losing coolant but no leaks and no overheating
 

ok picked up this 12 valve back in september of 2012 now ive added exhaust 4k springs afc mod 4inch exhaust and advanced timing. Now about a month ago i drove out to a buddy of mines and was doing about 70-80 and at the time, when i left my coolant level was fine then i get there to show him the truck i pop the hood and my coolant reservoir was almost empty but i didnt smell any coolant and didnt notice any leaks, so i fill the reservoir and level never changed for the next 2 months then today i decided to take the freeway home where i did about 70-80 again and my coolant level again was reduced. now before im attacked i have already looked all over on here and cumminsforum to see if anyone had this same issue. there are no leaks anywhere, im just hoping its not the head gasket. can someone maybe help me out truck doesnt run hot or nothing truck runs great nothing out the tailpipe either. any help would be greatly appreciated ty. mind u this only seems to happen when i go on the freeway i mostly do city driving with my truck. truck also has 218k miles

Is it making it into the crankcase? Check your oil level and see if it's rising.

Nope check my fluids religiously and haven't seen a rise in oil level at all :(

Ihad the same issue with my 01,24v,exact,run it a little harder than it would use coolant Turned out some body had the head off used the diegrinder doughnut gasket remover,the fire rings off the head gasket made indentations in the head,long story short get a pressure gauge to put on the radiator cap,check it cold &hot wouldn't doubt it is seeping when it hot,If replace it have the head checked for cracks&warpage. probably wouln't hurt to plane it,use ARP head studs on reassembly!!

Cool thanks a lot I hope that's the issue. But I sure hope he block isn't cracked :'(

pressure test it

yea... i'm not losing coolant but i'm definitely getting blowby into my coolant. I'm going to try torquing my head bolts down here eventually. Oil is not contaminated....

check your oil for milkshake and pressure testing your cooling system. that will narrow it down a bit.

If you are getting exhaust gasses in your coolant test it for pressure. If its building pressure the heads needs to come off and get checked at a machine shop. Also if you do plan on re torquing your stock bolts to see if that fixes the issue, you will need to be careful so you dont break on off in the block. After time the stock ones can become weak and easy to break