How to install Freeze Plugs
04-20-06, 02:30 PM
#1
How to install Freeze Plugs
Hey Everybody,
Well I've got my engine bay half torn apart for the ultimate spring cleaning, and I decided I was going to install some freeze plugs so that I could swap intake manifolds easier.
So for those un-initiated among us, here are a few Q&A so you know what I'm talking about
Okay, what are "freeze plugs"?
- Freeze plugs (also known as frost plugs, or expansion plugs) are small metal caps which are hammered into coolant holes in the engine blocks of cars. Pretty much every block has some of these, and they generally serve two purposes. To block the hole (and stop coolant from escaping), and to allow expansion of the coolant if it freezes. If your coolant isn't mixed well and it freezes, the plugs will often pop out, giving way for the expanding coolant, often times saving your engine. They're usually installed during the manufacturing process.
... and why would I need some of these, after my engine has already been built?
- There are two coolant holes which allow coolant to flow into your intake manifold. Any time you remove the intake manifold, you also drain out all the coolant in the system that sits at or above the level of those holes. This can be annoying if you want to change intakes, but don't want to drain your coolant to do it.
- Also, there are some people who say that having hot coolant coursing through your intake manifold warms up the intake charge making it less dense, yadda yadda.... Basically the same school of thought as the "Cold Air Intake" crowd. So blocking off these holes may contribute to the efficiency of your intake by keeping the intake "cool" instead of warming it up.
In my case, I already had my engine bay apart and my radiator out being rebuild (so all fluid drained), but my new intake manifold had not arrived yet. So I figured I'd take the time to install the freeze plugs so that swapping on the new intake later would be as easy as a couple of bolts and nuts.
So here's the simple instructions on how to install your freeze plugs.
Required Materials
12mm Socket
Wratchet and Long (10in) Extender
New Intake Manifold Gasket
2x 20mm Freeze Plugs
Either a 14mm Socket or an 8mm Hex (allen-key style) tool/socket
2.5lb "club" hammer (or any suitably heavy hammering device that can be held in one hand and isn't too big)
Optional Materials
Brass Wirebrush (or a few)
Putty Knife (to scrape off gasket material, a flat screwdriver will do in a pinch)
White Silicone
1. Remove the Carb
- This would be an entire write-up in itself (and might end up being at some point) so I'll not cover all the details here. This write up will assume you already know how to do this, or can figure it out pretty easily. If you need help, search first, then PM me when/if you don't find anything.
2. Drain the Coolant
- For this writeup, we don't need to drain all the coolant, just everything higher than the intake holes. There are two ways to do this. Either you can drain all the coolant from the engine and above through the coolant drain nut on the driver's side of the engine, OR you can remove the two coolant plugs on the intake manifold itself. (labeled "Not These" in the pic, you normally wouldn't remove these because you'd have to reinstall them with damn good threadlock to prevent leaks)
The first of these methods drains more coolant, but is slightly easier since it can be done with a simple 14mm socket and placing the pan on the ground. The second method drains less coolant, but needs an 8mm hex-key socket and you have to hold the pan near the intake, which is a feat of balancing all it's own.
- If you're going to do any other coolant-related work, you'll need to drain all of the coolant. You have to drain from *two* points to do this. Use the 14mm drain plug that we already mentioned on the driver's side of the engine, but then you also have to remove the lower radiator hose. The reason for this is the position of the water pump. All of the coolant in the rad below the water pump doesn't have a way to get into the engine and drain through the drain plug, so you have to take off the lower rad hose to get it out
3. Remove the Intake
- Remove any hoses that might be holding the manifold back (in my case, the brake booster hose, and the hose I used for my PCV valve)
- There are four bolts and two nuts holding the intake on. The nuts are elusive, hard to spot little buggers. I've included a pic of the removed manifold to help folks out. The 4 bolts are in yellow, the nuts are in green and labeled "Remove These". Once the bolts and nuts are off, the manifold should just fall right off.
4. Clean the GUNK
- If your manifold is like mine (never been removed in 20yrs) you'll find that the gasket is decimated, the rubber washers around the coolant holes are broken and stuck, and there's gunk everywhere. Use a putty knife or flat screwdriver to remove the old gasket material and clean the area as best you can. Brass bristle wirebrushes are good to use here. They don't mess up your aluminum (unless youre really rough with them) but they clean things up quite well. You'll also want to clean out the outer inch or so of the coolant holes, so that we have a nice clean surface to install the freeze plugs into. Don't forget to spend some time cleaning the manifold side as well.
5. Install Freeze Plugs
- Smear a thin coat of clear silicon on the inside of the coolant hole and a bit on the freeze plug as well. Use the wratchet end of the 10mm extention on the inside of the "cup" of the freeze plug. Place the freeze plug over the hole and carefully hammer it into place. You want to make sure that it goes in as evenly as possible. I was lucky enough to have a spare engine lying around that I could try on first, but it wasn't that difficult. The only thing I noticed is that light rubber mallets are nowhere near enough to drive that thing in. So I bought a 2.5lb mini-sledge. Carefully drive the plug in until it's about 1mm (1/4"?) below the surface.
The plug will shrink to fit the hole, so it will clamp slightly around your extender, don't worry about it too much, it will come out. When I did my test engine I used a 12mm socket because it fit snugly in the freeze plug, but it got stuck when the plug started to crimp inwards.
6. Install new gasket and intake
Now that you've hammered both your freeze plugs in place, all that's left to do is reinstall your intake with a new gasket, reinstall your carb, fill it with antifreeze and take it for a ride. Before you go out riding, you want to let the car idle and top up the antifreeze, trying to get any air pockets out.
Jon
Well I've got my engine bay half torn apart for the ultimate spring cleaning, and I decided I was going to install some freeze plugs so that I could swap intake manifolds easier.
So for those un-initiated among us, here are a few Q&A so you know what I'm talking about
Okay, what are "freeze plugs"?
- Freeze plugs (also known as frost plugs, or expansion plugs) are small metal caps which are hammered into coolant holes in the engine blocks of cars. Pretty much every block has some of these, and they generally serve two purposes. To block the hole (and stop coolant from escaping), and to allow expansion of the coolant if it freezes. If your coolant isn't mixed well and it freezes, the plugs will often pop out, giving way for the expanding coolant, often times saving your engine. They're usually installed during the manufacturing process.
... and why would I need some of these, after my engine has already been built?
- There are two coolant holes which allow coolant to flow into your intake manifold. Any time you remove the intake manifold, you also drain out all the coolant in the system that sits at or above the level of those holes. This can be annoying if you want to change intakes, but don't want to drain your coolant to do it.
- Also, there are some people who say that having hot coolant coursing through your intake manifold warms up the intake charge making it less dense, yadda yadda.... Basically the same school of thought as the "Cold Air Intake" crowd. So blocking off these holes may contribute to the efficiency of your intake by keeping the intake "cool" instead of warming it up.
In my case, I already had my engine bay apart and my radiator out being rebuild (so all fluid drained), but my new intake manifold had not arrived yet. So I figured I'd take the time to install the freeze plugs so that swapping on the new intake later would be as easy as a couple of bolts and nuts.
So here's the simple instructions on how to install your freeze plugs.
Required Materials
12mm Socket
Wratchet and Long (10in) Extender
New Intake Manifold Gasket
2x 20mm Freeze Plugs
Either a 14mm Socket or an 8mm Hex (allen-key style) tool/socket
2.5lb "club" hammer (or any suitably heavy hammering device that can be held in one hand and isn't too big)
Optional Materials
Brass Wirebrush (or a few)
Putty Knife (to scrape off gasket material, a flat screwdriver will do in a pinch)
White Silicone
1. Remove the Carb
- This would be an entire write-up in itself (and might end up being at some point) so I'll not cover all the details here. This write up will assume you already know how to do this, or can figure it out pretty easily. If you need help, search first, then PM me when/if you don't find anything.
2. Drain the Coolant
- For this writeup, we don't need to drain all the coolant, just everything higher than the intake holes. There are two ways to do this. Either you can drain all the coolant from the engine and above through the coolant drain nut on the driver's side of the engine, OR you can remove the two coolant plugs on the intake manifold itself. (labeled "Not These" in the pic, you normally wouldn't remove these because you'd have to reinstall them with damn good threadlock to prevent leaks)
The first of these methods drains more coolant, but is slightly easier since it can be done with a simple 14mm socket and placing the pan on the ground. The second method drains less coolant, but needs an 8mm hex-key socket and you have to hold the pan near the intake, which is a feat of balancing all it's own.
- If you're going to do any other coolant-related work, you'll need to drain all of the coolant. You have to drain from *two* points to do this. Use the 14mm drain plug that we already mentioned on the driver's side of the engine, but then you also have to remove the lower radiator hose. The reason for this is the position of the water pump. All of the coolant in the rad below the water pump doesn't have a way to get into the engine and drain through the drain plug, so you have to take off the lower rad hose to get it out
3. Remove the Intake
- Remove any hoses that might be holding the manifold back (in my case, the brake booster hose, and the hose I used for my PCV valve)
- There are four bolts and two nuts holding the intake on. The nuts are elusive, hard to spot little buggers. I've included a pic of the removed manifold to help folks out. The 4 bolts are in yellow, the nuts are in green and labeled "Remove These". Once the bolts and nuts are off, the manifold should just fall right off.
4. Clean the GUNK
- If your manifold is like mine (never been removed in 20yrs) you'll find that the gasket is decimated, the rubber washers around the coolant holes are broken and stuck, and there's gunk everywhere. Use a putty knife or flat screwdriver to remove the old gasket material and clean the area as best you can. Brass bristle wirebrushes are good to use here. They don't mess up your aluminum (unless youre really rough with them) but they clean things up quite well. You'll also want to clean out the outer inch or so of the coolant holes, so that we have a nice clean surface to install the freeze plugs into. Don't forget to spend some time cleaning the manifold side as well.
5. Install Freeze Plugs
- Smear a thin coat of clear silicon on the inside of the coolant hole and a bit on the freeze plug as well. Use the wratchet end of the 10mm extention on the inside of the "cup" of the freeze plug. Place the freeze plug over the hole and carefully hammer it into place. You want to make sure that it goes in as evenly as possible. I was lucky enough to have a spare engine lying around that I could try on first, but it wasn't that difficult. The only thing I noticed is that light rubber mallets are nowhere near enough to drive that thing in. So I bought a 2.5lb mini-sledge. Carefully drive the plug in until it's about 1mm (1/4"?) below the surface.
The plug will shrink to fit the hole, so it will clamp slightly around your extender, don't worry about it too much, it will come out. When I did my test engine I used a 12mm socket because it fit snugly in the freeze plug, but it got stuck when the plug started to crimp inwards.
6. Install new gasket and intake
Now that you've hammered both your freeze plugs in place, all that's left to do is reinstall your intake with a new gasket, reinstall your carb, fill it with antifreeze and take it for a ride. Before you go out riding, you want to let the car idle and top up the antifreeze, trying to get any air pockets out.
Jon
Last edited by vipernicus42; 04-20-06 at 02:38 PM.
04-20-06, 03:52 PM
#2
Nice write up Jon. I have one suggestion. I find J-B Weld works better than the silicone. It sets faster, (don't need to wait 24 hours before coolant fill), and it's stronger. Which ever is used the surface needs to be thoroughly cleaned for good bonding and seal.
04-21-06, 07:44 AM
#5
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Nice writeup. And thanks for reminding folks to burp the air out of the coolant system after they refill.
I've installed a plastic Prestone 5/8" tee in that lower heater hose on the passenger side on each of my cars. It only costs $6 at any autostore, comes with a screwon cap and attachment for a garden hose, and really simplifies draining coolant or flushing the engine.
Is there any reason to NOT install freeze plugs? Is the warm coolant required to meet smog requirements?
I've installed a plastic Prestone 5/8" tee in that lower heater hose on the passenger side on each of my cars. It only costs $6 at any autostore, comes with a screwon cap and attachment for a garden hose, and really simplifies draining coolant or flushing the engine.
Is there any reason to NOT install freeze plugs? Is the warm coolant required to meet smog requirements?
04-21-06, 03:26 PM
#6
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I don't know about emmissions, but I think the main reason for the coolant going thru the intake, is to prevent carb icing during cold weather. No problem, just don't drive it when it's that cold...........
04-22-06, 09:28 AM
#7
Coolant through the intake makes the carb warm up faster. Just like the air hose that our cars have connecting the heat shield around the exhaust manifold to the intake snorkel. It's all an elaborate system to make the car warm up as fast as possible. Why? Because a warmed-up car produces less emissions than a cold one. The warm-up sequence is always being tweaked by the manufacturers to get it as short as possible. The thermostat is another one of those things. It keeps coolant IN the block until the block is warm enough, then opens to let the cooler coolant from the rad to circulate through.
The idea is to reach operating temp as fast as possible, but still be able to prevent the car from overheating.
In my case, the incredibly small benefit to warm up time caused by the coolant in the intake manifold and the stock airbox/tube from heat sheild system is negligable. I can do without it.
So I install freeze plugs, remove the heat shield and hose from the exhaust manifold, and replace the airbox. Sure my car takes another thirty seconds to reach operating temp, but I'm not THAT impatient
Jon
The idea is to reach operating temp as fast as possible, but still be able to prevent the car from overheating.
In my case, the incredibly small benefit to warm up time caused by the coolant in the intake manifold and the stock airbox/tube from heat sheild system is negligable. I can do without it.
So I install freeze plugs, remove the heat shield and hose from the exhaust manifold, and replace the airbox. Sure my car takes another thirty seconds to reach operating temp, but I'm not THAT impatient
Jon
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04-28-06, 07:04 PM
#8
i went to go buy the plugs so i could do this along with my list of other thinsg i need to do over the weekend, and i cant find a single place that sales 20mm freeze plugs. does it have to be exactly 20mm or will another size work? the closests ive found in metric is 18mm and 21mm. i need to know ASAP. thanks
04-28-06, 08:38 PM
#11
For me I got them at a local place that rebuilds engines called "Engines Extra"
The guy literally went into the garage where they do the rebuilding, got some from their own stash of freeze plugs, and came back out again.
Napa etc... won't have 'em. Check around for local engine rebuilding places. Even piston engine rebuilding places will have 'em because japanese engines of almost any type will use them.
I just opened up the yellow pages, looked under "engines" and called places until I found a place that had them.
There are "small" or "shallow" ones and there are bigger ones. I used the shallow ones because that's all they had left, and they worked just fine.
Jon
The guy literally went into the garage where they do the rebuilding, got some from their own stash of freeze plugs, and came back out again.
Napa etc... won't have 'em. Check around for local engine rebuilding places. Even piston engine rebuilding places will have 'em because japanese engines of almost any type will use them.
I just opened up the yellow pages, looked under "engines" and called places until I found a place that had them.
There are "small" or "shallow" ones and there are bigger ones. I used the shallow ones because that's all they had left, and they worked just fine.
Jon
04-28-06, 08:56 PM
#14
I have boxes of zinc metric expansion plugs here at the shop, but I don't know how much we paid. If I remember to ask Rob tomorrow, I can throw some up on the web site online store and you can place an order.
04-29-06, 01:20 AM
#15
this came just in the nick of time. i was out in the garage doing some porting tonight and i was looking at the rotor housings and wondering what would be the cleanest way block those passages. i'll try to get some before i put it back together. thanks, Jon.
04-29-06, 07:37 PM
#21
i just thought of something, what about screw in plugs??
if anyones knows the dimensions of the holes i think id rather go with the plugs. also, are all the wholes on all housings the same? if so, i have a spare 2nd gen housing i could take with me to test fit plugs to.
if anyones knows the dimensions of the holes i think id rather go with the plugs. also, are all the wholes on all housings the same? if so, i have a spare 2nd gen housing i could take with me to test fit plugs to.
05-02-06, 07:22 AM
#22
Attack Gas Station!!!!
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Originally Posted by aws140
i just thought of something, what about screw in plugs??
something like the following made by moroso:
05-02-06, 08:27 AM
#23
Tapping things makes metal shavings, which I wouldn't want in my coolant passageways...
As I said, call local engine rebuilders. Anyone who rebuilds engines for imports will have them in stock, whether they usually retail them or not, they'll give 'em to ya for a few bucks.
If I was going to tap them, I'd do it when the engine was dissasembled for rebuild.
Jon
As I said, call local engine rebuilders. Anyone who rebuilds engines for imports will have them in stock, whether they usually retail them or not, they'll give 'em to ya for a few bucks.
If I was going to tap them, I'd do it when the engine was dissasembled for rebuild.
Jon
05-02-06, 08:46 AM
#24
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Originally Posted by vipernicus42
Tapping things makes metal shavings, which I wouldn't want in my coolant passageways... If I was going to tap them, I'd do it when the engine was dissasembled for rebuild.