Is this the Engine Block Coolant Drain Plug?

That does not look like the engine coolant drain cock from what I remember. It is close to an electrical connector and bracket but I do not remember it being underneath the bracket as it appears in this picture.

IIRC, it was to the left of the bracket and about half way up the engine block. To tell y ou the truth though, I would have to look for it again before I could tell you for sure. It was pretty obvious that it was a drain cock once I found it.

 

I wanted to say that I thought the drain cock was bronze and that it was a hex key socket head and not a bolt head, but I was not sure enough to say so. The above picture is exactly what I remember. I remembered that once I saw it that I was sure it was the drain cock.

I remember it being to the left of an electrical connector and bracket, about half way up the engine block and towards the middle of the engine.

I also remember that when I opened the drain that very little coolant drained. I still plan to open this drain cock and drain the engine again the next time I change the coolant, though.

Yes, you definitely have to remove the engine undercover to find this drain cock. I remember looking up through the oil change door the last time I changed oil and I could not see the drain cock.

 

In preparation for this upcoming service (in 10K miles or so), I searched for the drain plug at my last oil change. I did not find a drain that looks like the one above (with the integral drain spout). After not finding the expected part, I researched the online parts catalogs and noticed that the part changed for cars beginning with a February 2010 build date. I think the drain plug for my 2011 (Build date 01/2011) is just a simple tapered thread drain plug (90345-52001); the older design is part number 90910-09129 that looks like the "spigot" design above.

 

As a follow-up, I also noticed from the TIS online service that the instructions changed for the 2011 models; cars built for the 2011 model year do not require opening the drain on the block any longer; only the drain cock on the radiator.

 

Thanks for this helpful information and the photo. Like Den49 I went crazy under the car trying to find the drain cock and was beginning to think I was cracking up...

Armed with this I went back out to look for the engine drain cock. It's simply not there. JDCollins5's clear description confirms. Maybe Toyota cottoned to JD's observation and saved some coin on an expensive bronze valve and tube assembly. I can see threads immediately to the side of one of the soft plugs in the engine, so I bet that's where it would have been if installed.

I used Airlift to refill, in less than 15 minutes all coolant removed was replaced with no burping or attaching to the upper drain hose nipple to watch expensive coolant flow out... See

 

The ever helpful Toyota Repair Manual shows the "Cylinder Block Drain Cock Plug", item #2.



A blow up, fwiw:



Torque for that bolt is 9 lb/ft. Seems kinda low.

I think it'd be best accessed from above, taking out the wiper motors and cowls*. I recently did that on a Civic, had to do similar. I got a real torrent of coolant when the bolt came off, maybe 50% landed in the drain pan, lol.

* Good video on how to remove that stuff:

 

Mendel,

The engine drain cock is not on top of the engine as shown in your Repair Manual attachment. Also listed in the Repair Manual the Engine Coolant Replacement steps is a Hint below:


(b) Loosen the cylinder block drain cock plug.


HINT: The plug is on the back of the generator on the exhaust manifold side.


I think the generator is a translation error and is meant to be engine or cylinder block. This hint is what led me to find it on the back side of the engine on the exhaust manifold side.

Dwight

 

I took from the diagram that it was on the rear of engine. Just good 'ol Toyota Repair Manual.

That's why I figure cowl and wiper removal would help. Nowadays you have to disassemble so much for routine maintenance.

 

You have to remove the engine under cover but you can get to it from underneath. It is about half way up the side of the engine.

You may be able to get to it after removing the wiper assembly and cowl but removing the engine under cover is much easier and quicker.

 

I'd second that, thanks for the tip. Only thing I guess, you want to get out of the way fast once you pull the plug, lol.

 

Some have claimed (in other threads) that very little coolant actually comes out that hole, if the system has otherwise been drained.

 

I've heard that too.

Recently I did a coolant change on a Civic, relatively straightforward btw. When I removed the engine block bolt (actually the block heater, in our case) a real cascade came out. The drain pan on the floor caught maybe 50%; I was mopping up for a while.

The Prius is strange: just recently I started looking for the radiator cap, lol.

 

I really did not get that much the first time I removed the cylinder drain plug. I did not bother to remove it the last time I changed engine coolant.

 

Had you first drained coolant lines to the exhaust heat recovery system as well as the radiator, or only the radiator?

 

Just the radiator.