THE Definitive Block Heater Coolant Plug Removal Thread

[1960mog]

Hit the plug with a hammer before removal.
The idea is to compress the aluminum seal ring and break loose the threads.
After the hammer treatment i use a 30" long 1/2" breaker bar and a Hazet 19mm Allen socket.
Works every time.

[TomAllen]

I've succeeded at this once in two tries. Same method each time on 2 617 turbos in the car a 300SD. Tools are a 3/4-drive 19mm hex bit, a 3/4-drive breaker bar and the 4' handle of my floor jack. Oh, and a 6" 3/4-drive extension.

Took the air cleaner off. Then from above inserted the hex bit, breaker bar, extension and jack handle. Positioned the now 6' bar at just below shoulder height, squatted down, put my shoulder to it and heaved with my legs. Came loose in one try with considerable flexing in the bar.

The next attempt was just a year after I broke my hip in a bike wreck and I was afraid to put so much force into it for obvious reasons. I failed and decided to wait a year. So that is now. Maybe I'll get my 6'7" neighbor to provide the oomph.

[disqo]

Well it only took like a month and two broken 1/2" drive breaker bars, but I finally succeeded in removing the block heater plug from my project car. I ended up getting it by removing the intake, exhaust and turbo (which I was planning to do anyway), liberally applying kroil for like the last month, heating the plug for about 20 minutes, and using a four foot cheater pipe on a 3/4" drive breaker bar with a 19mm hex drive bit. The drive on the breaker bar was starting to twist and I was afraid it was going to break too before the plug finally broke loose. Even when it did break loose it only turned like an 8th of an inch at a time with all of my force behind it. I am glad it finally worked and I hope I never have to do it again!

[vstech]

Hmmm

I've got 3 617's on the floor of my shop... and a 19mm allen wrench, and some pipe... I'm gonna try it with NO HEAT!!!

I may even video the attempt.

[whunter]

Originally Posted by vstech

Hmmm

I've got 3 617's on the floor of my shop... and a 19mm allen wrench, and some pipe... I'm gonna try it with NO HEAT!!!

I may even video the attempt.

Please don't break any bones.

A couple months ago, I tried exactly what you plan: the engine/trans assembly flipped.

Chain the engine to your big truck, or you might be wearing the cheater pipe.

.

[vstech]

I will chain the motor down. thanks for the tip!

[macdoe]

That block heater is pretty close to the cyl. head....I wonder if that much (30 min) localized heat from a propane torch after the coolant has been drained out would do something bad to the headgasket or the head itself? Maybe leaving the coolant in would help carry away the "too much heat" or absorb it, to avoid damage to the head/headgasket? Great job too on write up, except that part. That part I would not do to my engine. our site probably should'nt condone it either...What do the experts in the mechanics field say?

[macdoe]

That block heater is pretty close to the cyl. head....I wonder if that much (30 min) localized heat from a propane torch after the coolant has been drained out would do something bad to the headgasket or the head itself? Maybe leaving the coolant in would help carry away the "too much heat" or absorb it, to avoid damage to the head/headgasket? Great job too on write up, except that part. That part I would not do to my engine. our site probably should'nt condone it either...What do the experts in the mechanics field say?

[whunter]

Recycled
for new members

[vstech]

all my blocks have the heater in them already... so, I'll not be playing the plug pull game... dang.

[Simpler=Better]

I can't ever pass up an opportunity to show off:




I used a 3/4" giant allen wrench, and 5ft cheater bar. Thought the block was going to crack.

[BillGrissom]

I tried removing the plug on a used engine, but gave up. My orginal engine had a block heater, so wanted to swap. I bought a giant hex wrench at Ace (19 mm, ~$17, recall) and used a cheater pipe. I recall trying a propane torch too. Decided to wait until a day when I had the manifolds off and engine installed.

[vstech]

I think my idea on plug removal with no heat will work.

First, tap on the plug with a ball peen hammer. Don't go crazy, just tap on it for a few minutes. Next soak it in PB blaster or aerokroil if you have it, for a day. Next, beake spray the nut clean and let it dry. Next, with at least a 3/4"breaker bar and socket tightly fit in, TIGHTEN THE NUT INTO THE BLOCK FIRST. Just bang tighten it a few times. Then, spray more penetrant... Let it soak, and then apply loosening force solidly to the bar... While solid force is applied... Smack the socket with the ball peen hammer.
Let me know if it works.

[Squiggle Dog]

I just installed a block heater in my 1980 W116 300SD. I already had the manifolds off for non-EGR swap (my car is a California emissions model) and turbo rebuild. I had been wanting to install one in case I visit a cold climate and thought it was "now or never".

I almost didn't do it, though, because I don't really have the money and figured it would take about a week before one would arrive. EBay had some good deals, as did some online parts stores. It seemed I had two choices: genuine Mercedes-Benz which was about $200 (and was made in Canada) or a Zerostart (love the name), which was a lot cheaper and also made in Canada (maybe they make the genuine Mercedes ones?).

The Zerostart appeared to be very high quality and I chose it over genuine Mercedes-Benz, not just for the price, but because it was only a one-piece unit and had a nicer power cord arrangement with a cap to cover the prongs.

I looked up block heaters on O'Reilly Auto Parts' website just for fun and they had one of the Zerostart block heaters at their warehouse for only $60. So I had them order one in and had it the next day. The part number is 310-0105 or Q6200009 and fits 38mm plug threads. It looks like Pelican Parts has genuine Mercedes-Benz ones for only $39! Mercedes-Benz Block Heatr Kit Q6200009 - Pelican Parts They also have the Zerostart heater: Engine Heater 9002034895 - Zerostart - 900-203-48-95 | Pelican Parts .

To remove the plug, I bought a Husky hex key socket set from The Home Depot for $25. It came with the proper 19mm hex key and also had a 3/4" key which is the same size if the first were to break. O'Reilly Auto Parts had a smaller set for $20 with only the 19mm key, so that was an option.

I tapped on the plug (not the block) with a sledge hammer and then I put the 19mm hex key socket on a 36" breaker bar with a 24" pipe slid over the end, gave it some force, then pulled it back toward me, and then back the other way. It didn't budge.

So, then I tapped the plug with a hammer again, then put a MAPP gas torch on the plug for about 10 seconds. I put the socket back in the plug, pulled the breaker bar toward me, and then pushed it away and jarred against the bar a few times (which was bowing quite a bit). I finally heard a SNAP! and then I was able to turn the plug a bit. So, I drained the coolant from the block, then loosened the plug while rocking it back and forth a bit to clear up the threads.

The new block heater came with an aluminum crush washer. The plug that came out of the block had no apparent sealing ring. I installed the block heater with the aluminum crush washer and a little bit of anti seize compound on the threads.

The block heater takes a 46mm socket to install. They can be ordered in at auto parts stores but are usually at least $30 each. I was at Harbor Freight with my roommate and they had a 20 piece jumbo SAE socket set (of the highest quality ) for $130 on sale for $60. He had a coupon and ended up getting it for $47, so he let me use the 1 13/16 socket which fit perfectly. There were no torque specs, so I tightened it using the breaker bar and my judgment.

The power cord can attach 180 degrees in either direction. I ultimately had the cord point toward the firewall and routed it with the battery cables under the heat shield toward the front of the car, coiled up the excess length and tied it with a strap, then routed it out under the right headlight and behind the bumper so it can be plugged in without opening the hood (which let's assume would be frozen shut and covered in a foot of snow if I ever get to use it).

[kuene]

wow that is a beautifully clean engine!