stoked

iTrader: (1)

my LS has begun to eat coolant, there is no leak, i dont know where it goes, i replaced the thermostat, it eats up the coolant and then the temp needle starts to head up to over heat, but i stop in time, also sometimes, it registers its overheating, but in actuality it seems like its not?

GA400

stoked,

check your oil. does it look ok? if it looks like you have some water in it, you may have a head gasket problem.

good luck,

GA400

stoked

iTrader: (1)

checked the oil and it looks great, no water or milky look, all oil? anything else?

GA400

hmmmmm......it is going somewhere. Can you park it in the same spot every day and look for spots? Your factory coolant should be a pink/red color but it may have been switched to a green type (non-toyota). there are a few different stop leak products, some with a dye to help detect leaks. Have you tried running the heater to force it to flow through the heater core? Check the passenger floorboard after running the heater - it may leak in there if it has a leak (never seen it do that on lexus but have on several other cars) On the front of your engine is the water pump - it is in the path of the accessory belt - look down there with a flashlight at the weep hole - is it oozing or leaking coolant? That indicates a water pump problem if there is. Anybody else have any advice for stoked?

GA400

2UX31 YM

I developed a slight coolant leak and my accessory belt was squeaking. Turns out it was the thermostat gasket. I replaced the belt anyways but when that gasket gets worn out, the coolant leaks out the front of the motor and dries or gets blown aroung in the engine bay. Its a long shot but I had the same problem because it doesnt leave a mark on the driveway to pinpoint the leak.

I have a 1993 ls400 with 141K

wwest

Get out on the highway and warm the engine up thoroughly and now at about sixty-per put the gear shifter in second and get off the gas.

Look behind to see if you are trailing a slight or heavy cloud of steam.

With the throttle closed and the engine being "driven" (over-driven in second) with the roadbed traction there will be LOTS of vacuum in the intake manifold. In which case if you have a head gasket leak the engine coolant will be SUCKED into the combustion chamber resulting in steam out the tailpipe.

Good luck.

healerhand

Check the Radiator Fan and plugs. A lot of time if the fan or wire/plug is bad, the car will over heat.

david

stoked

iTrader: (1)

well i changed the thermostat and put on a new gasket and have had no problems for a week, very nice. also is the SC400 transmisson supposed to shift as smooth as the LS 400? i think my SC is a little lurchy/jumpy, im thinking maybe a motor mount or something?

GA400

you changed the fluid recently? many people here have reported a flush with the T-IV transmission fluid fixes problems. My LS400 is shifting much smoother since I had mine totally flushed and the filter replaced.

GA400

stoked

iTrader: (1)

car has 99k, had full transmisson flush and rear diff service at lexus at 86k miles

Pilot

My 91 LS400 did the same thing, and it ended up being the water pump. It was not leaking on the ground, but only showed up when I was having the timing belt changed. The water pump is not visible until you remove the engine front cover. You could see the mineral deposits trickling down on the lower part of the water pump, which was caused from a slow leak. I had a new OEM water pump installed and the water quit going down.
I would highly recommend that anyone who is changing the timing belt, to also change all 3 engine oil seals located on the front of the engine. There is one for each overhead cam, and one for crankshaft. They only cost a few bucks each, and will save you from any oil leaks down the road. I watched my mechanic change all three in less than 15 minutes!
I changed my water pump, timing belt and all 3 oil seals, all at the same time.

Pilot

mtnandy

Well my wife just told me her feet were all wet and guess what ! The heater core must be leaking. I found coolant all over the floorboard in the passenger side. I am affraid that the core must have a leak in it. Anyone know how to change it out. I took part of the dash out but can,t ssem to get to the core.