09 Maxxforce DT coolant leak

Matt Saunoras · February 16, 2019

This truck has had issues since I started. Last year it ruptured an EGR cooler and I replaced both of those. The truck is still losing coolant which it's entirely possible this has been the issue the whole time and the cooler rupture was effect and not cause.

There is dried coolant crust all over the rear of the engine and bellhousing. It never drips a drop on the ground. The seepage starts near the rear of the engine between the head and block. Do any of you guys know if it's possible for a head gasket to leak coolant externally on a DT?

I can't work on this truck until the snow stops but I would still like to get some info before I just tear into it.

Bruce Amacker · February 19, 2019

This is the rear of my 2005 cutaway engine, yours should be the same. The big hole in the lower left is coolant, the other three are head bolts. I don't remember what the small hole in the lower right is, maybe an oil galley plug or something. They're not prone to blow head gaskets but that doesn't mean yours isn't leaking. Do your obvious diag.

Good Luck!

Matt Saunoras · February 23, 2019

Bruce thanks so much. So it is possible this is a headgasket leak or a flaw in the block or deck. I won't be so reluctant to tear into this thing now. I've been over this engine multiple times looking for anything that resembles a coolant leak, it's definitely the rear of the engine. Next time I have the doghouse out I'll snap a pic.

Anything you can think of to do preventative while this engine is apart? It only has 30k miles but not sure about hours. Oil rail seals anywhere prone to leakage?

Keith Browning · February 23, 2019

I don't know what type of gasket this engine uses but I recently had a 5.4L with an oil leak in the rear of the head. I got it apart and checked the block and the head both were perfect as far as condition and flatness. The laminated steel gasket was too with the exception of the printed sealant which was flaking off easily compared to the rest of the gasket.

Fucking LOVE cutaways! :rockon:

Bruce Amacker · February 25, 2019

On 2/22/2019 at 10:28 PM, Matt Saunoras said:

Anything you can think of to do preventative while this engine is apart? It only has 30k miles but not sure about hours. Oil rail seals anywhere prone to leakage?

Most guys won't pull the doghouse to do a HG or even a major O/H. Is that 30K since O/H or since new? Definitely need the hours and info since last O/H.

Flaws in the block or head are rare, probably just a HG.

I would do a compression test before investing that kind of time into it before teardown, I can loan you the adapter if you want. The "pucks" above the injectors are really trouble prone, I'd reseal or better yet replace them while you're in there. Last check they were about $25 each, they take a special hex wrench you'll need to buy, make or borrow. A new ICP wouldn't hurt as it's under the valve cover.

Do you have OnCommand? Shoot me your e-mail address and I'll send you some info, bamacker@aol.com

Matt Saunoras · February 27, 2019

I'll have to check the hours but it's got 30,000 miles on it total. Are the oil rail pucks by chance the same size as a 6.0? I have that tool.

Bruce Amacker · February 27, 2019

Nope, different tool, and beware that some WSMs incorrectly have the 6.0 PN in them for the DT pucks. You probably wouldn't have a hard time making a tool adapter out of a big hex nut but the tool has come way down in price:

ZTSE4725 High Pressure Rail Adapter Socket Alt

PS The torque spec on those is not in the WSM but in a bulletin, it's 150ft/lb.

exmod110 · March 1, 2019

You can make a tool out of the correct size nut hogged out to fit over the nipple if you dont have quick access to the tool. weld 2 together to give a good amount for the socket to bite onto. tool # ztsw4723

Matt Saunoras · October 24, 2019

Okay so a little late to update but I finally got around to working on this thing. The head is off.

The leak is originating from the right rear corner of the headgasket. In this area on the deck of the cylinder head is a stainless steel freeze plug. I think my leak is around this plug.

Also in the block deck is some kind of round machined recess, I don’t know if it’s a plugged passage or what but you can see it in the cutaway picture Bruce posted. I was wondering what this is?

Also I would like to mention that the rear 2 cylinder liners in this engine are wiped out. No crosshatching, rust staining, I’m assuming this is from when the coolers failed.

I will get some more pics up later

Matt Saunoras · October 24, 2019

Okay I’ve been looking at this thing all day scratching my head. I knew this freeze plug looked fine but I was insistent the leak was in that area.

5 minutes ago I just so happened to look at the head a little closer and found a crack all the way from the exhaust port, up through the bolt hole all the way to that freeze plug I thought was leaking.

Hard to see in this pic but you can see it towards the edge

JoeR · October 25, 2019

Nice find!

Matt Saunoras · November 6, 2019

Working on an in-frame rebuild currently. Using new sleeves, pistons, rings and rod bearings. Obviously a new head also.

The guy at international says the pistons and cooling jets are a new design for better cooling. Is there a bulletin for this?

Bruce Amacker · November 7, 2019

I'm glad to see you're using OE parts.

Wise men would hang a set of new OE injectors with this job, it's common to have wonky injectors take out a cylinder on this engine. I know it's big money but you've already blown the budget.......

Did that info I sent you help?

Matt Saunoras · November 19, 2019

It did but for some reason drop box loads really slow for me. I haven’t looked into it yet though. The proper service info is extremely valuable for a job like this.

The inframe is back together and running good but I’m having an issue with the voltage meter on the instrument panel. Key on and it pegs way past 16v. Never changes. It’s charging just fine at14.2. I’m looking for a wire I left loose but I’m coming up empty.

edit - found it. One positive wire to the body controller I left off