nervekiler

hey guys let me FIRST say that i spent the better part of this morning searching the forums and working on my car. actually since 11am and its almost 3pm now. i still havent found what i need so im asking in this thread. please do not tell me to search unless you have links to the threads you are referencing becuase, like i said, i've searched for a long time already.

so this morning i have already R&Red the throttle body to clean it. i noticed that there was NO coolant in the line that passes through the TB. i also replaced the coolant temp sensor and did notice there was coolant underneath the sensor when i replaced it.

syptoms im experiencing.. heater does not seem to blow as hot as i woudl expect it to. i can sometimes hear water bubbles in the heatercore although this happens very rarely. the engine throws a CEL and the code says she runs lean also accompanied by a choppy idle (reasons for working on it this morning). not sure if its related.
the coolant res. seems to not get warm. the coolant stays cold.

now i took the bleeder off of the thermostat housing to look inside and i can see coolant. i figured maybe there is a plug in the line between the engine to the coolant res. so i put my mouth to the top of the res, covered the overlow tube with the finger, and blew air into it to verify it wasnt clogged. coolant came out of the bleeder thermostat area so i can verify its not clogged to the res.

so i tried to bleed the system before i started the car for the first time today. when the Tstat is closed to noticed that when i loosen the bleeder, coolant seeps out. after the Tstat opened (and the air moving through the radiator became warm showing there is coolant in the radiator) i opened the bleeder and there is no coolant seeping out. so i removed it completely and can verify that the pump is pumping coolant. i see a nice stream flowing through this area. now i think something maybe wrong because i would assume that once the Tstat opens, and i open the bleeder that coolant should leak out once the air pocket works itself out of the system. is this correct? it only leaked when the engine was cold before the Tstat opened, but not after.

i massaged my radiator hoses while the engine was running and this seems to put pressure underneath myslightly cracked bleeder bolt because i can see it moving BUT it does not leak coolant out unless i remove it completely (showing very low pressure built up?).
while squeezing the radiator hoses i can also hear coolant (maybe partly airbubbles too) moving around and it sounds like its moving around inside the resevior but the res. coolant remains lukewarm.

now i have not removed or replaced the Tstat. i havent taken the cover off to verify it is there but i assume its there because of the difference in the bleeder once the vehicle warms up.

so my question is i need to verify the correct way to bleed the system. alsoshould my res. coolant be as hot as the coolant in the engine? the res is overfull.. in fact the res level seems to have gone UP even after my attempts to purge the air from the system. did i somehow induce more air into the system by loosening the bleeder while the engine was running? i would assume the coolant level would go down (also the car warmed up woudl that be why the level went up?).

im confused as i do not understand this system completly and i dont understand how to bleed it completely.
all the searches provided was confusion of different bleed methods for different year LS's and different lexuses all together. also putting ideas in my head that my Tstat, waterpump, hetercore, and/or radiator are all failing (which i hope, by the tests and results listed prove or disprove any of those statements).


so anyone able to shed some light on my field tests?

thanks for your time and expertise.

-frank

Amskeptic

The biggest issue with filling/bleeding a system has to do with fluid expansion. Within minutes of starting the engine, the heads get hot and coolant expands and even boils around the exhaust seats. This expansion mimics a system being "full" as it sprays coolant out of bleeder ports and expansion tanks. Meanwhile, you have a thermostat that is going to open soon and drop the level in the expansion reservoir. Gets confusing.

Do the below if you are doing a system fill:
Stone cold engine. Leave it off.
Put coolant in the expansion reservoir past the full mark. Milk the hoses and refill expansion reservoir as necessary. You get some engine filling at the very top of the expansion reservoir, so don't be shy.
Fill the engine dead-cold through the bleeder screw. It is annoying and slow. The last 1/16" before it overflows seems to be the only place it will drink. Eventually you will note that it is truly full. Now fill the expansion tank to the full mark. Cap on.
Start engine. Turn heater up to 85, floor and defrost and sunroof open. Rev the engine to 2,000 to 3,000 rpm after just a few minutes of warming up. Run it up and down and blast a couple of 4,000 rpms after the engine has begun to throw a little heat from the vents. Don't be shy, this is critical for blasting air bubbles out of the heater core and the heads and the throttle body loop, and you need to do this NOW before the engine gets too warm. Shut it off. Slowly release expansion reservoir cap and fill to full. Repeat above. Now drive it normally for the rest of the day. Park level at the end of the day.
Next morning, do not be surprised to see the level in the expansion reservoir way down. That is the way this bleeding/fluid expansion works. Fill to full mark, but not more. Check again the next day.
Colin

nervekiler

thank you colin i did not realize that i would need to drive it.

so u didnt mention using the "bleeder" screw on top of the Tstat housing at all except for initially filling up the system?
i was confused about that part becuase on my 1995 camaro i was required to bleed it after swapping out the radiator.

i'll keep an eye on the level after i drive it to work today and make sure its at an appropriate level before i drive home.

so it bleeds itself pretty cool.
will overfilling the coolant reservoir hurt anything or will it just eventually overflow and leak onto the ground?
mine has been overfull for as long as i can remember. hasnt seemed to hurt anythign but what do i know my car hasnt ran "correctly" since the first day i got it.

Amskeptic

It is a good idea to crack that bleeder bolt loose when you are initially filling system through the expansion reservoir, yes. It is next to worthless once the engine is warm, and in fact will work against you.

If the reservoir is overfull at your stone cold morning check, lower it. The air inside the reservoir at the correct level is an important element in allowing the system to expand the coolant without leaking. This reservoir is designed to not allow that air to enter into circulation. As you may know, people have leaky reservoirs and coolant level sensors enough as it is with these cars. You will see the level marks all over these engines with warm and cold positions. Follow them.
Colin

curiosul

As you can see from my earlier posts, I'm just a potential owner so I don't know too much about this particular car but I'd like to share my experience. This worked perfect on a 98 civic and on a 96 TL 3.2.

Find a steep hill or anything that can incline the car SAFELY at about 10-15 degrees or more and park it SAFELY with the front up. Make sure the engine is not hot; it can be warm though. Open the reservoir, fill it close to the max (the "max" marking ...). Open the radiator cap. if you can't see the fluid level, pour some in but don't get too close to the brim. Start the engine, turn on the heat to the max and wait for the thermostat to open (you'll notice fluid either moving in the radiator or even disappearing from it). as soon as you see the fluid level going down or bubbles showing up, start pouring liquid BUT NEVER to close to the brim (at some point the liquid will start expanding and you'll make a mess). Rev the engine a few times to make sure most if not all the air pockets are purged from the system. As soon as there are no more bubbles showing up, turn off the engine, put the radiator cap back on and (optional) repeat the same thing next day (after the engine cooled down significantly).

I hope this helps.

Amskeptic

That incline stuff is not really relevant with the Lexus V8. The coolant bottle is to the left of the engine and it is pretty much the high spot. You park the car on a hill and you are asking for trapped air in the radiator, there is no radiator cap . . . . . . . . . . . . . . . .
Colin

curiosul

my bad ...

bacaudio

I had this problem with the heat sometimes working and sometimes not. What I did was stick a garden hose in the upper radiator. (after I drained the coolant) and I took off the outlet side off of the heater core. Flush it all out till it is clean water. Make sure that the heater water valve is open. I believe up was open you may have to verify that. After the system is flushed put in antifreeze. Make it a little stronger than 50/50 since there is going to be water in the system. You can also do it this way here: http://www.lexls.com/tutorials/cooling/coolant.html
but I found that flushing it with a garden hose worked best for me.