Coolant change and new T's about 9 months and 10k miles ago, new timing belt and water pump 30k miles ago. Current mileage 130k. 9 months and 10k miles ago coolant in the reservoir was at the full line after change. Within a coupe of months level went down about 1 1/2 inches from the full line and stayed there until last night. Smiled burn't water smell when I got home checked level and it was the same 1 1/2 inch below full. Checked this morning and level dropped 4 inches to about 2 inches above the bottom of the reservoir. No visible leaks or indication of a leak. Oil level is perfect and oil looks good. Now before I had the coolant changed 10k miles ago, the level in the reservoir always ran about 2 inches above the bottom of the reservoir. All I've done at this point is this morning I filled the reservoir up to the full line. Suggestions for what my next steps should be?
Coolant level in reservoir keeps getting lower?
- Thread starter SWUtah
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I'd start looking around for a leak in the front and rear of the engine compartment if you think it might be leaking. If it's in fact leaking that much, you should be able to spot the pink crust. The level in my reservoir fluctuates, but I just take a look around whenever I fill up gas and make sure there is at least some coolant in the reservoir.
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- #3
I got in there and looked at all the hose connections with a flash light and can not find any indication of a leak. I keep my engine and engine compartment clean but have not needed to wash it for 6 months so if any pink crust it should show up? Would a pressure test be the way to go?
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- #4
OK after topping the reservoir off I drove around 60 miles, no hot smell and no coolant lose. Guess the beast is self healing or it was a air bubble caused by indigestion from eating a Jeep Wrangler 
I'd do a cooling system pressure test...some auto parts stores will give you the tool for a day or 2.OK after topping the reservoir off I drove around 60 miles, no hot smell and no coolant lose. Guess the beast is self healing or it was a air bubble caused by indigestion from eating a Jeep Wrangler
Coolant leaks are typically not "self-healing"...I was bitten in the butt by thinking that about the thermostat housing on my LX. ;(
After a coolant change, I see a bit of up-and-down happening with the reservoir tank...level usually stabilizes after 2 or 3 cold-hot-cold cycles.
hth
Steve
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I'm very interested in this. I would be extremely worried about this if I were you. I would highly recommend a pressure test, and a combustion leak test. It takes 30 minutes to do both of them and it can easily save you from a new engine. You Toyota guys don't have to deal with cooling system/head gasket problems on modern engines, and it is easy to blow them off until it is too late. Your problem sounds like a perfect example of a head gasket to me. Coolant in oil is not that common with modern engines and head gasket material when they lose their head gaskets. Combustion leak is far more common and the test will tell you 99% of the time. Coolant likes to disappear so it is very hard to tell with an incredibly slow leak like this just by looking under the hood.
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- #7
Oil looks great and is right on the mark level wise. If it was head gasket leak oil would be contaminated and milky? Right?
I had the same thing happen to me a few months back, and eventually I was able to spot the leaks around the seams in the radiator. I replaced the radiator with a new OEM one and it's been good since. Mine is a 1998 however, so at that point I think the failure was as much related to age than miles since I only had around 125k on it then.
You smelled coolant around the first time you noticed level drop? That implies an external leak somewhere. Pressure test. Don't forget the rear heater core/connections if yours has this option.
Some burping after coolant change is normal, as is some slow evaporation from overflow bottle, but yours doesn't sound like either of those.
Some burping after coolant change is normal, as is some slow evaporation from overflow bottle, but yours doesn't sound like either of those.
I had an incredibly intermittent leak from the little hoses on the bypass line on the front of the engine. Seemed like it only leaked on my driveway. ..
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- #11
The burnt smell did not come from the engine compartment more like the middle of the 100? I have not used my rear air until the last couple of months. Anyway there could of been a bubble back there? From when I parked it that night in the garage until I checked the reservoir the next morning the level in the reservoir dropped 4-5 inches. When I opened up the radiator cap the next morning when it was cool the radiator was full. Oil color and level was perfect. When I started it no white smoke or any smoke. I filled the reservoir back up to the full mark and it has not moved, in two days of driving. I will get it pressure checked at my next oil change or sooner if it gets weird again before my next oil change. I am also putting on a new radiator cap and over flow cap. If any further fluid loss then the pressure test, also next oil change I will get an oil analysis, even if no further fluid loss.
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With the 2UZ-fe there would actually be a pretty small chance it would show up in the oil. Most likely the coolant is being evaporated by combustion gas exposure when the heat distribution in the head happens to be configured in a certain way.(that is, assuming you do have a head gasket leak, which you might not) the combustion gas test costs 0 dollars to rent from O'reilly and it is the definitive test. It is a very easy and safe test.
IMPORTANT:
be sure the car is completely cold before taking the cap off!!!!!!!
and the part about squeezing the coolant out with a turkey baster probably wont be necessary for you since you're losing so much coolant(it will probably be low enough in the first place)
I would let the car get to operating temp before ending the test but go ahead and keep squeezing the little squeeze ball periodically all the way through warm up, because you never know when certain things are going to expand and contract and allow the leak.
Crap didn't mean to hit enter, also REMEMBER TO TAKE THE CAP OFF BEFORE YOU TURN THE CAR ON, AND BE SURE TO PUT THE CAP BACK ON BEFORE YOU TURN THE CAR OFF. Pressure builds up in the system as the car warms up (fluid expands well under heat, thats what causes the pressure, and thats why radiator cap has a little spring on it, it is a pressure relief valve) this pressure is nessecary because without pressure water and ethylene glycol would boil at much lower temperatures(look at thermodynamic tables if you're really bored, but it is somewhat interesting) A sudden loss of this pressure (i.e. taking cap off) would cause tons of steam in your face. and if you turned the car off with the cap off, the fluid would stop cycling through radiator, temp would spike and it would go in your face
Hopefully your is not this but our LX did this once and seemed to resolve itself. Did not think much of it but when the timing belt was done later on it became pretty apparent where the coolant went. The water pump was covered in dry crusty coolant as the weep hole seemed to have been leaking at some point. Yours is relatively new but failures do happen.
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- #15
So how many miles between the coolant episode and when you did the new timing belt and water pump and discovered the water pump weeping problem?
Would a pressure test of the system reveal a water pump issue? Just curious as I found what appeared to be coolant in a small puddle in the garage about 4 months ago. Took to dealer and they did a pressure test on the system with no leaks detected. Have driven about 2500+ miles since then and do not appear to have a problem.
Unknown to us ours was way overdue. Was at probably 130k when it happened. With yours it seems unlikely with such low mileage but just something to keep in mind if you cannot track it down to any other source. Was it an oem pump or after market?
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- #18
Water pump and timing belt done at Lexus dealership by original owner at 98,000 miles. I had coolant changed again at 122,000 miles when I had the T's replaced at the rear of the engine. I've now driven a couple of hundred miles since the episode and no change in coolant level no sign of leak. I'm putting on a new Lexus radiator cap and over flow container cap tomorrow. If I see any more loss of coolant after that it goes in to the dealer for pressure check, etc. etc.
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- #19
Put on new radiator cap OEM and a new over flow tank cap OEM. So far no fluid loss since initial loss. I will keep a close watch on it, if any more loss in fluid then I will take it in for pressure test to locate problem.
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- #20
Leak was from the main hose coming out of the bottom of Raditior, replacing both top and bottom. 9 year old truck with 130k miles that lived its life in the desert which is great for lack of rust but hard on rubber. Thanks for the help.