LimpnLexus

Hello,

New to the forum and put my first post in the introduction sticky. I have a nice running ES330 for the first 10-15 min. and then she turns nasty on me. I picked up the car as a project car and found the previous owner had neglected it.

Right now it overheats and boils into the overflow tank/reservoir. I'll try and be as descriptive as I can. When first starting, the car runs fine. Temperature gauge climbs to mid point and she moves along nicely. At some point the overflow tank begins to gain coolant. Cooling fans intermittently come on and shut off. I can turn the heater on, blast hot air and get the same result. I can put on the A/C and get the same result. Both upper hose and lower hose are hot and the system is pressurized. I changed the thermostat and took out the green coolant the previous owner had put in.

Now the coolant will continue to enter the reservoir tank until it spits out the purge cap. Inside the tank you can see the coolant bubbling and gurgling. Mind you the fans are going on AND off. What I'm not sure of is if there are different speeds for the fans and if they should stay on longer to keep the coolant from bubbling to a boiling point.

I've performed a block test to check for a blown head gasket. Dye stays blue. I've changed the radiator sensor (low on the passenger side) - no change. I've changed relays around in the fuse box - no change. I've changed the sensor by the cap - no change. I did all these sensor changes to see if the fans will come on sooner or kick into a higher speed. I'm also surprised that the fans won't stay on even if you shut the car off. They will run with the key in the accessory position, but not off.

So I'm starting to think it's the water pump. I don't know if it has ever been changed and I was checking off the cheaper things first. It seems to be pushing fluid around, but inconclusive. Some threads I've read elsewhere have the same symptoms, however the original poster never comes back to say what they may have found and how their issue may have been solved. Very frustrating.

There was a .PDF by a member regarding what to do with unplugging fan connectors and checking ETC's, but I don't know if that'll help. I know the next steps will be the costly ones. Hoping for a simple solution like "Yeah that happened to me and this is what it was" type thing. Thank you in advance.

LeX2K

It's unusual for the water pump impeller to fail but it does happen or in extreme cases it disintegrates due to old coolant. I would get a Lisle spill free funnel and run the engine with that if the coolant still boils then either the coolant is not circulating or exhaust gases are being pushed into the cooing system. Are you sure the thermostat is good? Was it installed with the jiggle valve at the highest point?

LimpnLexus

Thank you for responding. I installed the jiggle valve at TDC. The thermostat is new, however I do know they can be bad out the box. It seems all the bubbles come out and I fill it until there is no more room. I don't have a Lisle spill free funnel, however I do have a funnel that fits in the opening pretty well and I'll let the car run watching the whole time until the bubbles stop.

Another thing I noticed...when the car is running the bubbles come out. When I shut the car off the coolant heaves up in the funnel like a mini eruption. When I turn the car back on, the coolant sucks back into the engine, but it'll then re-enter the funnel.

LeX2K

Did the car over heat before you replaced the t-stat? OEM 'stat I've never seen bad out of the box. On block testers they are not reliable in my experience if you really want to know if you have a HG issue pressurize a few cylinders using a compressor.

LimpnLexus

Yes...so far everything I've thrown at it hasn't changed a thing. The unknowns right now are the radiator cap (I don't know the correct atmospheric rating for this car or how old the cap is), cylinder compression test, and water pump condition. I'm having trouble uploading pictures and videos since my computer is slow today.

LimpnLexus

Temperature gauge where it should be for 15-20 minutes before overheating.

Block down leak test after 2 minutes.

Where everything erupts. Pressure is so high at this point and temperature gauge is climbing.

Pouring out of the top.

Cooling fans running albeit one speed.
Trying to add some pictures of the issues I’m having.

LeX2K

What do you meant the pressure is so high? How do you know? Either way you need to do further testing get an adapter so you can pressurize the cylinders, pull the water pump or both. Or at least get a cooling system pressure tester. FYI if you run the engine without the radiator cap (yea I know it's not on the radiator) it should not boil over.

LimpnLexus

Correct...if I run the car without the cap it doesn’t boil over or fill the overflow tank. I don’t have a compression tester so I’ll have to get that. I was able to do a pressure test on the system and pump it up to 15psi (which is about equivalent to 1.0 atmospheric pressure stamped in the cap). It held until I released the pressure.

In regards to the pressure being high, when I start the car both hoses are squeezable. It’s like that when idling until the thermostat opens. Then the hoses get real hard, both upper and lower.

That’s when the reservoir starts to fill...and fill...and fill until it spews out. Then let the car sit for a few minutes and I can squeeze both hoses again. I can even take the “radiator” cap
off...lol.

LimpnLexus

New wrinkle to my dilemma. As the car has been cooling down both upper and lower radiator hoses have collapsed. I searched the forum for this topic and most responses were to get a new radiator cap. I'm going to order one (Lexus OEM) and both hoses. Hopefully this will take care of the issue...fingers crossed!

Tootsall

Not that unusual: when the engine shuts off the water pump stops circulating and the heat in the block soaks into the coolant fluid which causes it to further expand until the block starts to cool down.



If the level in the overflow bottle does not appreciably drop on cool down and as the rad/engine hoses collapse, something is preventing fluid from returning to the block from the rad. Could be the bad rad cap or a blocked tube between the rad and the overflow bottle. Has the overflow bottle been cleaned out or is there a bunch of junk in the bottom of it? Might be worth just replacing the tubes from the rad to the overflow bottle cap and the one from the cap down into the overflow bottle and making sure the connecting ports at the rad and the overflow bottle cap (and down into the tank) are clear. From your fourth picture down, it looks to me like coolant is not getting from the bottle cap down into the bottle but is blowing off through the vacuum/pressure relief port; there is still space in the bottle so that's where I'd start looking.

LeX2K

From the sounds of it this will solve your problem. And I should have asked initially if the engine overheats with the rad cap off, to be clear your engine is not over heating what is happening is coolant (or most any liquid) expands when heated the job of the rad cap is to allow coolant into the overflow until the engine is warm. If this doesn't happen pressure builds up then a safety valve in the cap releases and pressure is quickly released. This will cause the coolant to instantly boil because of pressure drop.

As suggested also check the tubes to make sure they are not blocked.

LimpnLexus

Thank you for your replies Tootsall and Lexus 2000. I have cleaned the reservoir tank out. What is odd is coolant will go from the radiator to the reservoir tank. I can start the car cold with coolant just above the "L" and it'll be brimming and brewing within 20 minutes. So it's going in, but not coming back to the radiator. Sorry...in the fourth picture, I actually had just water in the system at the time because the previous owner had green coolant in it. I was flushing it out. The reservoir in that 4th picture is actually full of water. When I thought I had all the green stuff out I put the red coolant in (mixed it 50/50) and was hoping it would make the car run cooler, but it was still pushing it out.

I will also check the hoses from the cap to the reservoir tank and the one going down into the tank.

One thing to mention. In the 4th picture I had the old cap on the reservoir tank. It would pop off under the pressure it was experiencing and the loss of coolant was pretty explosive. Since then, I replaced it with another cap that fits tighter and the vent is at a 90 degree where the old cap was 180 degree. I'm not sure if that can also be an issue

LeX2K

That reservoir cap needs the inlet and vent in the correct orientation there is a check valve in it. The replacement you got might be a slightly different design either way it needs to have the hose on the correct end.

Tootsall

Ahh, well with that additional info, I still think there is something in the overflow system (cap, tubes), that is acting like a one-way valve and not allowing the return of coolant to the rad from the bottle. Something you may not have replaced...maybe the tubing? Blowing the old cap off the bottle is a symptom, not the cause. The rad cap was allowing the bottle to pressurize. I’d bet that overflow system has still got junk in it somewhere.

LimpnLexus

Ok...sorry I didn't answer your thought on this Lexus2000. The car does overheat when given the chance by leaving the cap on. When off it does not overheat. The operation of the cooling system as you describe makes sense. Possibly the radiator cap is not allowing the coolant to enter the reservoir tank while warming up. The reservoir tank will stay stagnant with little bubbles coming through the down tube. Then it will start to fill as the system becomes more pressurized until it fills the reservoir up to the top and coolant spits out the vent in the cap.

What it seems to be doing is pressurizing and it doesn't stop until it pushes everything out the reservoir tank. When I shut the car off for a few minutes, there is no more pressure in the system and I can remove the radiator cap without fear of getting sprayed.