Freeze Plug Block Heater Install Help

I have a '95 Chevy K1500 5.7 and am wanting to install a freeze plug block heater, but I’m having problems knocking out the existing freeze plug and would like some hints. It is located directly behind the oil filter, so I’m having problems getting enough leverage. Any ideas?

Position a punch to one side of the freeze plug and smack it with a hammer. This will cause the freeze plug to rotate in the hole in the block so it can be grabbed with a pair of pliers and pulled out.


How much force is required to smack it sideways? I can get about 2-3" of hammer swing at the most coming from the bottom up. Any ideas on another angle of approach? It looks like there’s a nice layer of grud/rusty on the rim of the freeze plug, should that be a problem?

You can simply pry the edge of the freezeplug up with a screwdriver if you get get in there enough. It’ll take some effort, but it being rusted should help. Freezeplugs a stamped metal discs, and while not soft they are bendable.

Maybe some penetrating oil will help with the rust.

Can you remove the oil filter to make more room there?

Take it back and install a tank heater…Freeze plugs are better off left alone…Especially after 16 years…

If you drill a hole in it or grind a hole in it, you can pry it out with a screwdriver or a punch. You can also push it into the hole and leave it there. Been done before.

Tom & Ray on Car Talk, June 1997 —

Ray: The freeze plug replacement heaters work pretty well, and in fact, that's what Ford gives you if you buy one from them. The heating element actually replaces a freeze plug in the engine block and heats the coolant from down there. My biggest concern about freeze plug heaters is that they can leak after installation (we've even seen a few blow out under extreme pressure). And if you don't get under the car and check it regularly, you might not know it was leaking for many moons.

Tom: So for that reason, we’re partial to coolant heaters that get installed in one of the two radiator hoses. They’re easy for your mechanic to install, the installation almost never fails, and they do a good job.

Engine Block Heaters, Tom & Ray on Car Talk, June 1997

If is a big word here. I lived in Alaska several years ago and the recommendation there was to install the type of block heater that stuck to the bottom of the oil pan. Just clean the oil pan and stick the heater on. It was simple to install and worked great even at 50 below zero. A freeze plug block heater is sometimes very difficult to install properly if the engine is in the vehicle.

When I lived in North Dakota I installed the lower radiator hose type, and it worked great. With both that and the block type the coolant will tend to circulate some via convection as the warmed coolant rises above the cooler coolant. I haven’t used the oil pan heater that Missileman alluded to, but I believe he’s a smart fella and I trust his word that it works.

Sorry for the long delay in replying. I’ve heard mixed reviews about oil pan heaters. They seem like they would work great and easy, but they only heat the oil.
I removed the oil filter to get more room to whack at it (its directly behind the filter) but I will have to try again now that I’ve got a punch (I was trying a old screwdriver before).
What’s a tank heater? I’m assuming it is placed directly into the anti freeze overflow tank? Sounds easy, but it seems it would be heating the tank more then the block
The same thought of mine goes with the lower radiator hose style, as it seems less effective?


Nothing placed in the anti freeze reservoir will help. I’m unfamiliar with tank heaters. I tried looking them up and they appear to be a heating element and small pump in a seperate tank that circulates the coolant.

I can testify from personal experience that the lower hose heater does work well. Block heaters also work well. There used to be heaters on the market that replaced the oil dipstick, and those are of limited value.

I had a factory block heater go bad and it cost me $35 to have the whole thing replaced. Just a thought rather than struggling with it for days maybe laying under the truck.

While the heaters in the hose work fine, I never liked them because of having to cut either the radiator hose or the heater hose to fit them in. Today though, you really don’t need them to start cars in the winter unless you live in Canada or Alaska.

I’m new to Southern Montana, and it’s been recommended by the locals to install a block heater for the extra cold days (-20), so it might not be needed, but its been recommended.

I have had block heaters since 89 when I moved to North Dakota. I had one installed in each of my vehicles when I moved there. The last 3 cars bought in WI have had a factory installed Block Heater. In ND most places have outlets to plug your car into. In WI 15 degrees and below I plug our cars in. The basic philosophy I have heard is most engine wear occurs 30 seconds after you start the car. It keeps your engine block at 35 deg or so, the oil is less like molasses and the starting is better. 20 below, you may not start without one. Failure for any reason of block heater non existent in my experience. The problem with the inline hose heater is they are typically 400 watt min, vs 100 watt for a block heater. In the case of my trailblazer the lower hose goes to the thermostat, so you will spend 400 watts per hour to heat up the radiator. The block heater is the most cost effective efficient thing out there. Do not fall for the magnet mount oil pan heater, or the dipstick heater because IMHO they are a waste of money and the dipstick heater can fry your oil. I know in ND it was block heater.period end

I say that you fill your block with straight water and wait for the freeze plug to pop out in the mid of winter… NO NO NO… JUST KIDDING…thats silly. SORRY…could’nt help myself lol

Hmmm lets see I can understand your frustration with this one. If you dont have adequate room to use the punch and hammer method… I have to ask…DO YOU HAVE A WELDER? You could weld yourself up a “pull” for the lug…OR…Have you ever seen the “Weld a Pin” device?..sort of looks like a glue gun…but it is actually a type of spot welder… It welds little “pins” to mild steel so that they can be pulled on …usually to remove a stubborn dent in sheetmetal. You may be able to go to a body shop and have a guy just Zap on a Pin for you…then you just pull on the pin and out she pops… It would be best to weld the pin on the plug lopsided…to encourage the plug to rotate.

Other than this method… I would try to drill a hole in the plug and then use a thick sheet metal screw…as your “pin” and try the same thing maybe?

Interesting problem. You could always pull BOTH of your Motor mount bolts and raise the engine up out of the way… I believe that there is a Freeze plug hiding behind a motor mount on the 5.7L… No? But anyway…removing the motor mount bolts will buy you quite a bit of new found room to play

ALSO…What if you simply Knock the plug INTO the block? … You could then deform it while its in the block and pull it back thru the hole… Hell I dont think it would go anywhere or do any harm if you simply knocked it in and even left it there to be honest

No I don’t have access to a welder! I think I may be able to knock it out with just a hammer and punch. I just have to get the right angle of attack.

I say you smack that thing INTO the block…HIGHLY doubt it will cause any issues even if you didnt get it out of the block actually. But my theory is to knock it in…then deform it and pull out the hole? Maybe I’m nutz but I do things like this from time to time. Hard to say what I’d do without being there to see it.

The problem I had before was that I couldn’t get enough swing on the hammer to actually whack the heck out of the thing (maybe 2-4" of swing total?). I’m going to try tomorrow again, and see if I can find a different angle. I may end up jacking the front of the truck up to see if that helps get more clearance…