Wwhite Smoke When Cold Starting

[Birchall]

Hi,

I have a strange problem with my imported LS400.

I have two separate problems that look very expensive but I was wondering if there is anything that could connect the two (It might be something unique to a Lexus)

The car puts out a huge white smoke screen when started from cold ( the longer it is left the worse it is). I would normally assume that this was due to worn valve guides or the like, but this is normally a bluer smoke. It also smells more like burning transmission/steering fluid than engine oil.

I am also suffering from a major loss of power steering fluid. It uses around a litre in a week. The strange thing is that there is no sign of the leak on the floor even though the car is parked in the same place every day.

Is there any possibility of a connection between the too. If it had been any other car I wouldn't even ask the question but a Lexus (especially an import) could have some kind of "pollution control" that burns any excess or leaky fluid?

It is a very long shot but can anyone indicate if there could be a connection?/

Thanks

Steve Birchall

[Birchall]

Hi,

I guessed right.

Strangely enough the smoke was being generated from the power steering fluid being sucked up into the air box through the special vacuum pipes that are fitted to the power steering pump. I temporarily bypassed them and the smoke disappeared and the power steering fluid no longer disappears. I will replace the pressure switch that they are connected to and that should solve the problem permanently.

So if you are having clouds of smoke when starting the car don't replace the engine, check the vacuum pipes on the steering pump first, it could save thousands.

Cheers

Steve Birchall

[den]

Hi,

I think I may have a similar problem,loosing power steering fluid and white smoke .My mechanic had a quick look and spotted pipes to airbox but didnt find pressure switch you mentioned,so if you could point me in the right direction it would be much appreciated cheers.Den

[Birchall]

Hi,

I didn't do the work myself but the switch is in the power steering pump (at the back of it where the two vacuum pipes are connected).

If you want to check to make sure that this is the problem then temporarily disconnect the two vacuum pipes at the manifold and join them together with a tube and blank off the two pipe connectors (one on the manifold in the middle and one on the intake pipe). This should stop the smoke and possibly reduce the fluid loss but be careful the fluid will have to go somewhere and the pressure will force the pipes apart if you are not careful and you will get fluid over your engine bay and more seriously, your brake discs, so just try this out to confirm that it stops the smoke and the fluid loss and then reconnect them properly until you get the switch repaired.

But don't run too long without the repair because the burning of the fluid will damage your catalitic converter.

Good luck

Steve Birchall

[den]

Thanks for advice mate it has been most useful,cheers den

[Pyrex]

An excellent piece. It is always interesting to learn querky faults.

Just a mention, in case some readers get up tight about white smoke on cold mornings for nothing.

A well tuned car, and especially one like the LS with a large capacity engine can and will throw out large volumes of steam from the exhaust on cold mornings, it is quite normal, and is a by product of the combustion process.

I have been flagged down by a motorist when mine was pumping out steam on one occasion. Great billowing clouds of the stuff, but unlike the fault mentioned, there was no smell of burning oil, and it dissapeared quickly, unlike oil smoke which would hang around after the car has moved off.

:mat: