1990 Lexus LS400 Q&A
1990 Lexus LS400 Question: what part need replacement
I have seen the steering high pressure hose leak (deteriorates over time because of heat in the engine compartment). I have seen the seal between the Power steering resivior and pump fail and the pump itself to fail and leak. There is a black plastic switch mounted on the Power Steering Pump (with two rubber vacuum hoses on it) that allows the engine idle speed to be automatically raised when you crank the steering wheel while parking, if that switch failed power steering fluid could be drawn into the engine and burned in the engine. With the engine turned off disconnect those two small diameter vacuum hoses (they just pull off), see if there is oil inside the hoses. Start the engine and see if you can spot a leak while you get a friend to turn the steering wheel from side to side (ensure the fluid level is full but not over full). You will have to wash down the engine and area of the power steering pump first to pin point the source of the leak before just replacing parts in hopes of fixing the leak. A repair shop will often wash down the engine and add dye to the steering fluid that will show up under a black light. Are you sure it is power steering fluid that is being burned ny the engine? Could you have a power steering leak and an engine that has worn valve guides or rings and is actually burning engine and not power steering fluid. I have seen valve guide wear on high mileage LS400s that puff a large cloud of smoke when the engine is first started. - patrick mannion
I have the same problem with my 1991 LS400.. Never had smoke come out the tail pipes till I found out my power steering kept running out of fluid, but I could find Not 1 drop of fluid under the car, till I stopped putting fluid in it, after a day or 2, it stopped Smoking, Good!!! for a minute there I thought my engine was about to go. Not the case. It was the the High presure line leaking into Vacuum line switch from power steering burning out the exhaust. - phewjr
http://www.lexls.com/tutorials/steering/pspumpremoval.html here is a web site that tells you what causes your lexus to burn power steering....i did it and i now dont need to add power steering fluid... - Visitor
there is a valve below the powersteering pump which is there for allowing extra air from intake pipe to intake manifold. this valve is faulty and oil is leaked into. and get carried into manifold.the part is expensive.beter to get secondhand powersteering set. - Visitor
i had the same problem you have, i was putting power stering fluid im my lex every 24 hours get the power stering vacum censor in the lexus dealer it cost $145 an your problem will be fix - Visitor
My car is doing the same thing after i spent 2500 dollars in trying to fix the problem, plus fixing the hose i found out it's the steering rack, or what u call the rack and pinion assembly its about 800 total to fix and no more smoke...... - Visitor
My cars water level is normal with no change, and I have not observed any leaks, but my car has stated to run warmer than normal. I turned on the heater to avoid it over-heating. I have not allowe...
I have a 1996 lexus ls400 and when im driving and touch the brakes, it sways back and forth like a fish in the water trying to swim. the fron suspension is worn out but i do not think the shocks wo...
my power steering fluid needs to be replaced weekly, and i get a blue/white smoke on start up.
fuel gauge doesnt work replaced sending unit and still doesnt