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Coolant leaking from cylinder head


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Recently, while my wife was out shopping, our 98 cadillac Deville overheated. I found what I though was the problem, the camshaft pulley was bad and the water pump belt fell off. So, naturally i replaced the pulley's, the water pump and the thermostat. When I finished I started to fill the car up with water to test for leaks and this is what I found. My question is, is this a expansion plug and if not what is it?

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I would think you could purchase a welch plug and replace the plug but the trick is access to the existing plug to allow for removal and installation. Did the current plug rust away?

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Wow that is a first as far as I can remember. I have two heads sitting on my shelf. Ill take a photo of the area so you can get a closer look

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

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Blew the expansion plug out ??? Haven't seen that one either. Easy fix if you can get to it. probably will require the removal of the cross-over which is a PITA, ask BBF ^^^^^^^^ he's done em in the car!!

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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One thing to look for is the hole in the block, once the old plug is out. There will likely be some water corrosion to go with the rust on the plug.

I believe that there are types of Permetex or other sealants that are intended for casting plug sealing. I don't know how good a fit you must have for aluminum. BBF will know all this.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Thats the first freeze plug I have seen fail on one of these. could the coolant have froze? that would cause that to happen. Could also explain the pulley damage. If the pump was froze it likely would not have turned and something has to give

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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The best Permatex is the non-hardening kind for expansion plugs. Make sure the area is dry so lower the coolant level as much as possible, use brake cleaner on a rag to remove any coolant oil etc.. apply a liberal amount to the plug and install evenly and flush with outer edge.

My 2 cents worth....

John

THERE IS ALWAYS ENOUGH TIME TO DO THE JOB RIGHT - THERE IS NEVER ENOUGH TIME TO DO THE JOB AGAIN !!!

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Thats the first freeze plug I have seen fail on one of these. could the coolant have froze? that would cause that to happen. Could also explain the pulley damage. If the pump was froze it likely would not have turned and something has to give

That is a good point! I clicked like for ya

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The best Permatex is the non-hardening kind for expansion plugs. Make sure the area is dry so lower the coolant level as much as possible, use brake cleaner on a rag to remove any coolant oil etc.. apply a liberal amount to the plug and install evenly and flush with outer edge.

My 2 cents worth....

John

If the hole in the block is not clean, non-hardening sealer won't fill in the rough spots. The hole would need to be reamed or the rough spots filled for non-hardening sealer to work. But maybe we should wait until the plug is out before we worry about what we haven't seen yet. It could be something as simple as a damaged plug. Someone mentioned the possibility that it could be pushed out, although it looked normal in the video. I couldn't see the huge gap where all the water is coming from, though.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I watched the video a few times and it looks like the freeze out plug in the head is leaking, is that correct? Here are a few close ups. You will notice on one head the cam pulley is removed and in the other head there is no intake cam for locational perspective.

2016-04-11%2021.10.47_zpsndf5zp4l.jpg

20160411_205248_zps6jlly9sb.jpg

20160411_205307_zpsilp1yqmc.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 3 weeks later...

Every local parts store has the freeze plugs in stock. When the freeze plug blows out its from extreme overheating and lack of water. I have seen a couple engines missing the freeze plug and one of those engines had a cracked head. That's the ONLY cracked head I have ever seen on these engines.

Edited by barczy01
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Well, they say that nothing is truly foolproof, because fools are so ingenious.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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