remove the radiator cap and look in, coolant should be visible no more than half inch down the neck the cap is unscrewed from...

Is there signs of any dried coolant water marks under the bonnet? It is not uncommon for the plastic filler cap neck to crack/perish over time...

Check other fluid levels (brakes, power steering, transmission fluid), some pipe may be leaking onto something hot or even your air conditioning condensation/drip tube may have caused this if dripping onto the exhaust with air flow pushing it out the back of the car.

Have you had any work done on the car recently? Sometimes lubes and penetrating fluids over spray onto hot bits and burn off when moving....

If you are concerned your brakes may be binding, this is easy to check by feeling your alloy wheels after 15-20mins of driving, if one or two feel hotter to touch then that is normally the tell tale sign (sometimes you can "smell" the brakes burning which is not normal) - The back brakes/alloys hardly get used so should definately not be warm.

Usually a big problem has indicators - if you can't find anything, let a mechanic or Lex check it out, for your safety and others.

Let us know how you get on!

[rayaans]

Hi, I was driving my rx450h quite happily along the motorway and when joining a slip road suddenly noticed a huge amount of white smoke coming from the rear of the car. It lasted approx 1 minute or so as slowed the car down worried what this could be ? Has anyone had a similar occurrence ? having looked through the Internet it could be anything from condensation ( although I had been driving for over an hour at that stage ) to head gasket to overheated brakes ? Not sure but worried none the less. Any help or advice welcome. Thanks

http://www.networkautomotive.com/Smoke.html

The above link may be helpful. The good thing is that white smoke isnt too bad!

Bad news is it could be pretty much anything. The most common things would be engine burning the coolant. Check the coolant level and as above, generally check the fluid levels.

Too much oil can cause white smoke too

[Mapman]

Thanks for the replies. I have done the visual checks as advised and found the coolant level very low. Have looked as much as possible to see if any leaks but can't see any. I will top up and keep an eye on it daily. Engine oil is fine.

[ChrisKaye]

Hi,

Might be worth checking out how much a Lex extended warranty is from the Poole dealer and whether your car qualifies.

To lose a lot of coolant is worrying, at best you could have air in the system (and most likely will now depending if your coolant expansion bottle was empty and you have just refilled it) at worst you are looking at the beginning of a head gasket issue.

It is not uncommon for plastic components and rubber pipes to perish but at only 5 years old it seems unlikely. You may possibly have a leaking water pump or even a stone has put a hole in your radiator, try and park in the same spot and keep an eye open for drips on the ground.

Did you use Lexus/Toyota coolant when you topped it up?

[rayaans]

Hi,

Might be worth checking out how much a Lex extended warranty is from the Poole dealer and whether your car qualifies.

To lose a lot of coolant is worrying, at best you could have air in the system (and most likely will now depending if your coolant expansion bottle was empty and you have just refilled it) at worst you are looking at the beginning of a head gasket issue.

It is not uncommon for plastic components and rubber pipes to perish but at only 5 years old it seems unlikely. You may possibly have a leaking water pump or even a stone has put a hole in your radiator, try and park in the same spot and keep an eye open for drips on the ground.

Did you use Lexus/Toyota coolant when you topped it up?

Dont be alarmed if its a clear puddle though - thats probably the air con

Id be concerned if there is fluid dripping from underneath and if the colour is either pink or green!

[ColinBarber]

The loss of coolant combined with white smoke would point more towards head gasket rather than just a leak in the rad/water pump but I'd be surprised if there is actually a problem. The white smoke for example could just be from water formed in the rear silencer burning off as you went up/downhill on the slip road.

Keep an eye on the coolant to see if it drops. If you didn't know the level before the issue then you shouldn't assume it has suddenly dropped.

[Mapman]

I took my car to a local garage to have a test done on the head gasket and relieved when told that it was not losing coolant from there. They did road test it several times and heard a rattle as well as the white smoke/steam and advised I take it to Lexus to have them look at it as no warning lights coming on.

[ColinBarber]

Any chance you got some bad fuel with water mixed in it?

[Julius]

Hi guys, I have just noticed that I get white smoke from the exhaust during hard acceleration similar as above. The car drives great otherwise. I've checked all fluids and replaced pcv valve. I know this is an old thread but can someone please suggest as to what is happening.

Hi Mapman, any update about your issue please? Thanks.

[olliesgrandad]

I would suggest it is condensation as I have had this with my series 4 when it has been driven gently in town in cold weather. Give it some beans and a big cloud of white vapour. Don't forget for every gallon of petrol burnt a gallon of water is created.

 

[Illogan]

2 hours ago, olliesgrandad said:

I would suggest it is condensation as I have had this with my series 4 when it has been driven gently in town in cold weather. Give it some beans and a big cloud of white vapour. Don't forget for every gallon of petrol burnt a gallon of water is created.

 

I bet that's why it's (so often) raining over the M62!  😉

[Barry14UK]

Well done to have found a relevant post from several years back.  I am sure forum members would appreciate it if members who had problems reported back with what the answer/solution was.  This would help others with the same symptoms, as well be a courtesy to those who had tried to help with advice. 

Hope you get a definitive explanation/resolution Julius. 

[Mawil]

Hi

 

Did the problem stop? Im having similar.

[Ace8800]

I just noticed this on mine today.. 1st hard push from traffic light to get in next lane saw a massive puff of white smoke.. did get worried. Then did a 2nd push a quarter mile down the road and that was half the 1st puff.. 3rd was less then the 2nd.

I have full Lexus history, just had the big 80k last month, no leaks, fluids all good. I think its been driven softly all its life. I will give it some welly within reason and report back soon. 

[Ace8800]

Just a quick update, did a another cycle of the last and no smoke whatsoever. I think they just need a little push time to time to clear out the exhaust system.

[Barry14UK]

That's the best solution to a potential problem!  Thank you for your update

[scudney]

Probably just nothing more than condensation 

[DavidCM]

On 3/14/2023 at 11:12 PM, Ace8800 said:

 saw a massive puff of white smoke..

It could be the Vatican electing a new Pope..