# Coolant plugs on engine?? 1.8, 8V, MKII



## Warp (Feb 17, 2007)

Hi all!!
I had a coolant leak from the manifolds side of the engine. Coolant spilled over the hydraulic steering and part of the passenger side front suspension arm.
I see no hoses there and I couldn't track exactly where the leak is coming from. However, I know there are no hoses or flanges on that side so my gut feeling is a blown head gasket.
Oddly, I have no traces of coolant in the oil and car continued running fine for the 5min (give or take a couple) it was running with no coolant.
I've been told by some wrench that it could be some "plugs" that are in that area.
Is that true?
Are there any plugs for coolant on that side of the engine?
I can't find any reference to them so I'm thinking I'm more likely to replace the head gasket.
Thanks for any pointers.
Warp
Car is a VW Golf GL 1987 (Mexican Spec for Mexican Market) Auto Tranny.
Engine is a 1.8, 8V, Code NX0, Pierburg 2E Carb.


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## Cyrus #1 (Sep 29, 2005)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Warp)*

The plugs they are speaking of are called "frost plugs." They are for us suckers in the great white north!







Basically they are there in case the coolant has too much water in it and freezes. The idea is that the plugs will push out from the expanding water and prevent the block from cracking.
If you can devise some kind of way to feed low pressure compressed air into the cooling system, it should help you pinpoint the leak. I've never personally seen a leaking frost plug but I suppose it's not impossible. You could also try topping up the cooling system and running the car for a short period of time to locate the leak. http://****************.com/smile/emthup.gif


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## Warp (Feb 17, 2007)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Cyrus #1)*

Thanks!!
Anyone has a pic of where are they located?? I've made a search since you pointed me to "frost plugs" but files are lost.
I think the dang starter it's on the way... This auto tranny car has a really fed up starter design.


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## Fat Rabbit (Nov 18, 2001)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Warp)*

The plugs are located on the back side of the engine -- just under the exhaust manifold. I have seen them rust through before and weep coolant. The plugs are inexpensive but can be tough to replace without removing at least the downpipe. They come out OK but it's tough to put the new ones in because of limited access


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## Warp (Feb 17, 2007)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Fat Rabbit)*

Thanks for the input, F-Rabbit!!
I'll get hands on.
Please cross fingers so it would be just a frost plug and not the head gasket.


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## ABA Scirocco (May 30, 2001)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Cyrus #1)*


_Quote, originally posted by *Cyrus #1* »_The plugs they are speaking of are called "frost plugs." They are for us suckers in the great white north!







Basically they are there in case the coolant has too much water in it and freezes. The idea is that the plugs will push out from the expanding water and prevent the block from cracking.


That an old wives tale, that's not why they're there, if they were, they would pop out much more easily the sad truth is if your block freezes hard enough to pop the plugs, it's probably already cracked. 
The "frost" plug hole are in fact just left over from the sandcasting process used to manufacture the block, the holes were there to support the sand cores and to provide somewhere for the sand to come out after the block's been cast.
Anyways, regardless of why they're there, that does seem to be the OP's problem. You can see them in this picture, they're the 3 circular indentations a few inches below the deck.


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## Warp (Feb 17, 2007)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (ABA Scirocco)*

That makes it much more easier!!
Thanks Cyrus!
I have already located where the "1.8" mark on my engine. I'll look around.
But I think the heat shield gets in the way.
The heat shield protects the starter on automatic geared cars and it sits below the exhaust manifold.
Now I know where to look for. I'll refill with water to find out the leak and purge the water out before refilling with coolant.
Thanks everyone!


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## ABA Scirocco (May 30, 2001)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Warp)*

BTW, there's one more "frost" plug not shown in that picture, hopefully, that's not the one causing you problems becasue it's a HUGE pain, it would require removal of the tranny to replace.


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## Cyrus #1 (Sep 29, 2005)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_The "frost" plug hole are in fact just left over from the sandcasting process used to manufacture the block, the holes were there to support the sand cores and to provide somewhere for the sand to come out after the block's been cast.

That makes sense now that you mention it. It sounds like a bit of slick marketing to me. Just like the cars that have "child proof" rear windows that only roll down part way. But you look closer and the door line clearly won't allow the glass to go down the whole way.


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## chickenfriend (Jan 31, 2005)

*Re: Coolant plugs on engine?? 1.8, 8V, MKII (Cyrus #1)*

It is going to be very difficult to deal with rusted up coolant plugs on the backside of the engine. I would suggest you consider removing the engine and replacing all (4?).
Try hitting them at the edges at either the 3 or 9 o'clock positions with a brass punch. Some penetrating fluid might help.



_Modified by chickenfriend at 1:18 AM 5-29-2008_


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## chois (May 12, 2000)

I have had bad luck with aftermarket plugs fitting well. I recommend getting your replacements from VW.


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## 4ePikanini (Aug 29, 2007)

*Re: (chois)*

i agree. those plugs are access points in the casting process.
mine went and had them replaced. 
get the originals as they are an odd size and local dealers cant always get the right ones.
over here they are commonly known as welsch plugs.


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## ABA Scirocco (May 30, 2001)

*Re: (chois)*

Old frost plugs can be a bit of a pain to remove, but I've got a technique that's always worked fairly well for me, I take a SHARP cold chisel use to to puncture a slot in the frost plug, then at right angle to the slot, use a punch to drive one edge of the plug further into the block, that breaks the corrosion bond between the block and the plug and starts to angle out the plug then insert a large scewdriver into the slot and pry down toward the side where you punched. 
It had been many, MANY years since I last did this and I'd never done it on a VW, so before posting this, I tried it on a scrap VW block, it was a little tougher than I remember but then again, this frost plug wasn't rusted out like all those others I did years ago. Anyways, here's a picture illustrating (albeit poorly) the technique.


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## chickenfriend (Jan 31, 2005)

*Re: (chois)*


_Quote, originally posted by *chois* »_I have had bad luck with aftermarket plugs fitting well. I recommend getting your replacements from VW.

I have heard this as well, in reference to Meyle plugs. I don't know what manufacturer VW uses for their oem plugs, but that would be a suggested safe route.
Would also be a good idea to measure the plug diameter with a micrometer, and measure each plug.


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## Warp (Feb 17, 2007)

Thanks for all the replies. I'll check on the weekend and report back.
I hope I could do it before, but between my kid and work, it's very difficult.
Thanks for all the suggestions and pointers. I'll go OEM for sure when getting the replacements.
Thanks again!


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## Warp (Feb 17, 2007)

Well, bad luck for me.
It wasn't the freeze plugs but it's the head gasket between cyl 2 and 3, more less where the center freeze plug is.
Thanks for all the help. Car is being picked up next monday to the shop.
I just hope the dang head isn't cracked.
Leak is so bad it doesn't hold any water/coolant. It just drips right away.


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