Diesel RVs: Re: [diesel_mercedes] Re: Detroit engine seizure OK lets talk

When I bought my Dodge, it had a couple of rubber plugs in it, I got it a new rad cap which shortly caused the rubber plugs to blow out - on the freeway, of course - and so I learned that the B6 Cummins uses funny sized freeze plugs you can't get at the Autozone.. I had to go find a Cummins shop and had the whole lot replaced.

bk

--- On Sun, 3/13/11, BStromsoe <bstromsoe@yahoo.com> wrote:

From: BStromsoe <bstromsoe@yahoo.com>
Subject: Re: [diesel_mercedes] Re: Detroit engine seizure OK lets talk
To: diesel_mercedes@yahoogroups.com
Date: Sunday, March 13, 2011, 3:00 PM

I appreciate all the freeze plug, info - but, after 55 of years of driving 40 or 50 cars and trucks all over the country - I don't recall ever having a freeze plug popping out, unless I was removing it myself for some reason. My plugs have all been pounded in nice and firmly. I may have had one leak a dribble once upon a time. My guess is that passenger cars have a hard time popping loose freeze plugs, but maybe trucks and industrial engines are another story. In conclusion, "freeze plug" is a pretty sorry name for this thigamajig.

brian from la verne, ca

From: diyernh <diyernh@comcast.net>
To: diesel_mercedes@yahoogroups.com
Sent: Sun, March 13, 2011 8:07:22 AM
Subject: Re: [diesel_mercedes] Re: Detroit engine seizure OK lets talk

I don't think thermal expansion was the issue. Brass has twice the thermal expansion of iron. Over 100F temp drop, a 2 inch brass plug would shrink .00104". The Iron would shrink .00059 inches. difference of .00045". The plugs are cupped and over sized when you put them in. The thin brass plug wouldn't be more than a few degrees different from the cast iron hole/water. I think someone was telling you a story.

Also, when it is this cold, there is no pressure. You need to heat up the engine to get some pressure.

I believe someone at some time may have not had the correct mix of antifreeze, causing the ice expansion to push the plug loose. After it was loose, it just took a little while longer to push it out.

Carl

On 3/12/2011 8:00 PM, john public wrote:

I've experienced the situation where freeze plugs have fallen out from an engine. Years ago I worked on a line crew and the freeze plug on the IH motor started to leak; we'd have to add water as we used the truck. Eventually it leaked faster than we could add water and the truck would overheat if we didn't shut it down. The cause of the failure was operation in -30F weather; the engine heated unevenly and the plug heated more slowly than the block. I doubt the plug was that cold when it was originally installed.

--- On Sat, 3/12/11, diyernh <diyernh@comcast.net> wrote:

From: diyernh <diyernh@comcast.net>
Subject: Re: [diesel_mercedes] Re: Detroit engine seizure OK lets talk
To: diesel_mercedes@yahoogroups.com
Date: Saturday, March 12, 2011, 4:34 PM

the real purpose of freeze plugs is for casting the engine. The hollow passages inside the engine need to be molded with sand. The connections of the sand mold are through the freeze plugs. they bore out the holes and push in light sheetmetal plugs in the holes. There are usually one on the block, below the heads, between each cylinder. some may be on the front/back of the engine also.

They call these freeze plugs, thinking that if water freezes in the engine, it will push out the sheet metal plugs, avoiding damage to the engine casting. They may work that way sometimes, but usually the engine is destroyed. Don't trust them.

Every cast engine will have "freeze" plugs.

Carl

On 3/12/2011 12:11 PM, c24052000 wrote:

doug, What is the purpose of the freeze plug? where is it located?
Do I have one on my 300sd?
Thanks
Chuck