Freeze Plugs - Dumped coolant - Maintenance item?
 

I had a very bad coolant leak over the weekend. I was lucky to have it happen on a 10 minute trip from my house where I pulled up, got out of the truck, and immediately saw coolant dumping out. I had it towed to a mechanic who found a popped freeze plug.

Some possibly relevant background: I recently (2 weeks ago) noticed that my top hose was sucked in after the engine cooled, figured bad radiator cap, and replaced the cap. The purpose of pointing this out is that in the recent past, my cooling system may have been underpressurized and is now seeing the correct amount of pressure. I do not believe that, at any point, this truck had overheated. I am pretty diligent about checking things out and the gauge never creeped or ran low on coolant

I'm a decent garage mechanic/hobbyist and this is the first time I've heard of a freeze plug. My truck is well maintained otherwise and received timing belt, water pump, rust remediation, new suspension, etc. in the last year and I'm committed to it at this point. Are freeze plugs a maintenance item that should be considered with an aging 5VZ-FE or is it just a factor of luck + age? Should I consider having more of them replaced than just the one that popped out? Are others noticing freeze plugs popping out as these things age?

Never read of another on here, of course I can't read Everything but looking thru the list of How To videos (132), none on that topic.

Looking thru Buyer's Guide, never mentioned.

Just doesn't look like a common problem, could be wrong but does not appear to be common.

Gotta wonder Why it got pushed out. Let's see what others say....

Are there any corrosion?
You said the freeze plug is pulled into the inside of the engine?

I believe the freeze plug pushed out, not in. Corrosion, I do not believe so but have not seen it for myself.

I have never heard of a freeze plug pop out on its own unless your coolant actually did freeze. Do you have too much water in your coolant, causing it to lose its antifreeze properties?

Coolant was very red when it leaked. I didn't mix it myself, a shop replaced my water pump in January of last year and filled it. I trust the shop and it didn't have an issue through last winter. In MD, we've barely flirted with freezing temps this fall/winter season.

I cannot guarantee it had enough anti-freeze but I do trust my mechanic and it was Toyota-red. The likelihood that it didn't freeze last february, causing issues then, and issues arose just now I think is enough to write that off.

If this is just an unlucky issue, so be it. I'll be glad for that to be the case but it will always be on my mind now when taking long road trips, lol. I did find a few instances on tacoma forums but nothing really seemed concise in terms of when, why, or which plugs. Seems kinda luck of the draw unless corrosion is present. Even at that though, corrosion usually seems to freeze things in place so I'm surprised that would contribute to them popping.

First case I've heard on this engine, but this could also happen to any engine. I think you just got unlucky.

Rebuilt engine?
I've never heard of this issue in stock 4Runners or other Toyota trucks either.

I havent heard of it nor seen any Toyota engine do that in 30 years I been working on them. Mostly truck and Camry engines I dealt with.

Only issue that was persistent all these years was getting the engine too hot are warping the aluminum heads causing head gaskets leaks. Interesting one indeed. Thanks for sharing and keep us posted. :)

Sent from my SM-J337V using Tapatalk

Well that makes me feel a bit better but still bummed it happened. This was a one owner car before me that did tell me that in the first year of its life, someone forgot to fill it with oil during a change. Toyota replaced the engine at that time but I believe it was a new Toyota engine.

Haven't gotten it back yet. Mechanic is going to try to press in the new freeze plug in place as opposed to removing the engine. I needed some re-assurance that another one isn't going to blow out on me, lol.

Interesting, I've only read of someone having a leak between the tranny and motor frost plug(Florida truck may not have had coolant in it) and a popped block heater. He should be able to hammer a new one in with a punch, or if it's in a spot that will accept a block heater and you live in a cold climate that might be a solution.

Ok. So engine replacement and someone somewhere made a mistake. Hard to say what the dealership done. As it most likely be on their dime. Maybe they put a jasper engine in.

In any case, I would just occasionally check your soft plus for seepage for a while and if one seeps replace it immediately. What else can you do at this point. Major bummer but at least you know to inspect them from time to time.

Sent from my SM-J337V using Tapatalk

Meh, engine replacement was done in 2000 or 2001. I'll keep an eye on them but I don't think 19-20 years later, I'm seeing an impact from a replaced engine.

Yup. That you are and most likely a 3rd party remfg engine. With cheaper plugs in it. Oh well actually minor could be alot worse then this. I just extremely rare. You must be special...;)

Sent from my SM-J337V using Tapatalk

Once it went under the knife, mechanic realized it was a block heater and not a freeze plug. My truck was originally sold in Michigan and came with a block heater apparently. It's now been replaced with a freeze plug. Luckily it was accessible enough for them not to pull too much off or need to pull the engine.

PSA to all - May be worth checking your block heater's seal at this age. I didn't really get a warning to my seal failing and was very lucky to have mine break when it did.