2010 rx450h white cloud on acceleration

Mawil · January 25, 2023

Fully Lexus serviced 2010 rx450h. After about 30 mins in rush hour traffic joined a dual carriageway and gave the engine some beans. HUGE amount of white vapour came out the back, so much so the car behind, about 15 feet behind, completely disappeared in it (briefly).

I have noticed on colder days a really embarassing amount of vapour came out the exhaust but gave it no thought until today when to be quite frank it was dangerous for the car behind.

It was a cold day again, about 1 deg, but the engine was very warm and not a single other car was emitting anything like that much.

Any ideas? Is this a common feature of the car that nobody told talks about? I usually find these things out after its too late.

royoftherovers · January 25, 2023

31 minutes ago, Mawil said:

Fully Lexus serviced 2010 rx450h. After about 30 mins in rush hour traffic joined a dual carriageway and gave the engine some beans. HUGE amount of white vapour came out the back, so much so the car behind, about 15 feet behind, completely disappeared in it (briefly).

I have noticed on colder days a really embarassing amount of vapour came out the exhaust but gave it no thought until today when to be quite frank it was dangerous for the car behind.

It was a cold day again, about 1 deg, but the engine was very warm and not a single other car was emitting anything like that much.

Any ideas? Is this a common feature of the car that nobody told talks about? I usually find these things out after its too late.

If you have not had the vehicle for more than 6 months and you bought it from a Motor Dealer Mawil, then take it back and ask him to fix it as the Law requires. Consumer Rights Act 2015.

Spock66 · January 25, 2023

4 hours ago, Mawil said:

Any ideas? Is this a common feature of the car that nobody told talks about? I usually find these things out after its too late.

White smoke is usually a sign of water vapour, could be the head gasket.

Check the oil level and filler cap for any signs of water or white emulsion.

Barry14UK · January 25, 2023

Head gasket my thought too. What's the mileage?

MRx450h · January 25, 2023

4 hours ago, Barry14UK said:

Head gasket my thought too. What's the mileage?

135k. F Lexus SH. Had the big service last August. I know in the weather we are having condensation is a thing but in many decades of driving I've never lost sight of the car behind me. It's a huge amount really. It certainly has the look of water vapour rather than smoke, bit still....

MRx450h · January 25, 2023

8 hours ago, royoftherovers said:

If you have not had the vehicle for more than 6 months and you bought it from a Motor Dealer Mawil, then take it back and ask him to fix it as the Law requires. Consumer Rights Act 2015.

Thanks. Will bear that in mind. I'm quite a long way from the dealer though which is a annoying.

Barry14UK · January 25, 2023

I had a cylinder head gasket fail on a V6 Camry I had many years ago at about your mileage. In my case the the coolant was being forced back to the external tank and out as could be easily seen. Incidentally, the resultant overheating caused baked on oil residue to flake off and gather in the sump. This caused the oil strainer to block up and oil warning light to come on, so sump removed, strainer unblocked and system flushed as a secondary exercise. Sincerely hope your problem is not so involved.

You could monitor amount of coolant loss which should not be great and ask Lexus what they would expect in your car. Alternatively, if you have breakdown cover, you could get an opinion that way. Certainly, worth investigating before making precipitous work.