X15 coolant leak (weird)

[LTWON]

I have a 2020 efficiency x15 that I rebuilt not to long ago, quick backstory on this engine is I bought it with a almost fresh Cummins overhaul but do to the techs incompetence that rebuilt it it ended up spinning a rod and needing a crank. This was in August of last year, I rebuilt it myself (cut counter bore at Cummins, stainless shims .0145 liner protrusion etc) I am leaking coolant at the back of the engine, now it’s not a lot but enough to annoy me. It’s on the driver side rear of the engine and it seems as it’s an external head gasket leak but it’s dry around the head and block mating surface. Has anybody ever had a freeze plug fail and cause a leak on the head. It’s not something obvious but definitely annoying. Also this just started happening, the engine has approx 15k since rebuild. The shiny residue under the head has been there since rebuilding it, so that’s not it.

[Rawze]

trash or metal burr got between the head and block when the head was installed?.

An under-torqued head bolt?.

its anyone's guess.

[LTWON]

All possible, I triple checked the surface before it was set on, bolts were torqued to sequence to 150 then 300 lbs, I let them sit over night then did the 90* next day. Not getting any combustion or excessive pressure in the cooling system, it’s also been ran on a dyno for break in and they didn’t see any pressure in cooling system. Hoping I didn’t just get a bad gasket.

[tree98]

Is it a genuine Cummins head gasket from an actual Cummins dealer and not ebay/online somewhere?

[Rawze]

Its also an odd place to get a head gasket leak for coolant.

Was the head re-used?. It could be a crack.

[LTWON]

No it’s a brand new {after-market} head, unless I’m just seeing things and it’s not really coolant, shitty store paint that’s having condensation running down the block, I don’t know? I haven’t really been losing any coolant either but I see those streaks.

Also it’s a genuine Cummins headgasket from Cummins parts store themselves. I was just curious if anybody ever had an issue like this, it’s a first for me and it’s my 4th isx/x15.

[Rawze]

(06-10-2024 )LTWON Wrote:  No it’s a brand new {after-market} head, unless I’m just seeing things and it’s not really coolant, shitty store paint that’s having condensation running down the block, I don’t know? I haven’t really been losing any coolant either but I see those streaks.

Also it’s a genuine Cummins headgasket from Cummins parts store themselves. I was just curious if anybody ever had an issue like this, it’s a first for me and it’s my 4th isx/x15.

I can tell you that it would have been more common for someone to complain about an oil leak at the back right corner (intake) side of the head/block, but not a coolant leak. One of the main oil drains is there, and if the block is warped or pitted, they will tend to leak oil ... but not coolant.


- With an after-garbage head.. who knows though. Makes someone wonder what other after-garbage parts are on/in it?.

Was the overhaul kit after-garbage too?.

Any ways, there is 80% chances that you give it about 3-4 or so years (often less), ... and you will be on here complaining about having to replace that head again for one reason or another. I see it over and over around here.

Starting to sound to me so far that the whole thing is a big can of worms so far.

And then also.. is it de-mandated?... if so, then the program needs to be reviewed to ensure it is also not harmful as well.

[LTWON]

lol. Seriously rawze? What’s Cummins? Not Chinese garbage? Constant dropped valves and seat problems? I have yet to see {this brand} fail, unlike factory Cummins heads. Sodium filled valves, better seat etc. no the bottom end is factory Cummins. Can of worms lol.

Demandated….. your tune.

[tree98]

(06-10-2024 )LTWON Wrote:  unless I’m just seeing things and it’s not really coolant

Try pressurizing the cooling system with shop air and see if it leaks. Might have to be up to temp for it to leak though so maybe do it as soon as you park it for the day.