Coolant loss -- headgaskets or EGR cooler?

[superswamper003]

So ive owned my truck (05 lly) for over two years now, and I have had the "low coolant" come on the dash a couple of times, soft upper rad hose and no pressure in degas bottle. Although there is a little bit of diesel soot inside of it. I crawled under the truck just a little while ago and there is a slight coolant leak on the bellhousing on the drivers side just next to the oil filter area. I will pressure check the system at work tomorrow, and look a bit more once its on a lift.

The truck has given me absolutely no problems since i have owned it, and there is absolutely no white smoke coming out of the exhaust. The fact that there is slight diesel soot in the degas bottle makes me believe the head gaskets are going but I just want to have some opinions on wether it can possibly be a egr cooler? Thanks in advance :thumb:

 

[Chevy1925]

Egr cooler means it would be wet on top of the bell housing too

I would say a weeping HG to the outside (original hg were known for that) or the oil cooler elbow is leaking.

 

[Dozerboy]

If it was leaking to the out side he wouldn't have soot in the coolant would he?

My HG took a long time to really show itself. I had soot in my degas bottle at around 100K when I first flushed my coolant. Then at 170K I was starting to see more of a hard hose after removing my EGR. It really started to show itself after a ton of repeated hard pulls in 5th over 500hp doing some lag test. Now after a 3K mile trip pulling a 10k camper I'm starting to see pin head sized bubble in the degas bottle. I can't believe it hasn't really let go yet. I almost wonder if it's a cracked head or something.

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[superswamper003]

What i thought to be a coolant leak turned out to be nothing at all.. Or rather, some old hardened coolant from a long time ago just resting on the bellhousing. I couldn't find a leak, which i thought I had had before. I figured if I cant see a leak, and the hose doesnt get hard, I think the truck is ok for now. We will see, thanks again

 

[Chevy1925]

If it was leaking to the out side he wouldn't have soot in the coolant would he?

My HG took a long time to really show itself. I had soot in my degas bottle at around 100K when I first flushed my coolant. Then at 170K I was starting to see more of a hard hose after removing my EGR. It really started to show itself after a ton of repeated hard pulls in 5th over 500hp doing some lag test. Now after a 3K mile trip pulling a 10k camper I'm starting to see pin head sized bubble in the degas bottle. I can't believe it hasn't really let go yet. I almost wonder if it's a cracked head or something.

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mine was dirty but i think it was more from crap accumulating over time. ive seen alot of people thinking a dirty bottle = soot. never had any symtops other than low coolant every 2-3 weeks. never dripped on the ground or pissed anything out anywhere. back in the days when i had an edge w/ attitude :roflmao:

 

[NC-smokinlmm]

Same old story from every LLY owner "not mine, it's the egr cooler" lol...

It's all LLY, it's got blown gaskets. Deal with it or it will eventually wipe out the heads and block and you will be going with an unknown engine...

 

[IOWA LLY]

Be sure to pressure test the system and check for leaks before assuming anything. I’ve seen a ton of trucks that have pinhole leaks in the hoses going to the turbo. Especially the one going from the coolant crossover pipe back to the turbo on the driver side.

But unfortunately head gaskets are common. On ALL generations of Duramax engines. However, blown head gaskets almost always cause a hard upper radiator hose. Since you don’t have that issue I’d be looking for leaks elsewhere.....


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[duramax on fire]

Oil cap any condensation on it after hot?

 

[superswamper003]

Oil cap any condensation on it after hot?

I will check that today when I get home from work

 

[Chevy1925]

Oil cap any condensation on it after hot?

this isnt always a good determination. your oil will naturally hold moisture, specially this time of year with humidity through the roof in 90% of the country. Soon as the engine gets hot, the oil starts to steam the water out and can show a milky substance or water drops on the oil cap. The oil cap on these truck is also harder at showing this old way of checking for moisture as its not on the valve cover like older engines use to be and that is where a majority of the moisture travels, up and out the PCV. there is just a small section open at the front of the oil pan that the front cover is open to and alot of curves in teh front cover to catch moisture.

 

[superswamper003]

I need to get my hands on a different pressure tester than I will see.

Well I had the cooling system under pressure for around a half hour and it held pressure. Happy me

 

[duramax on fire]

Yes it's not a for sure sigh checking the oil cap. But it's just another piece to the puzzle. And if it was covered in milky white crap. Well then..... plus here in dallas I've never seen condensation on a hot motor.

Water pumps can hold pressure all day and never drop until you start the truck. But I don't think a water pump can cause a leak that far back. But I am currious how many miles on it?

 

[NC-smokinlmm]

This thread makes me want to :barf:

Like an LLY :rofl:

Seriously, now that I got that out of me... We all know that the HG's are toast, it's an LLY.

 

[superswamper003]

Yes it's not a for sure sigh checking the oil cap. But it's just another piece to the puzzle. And if it was covered in milky white crap. Well then..... plus here in dallas I've never seen condensation on a hot motor.

Water pumps can hold pressure all day and never drop until you start the truck. But I don't think a water pump can cause a leak that far back. But I am currious how many miles on it?

That leak i thought i had ended up just being some old hardened coolant possibly from a long time ago.. Im not sure, but there is no leak that I can find. The truck has 269k miles.

 

[duramax on fire]

That leak i thought i had ended up just being some old hardened coolant possibly from a long time ago.. Im not sure, but there is no leak that I can find. The truck has 269k miles.

Well you stated that you've only put coolant in twice correct? Two years? **** it I wouldn't worry about it until it shows its ugly head. That's just me. Truck could be totaled tomorrow by a bad driver. Just how I live.

 

[duramax on fire]

This thread makes me want to :barf:

Like an LLY :rofl:

Seriously, now that I got that out of me... We all know that the HG's are toast, it's an LLY.

And sorry I don't agree. Head gaskets may be gone but all you here about on these forums is the bad. I've got two buddy's with 300 plus on llys no issues. And a buddy with 189 on a factory lb7 bought new with no injector issues. Never been touched to this date.

 

[superswamper003]

Well you stated that you've only put coolant in twice correct? Two years? **** it I wouldn't worry about it until it shows its ugly head. That's just me. Truck could be totaled tomorrow by a bad driver. Just how I live.

That is correct, 2 or 3 times topping off the bottle when the coolant light came on.

I was really curious what the pressure test would result in, but the cooling system held perfectly.

Thanks

 

[IOWA LLY]

And sorry I don't agree. Head gaskets may be gone but all you here about on these forums is the bad. I've got two buddy's with 300 plus on llys no issues. And a buddy with 189 on a factory lb7 bought new with no injector issues. Never been touched to this date.

He’s just upset cuz he’s worried about when his LML is gonna puke it’s pos CP4 pump into his injectors and leave him stranded.


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[duramax on fire]

That is correct, 2 or 3 times topping off the bottle when the coolant light came on.

I was really curious what the pressure test would result in, but the cooling system held perfectly.

Thanks

I would look hard at the water pump. It's hard to get a mirror down there but look at the weep hole and see if it's leaking. If it's never had one your past due lol

 

[NC-smokinlmm]

This has been discussed...

About 10 years ago...

My LML is just fine buddy. It has a 100k warranty and its stock so why would I worry one bit? :cool2: