Coolant Loss

[Don33]

Hi, Lexi Fans. I have owned my 2002 LS since new and have no problems other than many mirror replacements. During my last oil change I noticed some dried pink coolant on some parts of the undercarriage. This led me to look at the overflow tank and discover that it was very low. I cleaned the exterior of the tank, added some water and marked the level. I drove 130 miles and checked the fluid and found that it had increased as expected. Twelve hours after parking, I checked it again and it was below the marked line. I repeated this with the same results. I have not found any evidence of leaking. I would appreciate your thoughts. Thanks

[someguy]

have you flushed your radiator recently? Maybe there's air in the cooling system. You might wanna put it on a ramp and run it to check for leaks.

[Don33]

Thanks for the reply. I had the cooling system flushed and new coolant added about 11 months ago. I checked the radiator and it was totally full.

[cappakazi]

I have a similar problem on the my old ls400, a mechanic told me there was a tiny leak and it dripped on to the exhaust manifold so it would dissapate before it hit the ground. Might be of some help to you.

[90LS400Lexus]

I have a similar problem on the my old ls400, a mechanic told me there was a tiny leak and it dripped on to the exhaust manifold so it would dissapate before it hit the ground. Might be of some help to you.

...and the cause of the leak was?

[lenore]

I had the same problem on my RX300 (1999) and it turned out to be a leak between the intake manifold and the cylinder heads. I had to remove the intake manifold to resolve it. The pink dried material was hard to locate on the intake manifold as it is buried on the 1MZE engine. I am not sure on your LS... good luck.

[Don33]

Thanks for the replies. Sometimes good comes out of bad and in this case when I put the car up on the ramps yesterday for a really close look with the engine covers off, I found that the transmission oil pan is seeping. Since my extended warranty is up at the end of October I’ll monitor the coolant a bit longer and then may have to have both repaired.

[vroom8]

also check the ported vaccuum switch- mine was leaking around that....just enuf to have to fill the reservior <some> every week or so.

[Don33]

Thanks. What [1] does the switch do? [2] what does it look like? [3] where do I find it?

[vroom8]

Thanks. What [1] does the switch do? [2] what does it look like? [3] where do I find it?

vaccuum switch- this side of Lexus moto on engine- might have to remove some plastic to see it.

[Don33]

Thanks to all who responded. In the past week, the coolant level has remained stable. I'm driving I-10 from the ocean to the Arizona border and then north to Nv. on Monday. So...we'll give it a good test then.