Having a freeze plug leak is pretty rare on cars today. That’s because there is no movement of your freeze plugs and they are a metal seal rather than a rubber gasket or o-ring. When an engine is built the freeze plugs are hammered into the plug and as they slide in the metal bends conforming to the freeze plug hole creating a really good seal. Even though they are one of the best seals on your engine, it is possible to have a freeze plug leak.
In this article, we’re going to talk through everything you ever wanted to know about freeze plugs!
How to Stop a Freeze Plug Leak?
Like any leak, you can replace it or use a stop leak. Due to the location of freeze plugs and the difficulty of installing them replacing them with a new metal freeze plug often isn’t an option. Some manufacturers make rubber expandable freeze plugs but we don’t recommend using them as they often protrude into the cooling jacket creating a hot spot and usually don’t hold up very long leaving you with a leak again. If you’re looking for a stop leak, BlueDevil Pour-N-Go Head Gasket Sealer is the right one for the job. BlueDevil Pour-N-Go head gasket sealer is a nonparticulate sealer that won’t damage or adhere to anything else in your system except the leak point. It’s permanent and guaranteed.
Why does your engine have freeze plugs?
Freeze plugs are installed to hopefully protect your engine block in case your antifreeze isn’t properly mixed. If you don’t have adequate freeze protection the freezing water in your cooling jacket can exert over 100,000 PSI on your engine block which is more than enough to crack cast iron or aluminum. A cracked block makes your engine just about useless as they are extremely difficult to repair.
Can I replace a freeze plug while my engine is in my car?
As we discussed earlier, most likely not. First of all, even a leaking freeze plug is very difficult to get out of your engine block due to the tight seal. The freeze plug will probably need to be drilled or cut out which can damage your engine block if you’re not careful. Once you get the old one out your need to pound the new one in. It takes a lot of force to press a freeze plug into a block so you need a straight shot, a big hammer, and a lot of patience. Usually, having a good enough friend that is willing to hold while you hammer is a requirement as well.
Can I drive with a bad freeze plug?
If you have no other option, you may be able to drive with a bad freeze plug. Freeze plugs rarely fall out or fail completely so they cause slow leaks. As long as you keep your engine coolant full and your engine never gets hot, you could limp your car along with a leaking freeze plug although we never recommend it. It’s messy and at any point could leak to your engine overheating.
You can pick up BlueDevil Radiator Pour-N-Go Head Gasket Sealer of your local auto parts stores like:
- AutoZone
- Advance Auto Parts
- CarQuest Auto Parts
- NAPA Auto Parts
- O’Reilly Auto Parts
- Pep Boys
- Canadian Tire
- Walmart
BlueDevil Products can be found on Amazon.com or at AutoZone, Advance Auto Parts, O’Reilly Auto Parts, NAPA, and other major auto parts retailers.
41 responses to "How to Stop a Freeze Plug Leak"
41 Comments
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Thank you I’ll try it
I will extremely use it due to more info
I see here you recommended pour and go head gasket sealer, what is the difference between that and the pour and go head gasket repair? The only sealer I could find listed 4 and 6 cylinders but I managed to get some blue devil pour and go 2x head gasket repair at my local auto parts store. Will this be suitable for an 8 cylinder truck with a leaky freeze plug?
Joshua-
The BlueDevil Head Gasket Repair is 2x the sealing power of the Pour-N-Go Head Gasket Sealer. It is double the strength and still an easy to use, do it yourself product. You would need two bottles of the BlueDevil Head Gasket Repair for your 8-Cylinder engine.
Thank you!
-BDP
Does this stuff actually work? I have a lower freeze plug leaking pretty good on my 97 chev tahoe.
Thanks!
Gina
Gina-
The product we manufacture for leaking freeze plugs is intended for seeps/light drips. As long as you are not losing water/coolant too quickly, you would be a good candidate for the product. Feel free to contact us at 888-863-0426 with any questions.
Thank you!
-BDP
I see that two bottles of head gasket repair are required for an 8 cylinder engine. How about a V10?
James-
What kind of vehicle is it? Please contact our technical support line at 888-863-0426 so that we can get a little better understanding of the vehicle and be able to make any appropriate recommendations.
Thank you!
-BDP
Will blue devil work on rubber and metal freeze plugs
Robert-
BlueDevil Head Gasket Sealer would work for metal freeze plugs, not rubber.
Thank you!
-BDP
Good afternoon, I am thinking about purchasing a 1989 Foard Coachman 450, the seller is telling me the Freeze plugs are bad and that it leaks anti-Freeze. How much BlueDevil Head Gasket Sealer would you recommend or should I simply take it to a mechanic?
James-
Yes, BlueDevil would be able to treat the leaking freeze plugs on your Ford Coachmen 450. The BlueDevil Head Gasket Sealer (32 oz. yellow label) has a cooling system capacity table on the back of the bottle, which would show you how much product to use per the system you are working with. Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
Where can I purchase blue devil sealers
Robert-
Which products were you interested in? Feel free to contact our technical support line at 888-863-0426 for direct assistance.
Thank you!
-BDP
Blud devil work on tx4 London taxi
Amjad-
Yes, the BlueDevil Head Gasket Sealer is safe and compatible to use on your TX4 London Taxi. Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
2011 Audi Q7 3.0T gas Base (premium) model, has a leaking freeze plug. What leak stop do you recommend?
Tom-
Thank you for asking about your Audi Q7. The BlueDevil Head Gasket Sealer would be the best product to use for your leaking freeze plug. As long as you are not losing water/coolant too quickly, you would be a good candidate for the product. Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
I have a 2006 Toyota Sienna and just paid $650 for a new radiator 2.5 weeks ago. Yesterday it went towards hot again…It had no water and temps tonight are said to be 26 degrees here. I went to O’Reillys and put in antifreeze. It was pouring out while I was pouring it in. Men around me were USELESS. It is NOT near the radiator
It is on the driver side and guy at the store suggested freeze plug blown out or thermostat housing shot..Can I use this product regardless to see of it will assist ??
Lynn-
Thank you for asking about your Toyota Sienna. Unfortunately, if you are losing antifreeze just as quickly as you add it, you would lose the BlueDevil just as quickly, and wouldn’t really be able to get the benefit of using it. It may be worth having the vehicle looked at by a mechanic. If it is losing antifreeze at a rapid rate, it could be a loose hose connection or the hose itself is leaking.
Thank you!
-BDP
Will blue devil fix freeze plug in a 94 jeep wrangler 2.5 it’s leaking pretty good the one n back of the motor
George-
The BlueDevil Head Gasket Sealer is intended for leaks that are seeping or lightly dripping, but would be able to seal leaking freeze plugs. Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
Ok thanks
Will blue devil fix freeze plug in a 94 jeep wrangler it. Is one of them n back of the motor it’s a 2.5 it’s leaking pretty good
George-
Yes, the BlueDevil Head Gasket Sealer would be able to treat a leaking freeze plug. As long as the leak isn’t more than seeping or lightly dripping, you would be a good candidate for the product.
Thank you!
-BDP
I have a 2011 Mitsubishi outlander weather drop real low I didn’t have antifreeze in my radiator and it froze was able to thaw it out drove it for 3 days and then it started trying to overheat would this work for me
DeLisa-
Please contact us at 888.863.0426 so that we may discuss the symptoms that you are now seeing. I am assuming that you are losing antifreeze but we want to have an idea on how quickly.
Thank you!
-BDP
I have a opel corsa lite 1.3 with a leaking welsh plug how can i stop the leak
Dixon-
The best product to use for leaking freeze plugs is the BlueDevil Head Gasket Sealer. As long as you aren’t losing coolant too quickly, you would be a good candidate for the product.
Thank you!
-BDP
I have a ram 2500 6.4L hemi. There is only the reservoir to put product in. Do I put the product in the reservoir or do I need to put in the upper radiator hose?
Brett-
If your vehicle only has a reservoir/overflow rather than a radiator cap, instead of pouring BlueDevil through the reservoir/overflow, with the car off and engine cold you should disconnect the top radiator hose and add the product there; do not pour it into the reservoir. It may be added into the hose or the opening on the radiator. Once BlueDevil has been added, reconnect the hose and start the idle from that point.
Thank you!
-BDP
I have previously used bars leak in my coolant system for a slight leak at the freeze plug. Considering that the slight leak has returned, would your product help or hurt?
John-
As long as you aren’t losing water/coolant too quickly, the BlueDevil Head Gasket Sealer would be able to treat leaking freeze plugs. We’d recommend flushing the cooling system to remove any potential contaminents/debris prior to using the BlueDevil. Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
93 Ford Ranger Tip freeze plug on back of motor has a hole. I used JB weld to try and patch but still leaks. Nowhere near as bad but still losing coolet. Will blue devil work on that?
Opy-
Thank you for asking about your Ford Ranger. The BlueDevil Head Gasket Sealer would be able to treat a leaking freeze plug, however, the JB weld could interfere. The product is attracted to a temperature differential within the system, so if the JB weld is blocking the leak point, the product may be influenced to look elsewhere for a leak. Hope this helps!
Thank you!
-BDP
On my 2012 ford fusion I have a hole in my freeze plug size of a nickel the mechanic says wat wil help?
Chris-
Thank you for asking about your Ford Fusion. The BlueDevil Head Gasket Sealer is the best product to use for a leaking freeze plug. As long as you aren’t losing coolant too quickly, you would be a good candidate for the product.
Thank you!
-BDP
Hey will it work for a brass/copper freeze plug I have put new one in but has pin hole leak I’m a little devo trying to find away to fix without doing another one and I’m in Australia do u sell the product here or do I need it shipped over…
Steven-
Yes, the BlueDevil Head Gasket Sealer would work on brass or copper. Feel free to contact our technical support line at 888-863-0426 with any other questions.
Thank you!
-BDP
Question. 98 dodge ram 1500 leaking a lot. I’m curious. What if i used jb weld on outside of the freeze plug to slow leakage completely or to a minimum leake long enough to use this product to completely stop the leakage. All sounds good in theory… what are your thoughts.
Timothy-
Thank you for asking about your Dodge Ram 1500. The BlueDevil is intended for leaks that are seeping or lightly dripping. Based on your description, it would be worth a try to slow the leakage from the outside, as to give the product a chance of working. If you are losing water/coolant too quickly, you would lose the product just as quickly. Hope this helps.
Thank you!
-BDP