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Where is the engine block coolant drain plug?

01-06-2005, 03:52 PM
Just changing out my antifreeze and I can't seem to find the coolant drain plug on the engine block that is shown in my manual. Anybody know where it is / how to describe where it is? Also, how important is it to use Toyota brand antifreeze?

01-06-2005, 04:37 PM
Bye-the-way, I have the 3.4L V6 engine

01-07-2005, 10:02 PM
Found it. You have to take of the skid plates and it was on the passenger side not the drivers like my manual showed. Oh well...

01-22-2005, 03:16 AM
I can't seem to locate the engine block coolant drain plug on the 3.4L V6, partly because I'm not sure what type of plug it is...any advice or direction?

01-22-2005, 08:17 AM
Also, how important is it to use Toyota brand antifreeze?

It's not. Just use any of the major brands. In fact, I see now that Prestone made it even easier for us as they now sell the antifreeze already mixed 50/50.

01-22-2005, 01:41 PM
I don't think it's as simple as switching to a major brand antifreeze. I don't know how long Toyota has used Super Long Life Coolant, but if your truck uses it mixing it with a jug of WalMart Prestone may not be a good idea. My 2004 Tacoma has the long life coolant and the first change is 100k or 120 months and every 50k or 60 months thereafter. The manual reads to use the Toyota coolant or a similar high quality ethelene glycol based non-silicate, non-amine, non-nitrate, and non-borate coolant with a long-life hybrid organic acid technology.)

The cooling protection is the same for both types but the corrosion protection may be different. Get it wrong and the coolant can eat away aluminum engine components. If you have red antifreeze it's not a good idea to replace it with the old green or yellow antifreeze. It's too difficult to get all the old coolant drained from an engine. For more information about mixing red and green antifreeze see this article that was in Car & Driver about two years ago.
Or for more information do a Google search, "mixing red and green Coolant"
Changing may not damage an engine but most professionals feel it's best to use what the manufacturer recommended. They aren't willing to gamble against the factory recommendations.


01-22-2005, 02:04 PM
Response to Timber03: If you take of the front skid plate and then look up from under the truck on the passenger side you will see a bolt / screw plug at the lowest part of the water pump assembly. Just unscrew it and out comes antifreeze. You won't be able to see it or get to it without taking off the skid plate though. Good luck.

Also, where do you find the Toyota coolant? Is there someplace that you can order it from?

01-22-2005, 04:26 PM
The Toyota owners manual reads, use Toyota coolant or one meeting their specifications. I don't know which coolants meets their specifications but look on the container for something like, (Meets requirements for Toyota's where Super Long Life Coolant is specified or similar wording). I just looked at the specifications of Havoline long life coolant and it reads very similar to the Toyota suggestions for other coolants quoted in my post above.
You may want to call a Toyota dealer and ask if Havoline long life is a suitable substitute for Toyota long life.
Here is one place you can order Toyota coolant


01-23-2005, 07:24 AM
I just read on a Prestone container the following for Corrosion Protection:

Meets or exceeds ASTM D3306 and ASTM D4985

If you really want to know if that more expensive stuff that Toyota has their label on is any better, than try and find out if their product passes any other automotive test methods that Prestone does not.

If anyone finds out let us know.

If you want to scratch your head some more, here is a ton of stuff you can read about the red/orange antifreeze vs. green antifreeze.

My Tacoma only has 60K on it. My RAV4 has 214,000 on it and I have always flushed the radiator every 2 years and never bought the Toyota antifreeze. I have never had radiator problems nor heating issues.

I didn't know the antifreeze debate is as hot a topic as oil. Very interesting.

01-23-2005, 02:45 PM
I found these descriptions of ASTM D3306 and ASTM D4885. The 3306 is telling us it's a Glycol base coolant. I believe the 4485 tells us it meets heavy duty trucks and Industrial engine requirements requiring an additive (SCA)

(ASTM D3306-03 Standard Specification for Glycol Base Engine Coolant for Automobile and Light-Duty Service)

(ASTM D4985-03 Standard Specification for Low Silicate Ethylene Glycol Base Engine Coolant for Heavy Duty Engines Requiring a Pre-Charge of Supplemental Coolant Additive (SCA) )

All vehicles I have ever owned proir to the Tacoma came with the typical geen antifreeze requiring a change every two years. Around 95-96 GM started using the extended life coolant. I noticed my 2004 Tacoma has the Super Long Life Coolant requiring the first change in 10 years or 100k miles. I did some research when I responded to this thread and learned that earlier Toyota's had a red coolant and it was a normal Glycol coolant requiring regular changes. If what I read is correct Toyota has used two different types of red coolants. I don't know how long the Super Long Life Coolant has been used and knowing that information makes a difference in what type coolant should be used. I know most antifreeze jugs will say it compatible with all types of coolant. But they usually have a disclaimer to say check your vehicle service requriements. Naturally manufacturers all say the OE stuff should be used.

I found the following information in the Texaco Extended life coolant specifications. Based on that information it is a suitable substitute for use in Japanese OEM's.
Texaco Extended Life Coolant System meets:
Phosphate free requirement of European OEMs
Silicate free requirement of Japanese OEMs
Caterpillar EC-1
Navistar B1, Type 3

It's both interesting and confusing. I liked the old
days when you bought a jug of antifreeze and you could use it knowing it wouldn't harm your engine. But we didn't have many engines with lots of aluminum content in those days. That's progress.


Brian R.
01-23-2005, 07:20 PM
Since Toyota sells so many cars, I expect that antifreeze from Prestone or Zerex will always work in my Toyota. They would be stupid to make their antifreeze so that it won't work in the most popular japanese car. If the container says: "Not for Toyota engines" or "Not for Aluminum Engines" then I will avoid it. My green Prestone that I always use doesn't have any such warning.


08-09-2005, 07:14 PM
I'm having trouble finding the engine block coolant drain plug on my '96 Tacoma 4-cyl. 4WD. Getting pretty frustrated with the stick-figure drawing in my Chilton's manual. How important is it to drain the coolant that's in the engine block? Won't it just come out when I flush the thing?

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