true--tried the cap last night since it was quick and didn't want to leave the wife without a vehicle today if possible. Will be changing the tstat today when I get home from work.

 

Well I'm pretty sure the tstat fixed it. 166 plus no puke and had heat. Got it to temp and no puke BUT had the dreaded spring clamp leak and it was a good one. Stoped at orielly and got a worm clamp and put a bit more coolant in. When I backed into the yard the fan ramped up to 800+. Coolant hit 218. Got home just in time. So tomorrow I'll get the worm clamp on and should be good to go.

 

When I did the t-stat on mine I had to go to a worm gear also. This wouldn't be the first time, 6.0's withstanding, that I've seen a t-stat stick closed till the temps are super hot and then pop open.

 

I sure hope so, On the clamp I told myself las4 time to get a worm clamp and change it since it leaked at first then too but stopped. Clamp is in hand now I can say It sure is nice having the Mishimoto tstst in. Gets to temp quickly. I now have 3 housings and 3 tstats lol.

 

Just fr chits and giggles pull the EGR valve and see if it's wet/damp.

 

Had not thought of it since the egr is deleted. Hasn't spit out any coolant from the tail pipe either----but I'll pull it and check. If it's wet I have a major problem!!!

 

So how would a non functioning thermostat, assumably stuck open, cause the system to puke? Why would that cause an increase in pressure above 16 psi??

 

Got me. I still will be doing a pressure test but changing out the tstat made things normal (tentatively) but I know what I'll need to do in the end

 

I may not be thinking right,but what's it mean if it is wet with a delete?intake gasket?

 

I honestly didn't think it could happen being deleted but if it was wet there has to be a major malfunction some where. Maybe since im on the app he didn't realize im deleted?

 

Worse case scenario,being deleted you could have an intake gasket leaking,or a cracked head.THIS is my knowledge on gas engines.now on 6.0s my knowledge is pretty limited on what would cause this.

 

I would think a head crack on these but I'm not up on the failures on these either.

 

Appears I'm good to go. Put a worm clamp on the tstat housing, filled it up, and took it for a spin. Stopped 3 times at different temps and no puke and no rise in degas. Once the tstat opened fully the coolant dropped to the flat in the bottle and stayed. One thing I am very certain with now is my truck is VERY sensitive to coolant level and my normal level is alot less than 1/8 below the min line (new max). I tell ya the mishimoto tstat is nice but hope it settles in a bit lower. 202 to 206 in 68 degree weather but unlike this spring when I swapped it out I'm leaving it in for the duration. The tstat I just took out was only a few months old.

 

If you read my post, I said a stuck closed t-stat that suddenly opens after the coolant in the block is super heated. This will create a sudden increase in system pressure. May not last long but the cap is doing its job when this sudden increase in pressure happens and the cap pukes.

 

Makes sense with the way it was acting versus how it is with the tstat change.