Puking coolant

[justin.loehlein]

So, I found a coolant leak from the rubber cap near where the lower heater hose attaches to the block. It was dry rotted, thankfully I caught it while it was just dribbling coolant every now and then. I replaced the rubber cap and ran the engine with a radiator funnel until it got hot, let it cool, and then topped it off.



I went for a drive to make sure everything was okay and ended up puking a bunch of coolant everywhere. The was radiator only ~2/3 full after I let it cool down and opened it up. It looked like it had exploded out of the overflow bottle. The good news is that I don't see any leaks anywhere. I checked the thermostat and it starts to open at 180, but doesn't get fully open until around 200. Not sure if that's normal.

Anyways, thoughts on what could have caused this and how to avoid it? Maybe there was still some trapped air in the system? Also, I'm planning on just replacing the thermostat and seal since I have it out. Any tips on where to get one? I've seen a few different types. As much as I'd like to go to the Cummins dealer, they're 90 minutes away and only open when I'm at work. I have other vehicles to drive, so I don't mind waiting for parts in the mail.

Thanks in advance for the input.

-Justin

[ellis93]

Buy a cummins stat.....don't look back. The others are not worth the time and effort.

[dmerlin25]

Not finding a leak is not good news. The last time a vehicle did that to me it was a blown head gasket and I was was blowing exhaust into the water jacket. That was on a gasser but same principal. It would only do it when the head heated up. I certainly hope that isn't your problem.

[justin.loehlein]

Yeah, hopefully not a head gasket. I didn't see any bubbles coming out of the radiator when I was running the truck to fill it.

Which Cummins thermostat do I get and do you all have a good online source for parts? I found Diesel Parts Direct through a Google search, but they list 10 different thermostats.

[ellis93]

I don't have a clue which one......I've always ordered from cummins over the phone and it was sent to me. They'll need the engines serial number off the data plate.

I second the hg thing......it could have been an air pocket tho. Steam does some weird stuff.

[ofelas]

Cummins 180 thermostat 5292738 (3972071) + seal 3923331
or Cummins 3802968 stat & seal kit

Yeah, hopefully not a head gasket. I didn't see any bubbles coming out of the radiator when I was running the truck to fill it.

Which Cummins thermostat do I get and do you all have a good online source for parts? I found Diesel Parts Direct through a Google search, but they list 10 different thermostats.

[justin.loehlein]

Perfect, thanks. I didn't realize the Cummins dealers would ship parts. How convenient! I ordered the kit through them. After years of frustrating and expensive interactions with car dealerships, I had trained myself to buy all my parts online. Dealing with the Cummins dealer was great though. Replaced the thermostat this weekend. No issues on a test drive, I've got my fingers crossed.