Doesn't the plug expand when it gets hot though?

Has anyone blown a freeze plug in an '05, '06, or '07 that we know of? It seems like the '03-'04.5 trucks are usually the ones having this problem.

 

I had this problem back a couple years ago. High rpm, almost warmed up truck, and rear plug blew out. I built a plate to cover the rear plug and installed the plate and a new rear plug, no more problems. My understanding of the problem is that the water pump is made for high volume at low rpm so that pulling heavy loads and such at 2000rpm, there is plenty of coolant flow. I read back then that the water pump at high rpm was capable of putting up 80psi of pressure. The only plug that is really hard to get to is the rear one which is the most common to blow. Just my opinion, but I don't believe it has anything to do with coolant heat around #6 increasing localized coolant pressure. Pressure in a system like this equalizes way too fast for this to occur. If anything, it could be localized heat allowing the block to expand slightly faster than the freeze plug due to dissimilar metals. While I agree that a pressure regulator of sorts is the ultimate solution, many have had zero problems with just a metal plate bolted over the rear freeze plug to keep it in. Another solution to use in addition to the plate mod is to trim a couple vanes off the water pump. IIRC, there are 5 vanes and I trimmed off 2 to reduce system pressure. I have towed 10,000+ and have had no problems with overheating.......been over 2 years.

In summary, chips and performance mods that allow higher than stock rpm, and allow rpm to climb much quicker than a stock truck are the real culprits here. Although I imagine it has happened to a bone stock truck, I have never read of it.

Waylan

 

I think its the other way around before I blew mine not many had ever heard of this on a 03, thin it seemed like the 06s built more pressure or likly for them to blow

 

Yes, but that 60psi gauge wraps to the max! 100psi would've been a better choice for 3500+RPM testing.

Unless you drive an auto with a light foot, you won't be able to keep the system pressure below 30psi... and as I posted earlier, there's hundreds of pounds of pressure on the freeze plugs at rated RPM.

Again, an engine brought to operating temperature before having max power demanded from it is no guarantee from blow-out... and yet again this is only going to be an issue with BOMB'd trucks.

We don't call them supporting mods for nothing!

 

last time we talked about this it was a 06 truck that had blown the rear plug...fixed the rear plug and then blew the side plug by the turbo..either way if you bomb your truck you should have a bypass or BOE....it's cheap insurance IMHO

 

I don't think rpms had much to do with mine blowing out. It happened below 2500 rpms, and over 200*.

 

I know at least two 05s that have blown rear freeze plug.

 

Kerry,
You are lucky, and stop saying that!!!! You are making me nervous for you , I can't believe the good luck that has been on your side since before we last discussed this.




I agree, the plugs are blowing right before the T-stat opens or as it starts to open!!




From what I have seen these motors are not usually very happy much over 200*

I would say that high RPM is not the problem but maybe the root of the cause

High RPM = Excessive heat build up = High coolant pressure and you know what comes next.............................PoP there she blows


There is a lot of great info HERE

 

Maybe someone could get Fluidampr to make some "power pulley" versions of the Cummins crank pulley. Something like the undersized crank pulleys they sell for the Ford and Chevy gassers that reduce accessory rpm.

 

Knock on wood, I been lucky so far. I don't reckon that BOE would fit on a twin turbo setup would it?

 

Sweet pic man!

What type of filter and box is that? I like the idea of having a heat shield between the filter and turbos/manifold.

 

There is almost no underhood heat upfront or down low when the truck is moving...it all against the firewall and the rear of the hood.

 

That sounds logical, but I've seen intake air temps up to 136* at the end of the 1/4 mile. That's with the twins and ambient temps around 85*. With the AFE filter/box the highest I saw was 118* at the end of track, with ambient temps around 90*. Seems like the heat shield might have made a difference.

 

I think it has more to do with the ram air funneling effect of damning up cool air from the front than heat moving forward...

RAM air is ideal...

I wish I could make a 6" Scotty type air can for my twins...that thing worked the best of any intake I have ever used.

 

Possibly, but the root of the problem is not the speed that the water pump turns. As stated before the problem occurs when the T-Stats are closed, therefore no water is being circulated through the block.



The excessivly quick heat build-up, which comes from more/higher RPM is when the problem arises.