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Hi, I'm new here and this is my first post. I'm working on a 04 Rx330 that has water pouring from what seems to be the rear of the forward cylinder head. I'm pretty certain the reason is the 25mm freeze, expansion, core plug I found lying in a lot of antifreeze just to the left of the thermostat housing, (see pic). Left when looking at the rear of the engine from the drivers side. I have not been able to get into it yet to find the place where the plug goes. I just wondered if anyone knew where that hole is and how hard it is to get to.
It's possible. I don't own the car, so i can't say for sure. I'm checking it out for a disabled lady we know. She said it had antifreeze in it and there was some on the engine. It had been down to 17 fahrenheit a few days earlier.
You state "water pouring out of engine", there should not be any water in the engine only coolant and should be very pink. If it is water you have issues, if there is only water instead of coolant in your cooling system you have issues...
I guess we're playing "you guys need to ask a lot of questions" today so I'll start... was the car left outside when it was well below zero degrees?
You state "water pouring out of engine", there should not be any water in the engine only coolant and should be very pink. If it is water you have issues, if there is only water instead of coolant in your cooling system you have issues...
I guess we're playing "you guys need to ask a lot of questions" today so I'll start... was the car left outside when it was well below zero degrees?
Water and antifreeze was pouring out as I added water. The freeze plug was lying in a pool of antifreeze. The car was outside on a night that went to 17 degrees, so not below zero. I don't know the strength of the coolant. I'm an ASE certified mechanic. I have never worked on this motor before. Nothing is visible as to the hole the coolant is coming from, and I'm just wanting to know where the hole for the freeze plug is and how much I might have to remove to get to it. I'll probably end up removing stuff till I see it. Thanks anyway.
If you internet search Toyota 3.3 engine freeze plugs or core plugs you will probably learn enough to take care of this problem.
AI says.
Replacing freeze plugs on a Toyota 3.3L (3MZ-FE) engine can be a complex job, as their location often requires removal of other engine components for access. There are multiple plugs located on the sides of the block, and sometimes one on the back near the transmission, which is particularly difficult to reach without engine removal
Thanks. I did do an extensive internet search and found nothing, except the same stuff you got from Google AI. I even got the factory service manual. It had nothing about the freeze plug location. Lack of information is the only reason I posted here at all. But I fixed the freeze plug yesterday. It's located on the rear of the head right behind the plastic thermostat housing/tube. The tube is something you don't often see from Toyota products, just a piece of crap. When I was getting the radiator hose off of it, a section of tube came with it. I could see that it had old cracks remaining in areas where it didn't break. A metal replacement should be here today.
So I had to remove the starter and a bracket and hoses, and unplug some harness connections to get the tube out and then the hole for the plug was pretty accessible. And I had already removed the air cleaner housing and some other stuff to get to the rest.
Last edited by Drp146; Dec 28, 2025 at 10:26 AM.
Reason: more info
Freeze plugs are not documented in fact Toyota doesn't even sell them as a separate part. You need to find out why the plug came out. Plastic cooling system components are garbage.
It's pretty evident that it either froze or has excessive cooling system pressure from a head gasket. I'll find out if it's the latter and get the answer. Too much water had already been added before I ever looked at the car, so my antifreeze tester wouldn't have told me anything useful. The color of the antifreeze was evident below the leak, so it had some, but the color isn't enough to know if it was good for 17 degrees, which is the coldest it has been here so far.
I'm very interested to see how this turns out. I've removed a freeze plug to install a block heater but don't think I've ever installed a freeze plug. Maybe I have and forgot.
I've installed a number of them. Most often because they corroded on older vehicles. Many times I used rubber expansion plugs, due to the finances of the owners. Removing a large amount of stuff to gain the access needed to put the oem type back in can be very expensive.
So I got the car running again, after getting the new metal thermostat cover and tube. Then water was leaking from the block heater plate, so i sealed that, and after if was running I saw the telltale leaky head gasket bubbles coming to the top of the radiator fill neck. It's not mixing water and oil and isn't puffing steam out the exhaust, so it's a good candidate for BlueDevil head gasket sealer. I've used it successfully several times before. in my experience, engines with these specific conditions are most likely to seal, I'll post the results of that.
So, after many delays, I used Blue Devil head gasket sealer, following the instructions exactly. It worked. The car is no longer losing coolant and running at normal temp. This is on a car that is worth less than the cost of replacing the head gaskets and having the heads milled. So in this case, it gave her a usable car. She bought this Lexus after her previous car was totaled in a wreck and she'll be getting a large settlement from that, when she can get something better. Hopefully this band-aid will hold till then. I've seen cars last over a year with this fix, but you never know.
Water is pouring from top rear of engine
