So I drove to the store Saturday (quick trip) and thought something was a miss because the heat wasn't blowing heat until the engine temp got up to 166. When I got to the store I popped the hood and had some puke. Got home and it has been sitting since. I just went out and started it and let it warm up a bit to see if the heater would blow hot. The coolant level was normal and had little pressure in the bottle. Well it got up to 140 and still wasn't blowing warm. I got out and looked at the coolant and it was POURING out of the cap--wth. I turned the high idle off and the pouring stopped. The coolant was already at the top of the bottle and the heater line wasn't real hot although was warm and the hoses were tight to the radiator. So could this all just be from a bad cap?
I'm pretty sure it isn't but hey a man can hope.

 

If you are not showing other signs such as high temp readings, fan running it's *** off.
I would suspect the cap went bad. Any gas bubbles observed in the degas bottle?
Altho now you may want to do further testing now.

 

I haven't had it over heat at all. No where close. Haven't noticed any bubbles either. But the way it was coming out the cap scared the crap out of me. It wasn't all around the cap either just the very front part and was like a waterfall not a spray.

 

You might also consider a closed sticking t-stat.

 

Didn't cross my.mind at all. Was planning on putting the Mishi back in too.

 

Sounds like it is time for Bill's Hero Kit! LOL. Pop the hose and guage on and see what the cooling system pressure is and how fast it gets there.

 

You say just before you started it up the second time that there was little pressure in the system. This tells me you have an issue with the cooling system and not HG's. Maybe the cap.

.

 

Ok so I put a new cap on and started it up. Got to 146° then puked just like last time just not as much then stopped and didn't puke all tge way through 192°. Now as far as heat--same thing no heat until 160° or so and only while high idle on. As soon as I flipped the high idle off it would start to get cool again until the temp got to 190° then it would stay warm. I also noticed thst with the high idle on the coolant level would fill the entire bottle until it got to 190° then it would stay close to the max line.. As well when I turned the high idle off the coolant would drop to almost the max line. It's acting like it has air in the system when cool and takes getting the tstat open to clear it? Also it was very strange to me that the puke came out of the exact same spot from the cap as it did the previous time. I wonder if the bottle may be messed up in that place as well. I'll be changing the tstat tomorrow hopefully and will put a gauge to it this weekend hopefully. Needless to say I won't be driving it until then. Oh and fan never ramped up. Didn't go over 420 at idle and was in the 300s at high idle.

 

Did you check the bottle for a crack at the spot where it is leaking. You may have a hairline split or something with the threads on the bottle.

 

Will have to rake a good look at that and see if it's cracked for sure.

 

I didn't have major puke like that, but a worrisome amount, especially after a hard run. My truck is studded with a bpd egr cooler, so i was hoping it wasnt improperly done studs. Upon closer inspection, my degas bottle had a bunch of hairline cracks, especially on the underside of it. I switched it out for a dorman degas bottle and still not a bit of puke 3 months later. If you still have the original degas bottle in there, it wouldnt be a bad idea to change it. Costs less than $40

 

Yeah this bottle is a dorman. Been in since march I think. Changed out the original due to the sealing surface for the cap was bad. It would make since it having a crack at the threads on mine since it's venting in the same exact place as the other cap. Well see. Will probably get a new one again since I'll be drained down when I put the 200 degree tstat back in.

 

Have you tried letting it warm up with the cap loose and then tightening it? It would let it run with lower pressure to start with and possibly let some of the air pockets work their way out if you have any. If it still builds enough pressure to puke, even with the coolant not being overfilled, i would start to worry a little. Your truck is not studded, correct? Any white smoke under hard acceleration/high boost? Internal radiator blockage is a possibilty, although unlikely. Coolant/oil delta? EGR deleted or upgraded?

 

No smoke other than condensation on cold mornings, no egr, not studded.

 

If your going to replace the t-stat anyway, why not do that first so that you can determine what if either was the fix. When you do more than one thing at the same time you never really know what cured it.