blew a soft plug out of engine block

[AStutz]

I was just wondering if my headgasket could be leaking into my coolant system causing presure that would blow out a soft plug its the very rear plug at the back of the engine block. i tryied puttin in a rubber replacement plug but it came out also when i reved the engine has anyone else had this problem. my truck has 20,000 miles on it and is puttin out 45 lbs boost at the most and the first time it happend i was at wide open throttle.

 

[jwilliams3]

I think there is a TSB out for this problem.

Check with your dealer.

 

[Scrappy]

the test entails leaving the truck overnight with the dealer, they start it up and immediately put the throttle to the floor. I'm not sure how long they do this for but if it fails, they either replace the motor of buy the truck back. that is what I heard a while back.

 

[MMeier]

the test entails leaving the truck overnight with the dealer, they start it up and immediately put the throttle to the floor. I'm not sure how long they do this for but if it fails, they either replace the motor of buy the truck back. that is what I heard a while back.

For a leaky freeze plug??

 

[Scrappy]

I don't understand it either but that is what I heard a while back.

 

[ata]

On a series of blocks they machined the soft plug holes to big and thats the way they test to see if they will blow out. Cold engine block, the hole has contracted so the soft plug is not as tight in the hole.

 

[vciesielski]

Your Dealer has a larger replacement as part of the TSB

 

[AStutz]

i called the dealer and talked to the parts department i had to give them my vin number and they said they have to get the soft plug through cummins and then send it to me supposed to be like 10 thousanths bigger ?

 

[yycguy]

i called the dealer and talked to the parts department i had to give them my vin number and they said they have to get the soft plug through cummins and then send it to me supposed to be like 10 thousanths bigger ?

I would have taken the new motor

 

[jwilliams3]

You'll be good as new with the new cup plug.

 

[AStutz]

Well the new plug is on the way and i hope it gets here soon cause im goin to diesel nations at IRP this weekend what used to be the thunder in muncie event. i have the down pipe off and doesnt look to bad to get to just hope she holds. thanks for the posts guys

Adam

 

[Toxic]

old red it is good that it got fix ,if your tuck is puching more than 450+hp it will hapen again the plug will come out their is a fix call me or e-mail . I do not know if I can post the fix in this site thanx toxic

 

[Blakers]

On a series of blocks they machined the soft plug holes to big and thats the way they test to see if they will blow out. Cold engine block, the hole has contracted so the soft plug is not as tight in the hole.

This is ridiculous! There should never be combustion pressure entering the cooling system. It sounds like a blown head gasket to me.

 

[rbattelle]

This is ridiculous! There should never be combustion pressure entering the cooling system. It sounds like a blown head gasket to me.

That would be ridiculous; that's not what's going on here. Combustion pressure is certainly not entering the cooling system. As the coolant heats up it expands and pressure increases (I believe we have 16 psi radiator caps). That pressure blows the plug out from the block.



-Ryan

 

[Blakers]

That would be ridiculous; that's not what's going on here. Combustion pressure is certainly not entering the cooling system. As the coolant heats up it expands and pressure increases (I believe we have 16 psi radiator caps). That pressure blows the plug out from the block.



-Ryan

Ok Ryan, the first post indicated it did it when the engine was revved up. This told me combustion. Cooling system pressure is a different matter.



I never heard of this before this thread. Is this something only effecting 05's?



I wonder why they don't just replace the freeze plugs with some oversized ones? Or expand them a little before putting them in?



Blake

 

[nickleinonen]

you don't need combustion pressure to pop out a freeze plug... if you get your engine up to governed speed, you probably have around 50psi in the cooling system... that is after the water pump... once you get along to the return side, there will be less pressure [only what the system pressure cap would hold it at]. depending on location of the frost plug, the pressure of the water in the jacket behind it could be enough to pop it out if the block was improperly machined to fit plugs [why the about 0. 010" oversized plugs are avalable from post#8]

 

[rbattelle]

if you get your engine up to governed speed, you probably have around 50psi in the cooling system...

Wow, I didn't realize you could generate that much pressure with the water pump.



-Ryan

 

[nickleinonen]

i am not 100% sure what these engines will make, but i know water pumps can make pressure. . now if it is making say 50psi, and the head pressure is 16psi, the pump is only pushing 34psi... they work very much like a compressor side of a turbocharger... non positive displacment pump... it might not be as high as 50 psi with a pump this sized...



i know at work when testing for pump problems on the emd's, they [1 for left bank, 1 for right bank] can push 80psi in each pump if they are good, but those pumps are close to 2x the size of our stock turbochargers and weigh in at over 100lbs a piece

 

[Blakers]

I doubt very much if these water pumps make much pressure at all as they are just for circulating the water. I haven't had one apart, so perhaps someone else would know... are they centrifugal pumps with a volute that are made to make pressure, or are they just a circulating pump as used in most small block gas engine applications?

 

[SRadke]

Dragging this back to the top as I just blew the plug out of the back of my block. I'm wondering if I need to worry about the others or just replace the one that blew with the new oversized unit.



-Scott