High Cooling system pressure and temp spikes...

[OCVeloMan]

Have an 06 6OH and am running an insight CTS as well as isspro EGT, FP and coolant pressure gauges. The truck has 56k and runs awesome, the gauges have me concerned. I was driving to the mtns and was running normal temps, 190 ECT and 197 EOT then all the sudden both jumped by around 30* within a couple seconds, i heard my fan kick into high gear (thermostat must've fully opened) and temps went down to like 170* after that. The engine was under load as we were climbing a steady 10% grade, not towing but it was pretty steep. This only happened once.

The truck pukes coolant on and off and I have replaced the degas cap twice with an autozone cap. It never pukes too much but i keep the coolant just under the min line. Oh, and I'm running EC-1.

My coolant gauge steadily works its way up to 18 psi under load where I sit most of the time between 16-18psi. I have no other normal symptoms... Not losing coolant, no smoke in exhaust, no leaking exhaust, no tea-kettle whistle, and my deltas never exceed 10.

Could I be looking at HG, EGR, or oil cooler failure? Main concern is my coolant pressure as I think the degas cap is the only thing holding the system at a safe pressure.... Reading on this site has me wanting to buy a bulletproof system and stud my truck. I would prefer to do a BP EGR cooler, stock Oil cooler and not have to do studs if possible. I'm 24 and on a tight budget! (saving for a house) Also want to get this done before i have a mortgage payment rather than ignore it and incur the cost when i can't afford it!

[Turbostang500]

Well i dont know much about the 6.0's but that sounds like a hg to me.

Way different engine but, my 302 had a bad hg but never burned ANY coolant. When I would build boost though, it was like a volcano out from around the rad cap.

There should be ways to test. On a diesel, can a shop test the coolant for fuel traces from combustion like on a gasser?

[dannyboy950]

I think you can feel safe on your oil cooler and egr cooler your deltas are quite good.
Your issue is some othe part of the cooling system, you may have a thermostat that is sticking allowing the coolant to boil in the block before opening. A weak clutch fan that comes on but way later than it should allowing the coolant to get too hot in the radiator.

Everything will depend on what the actual temps are when these events happen.

[OCVeloMan]

Originally Posted by Turbostang500

Well i dont know much about the 6.0's but that sounds like a hg to me.

Way different engine but, my 302 had a bad hg but never burned ANY coolant. When I would build boost though, it was like a volcano out from around the rad cap.

There should be ways to test. On a diesel, can a shop test the coolant for fuel traces from combustion like on a gasser?

No coolant in oil and no oil in coolant...

Originally Posted by dannyboy950

I think you can feel safe on your oil cooler and egr cooler your deltas are quite good.
Your issue is some othe part of the cooling system, you may have a thermostat that is sticking allowing the coolant to boil in the block before opening. A weak clutch fan that comes on but way later than it should allowing the coolant to get too hot in the radiator.

Everything will depend on what the actual temps are when these events happen.

Think it's more of a flash boil, not an undetected rise. Literally jumped 30 degrees in 5 seconds.

[OCVeloMan]

bump this!

[DREW34]

im having the same problem i heard it could be because my head gaskets are gone but at the same time it only pushes coolant out of the cap when im building alot of boost! could it because i have not changed the min and max line for the coolant and its just pushing out the coolant that it doesnt want in the system im constantly running a coolant temp around 185 to 190. help please!

[OCVeloMan]

Originally Posted by DREW34

im having the same problem i heard it could be because my head gaskets are gone but at the same time it only pushes coolant out of the cap when im building alot of boost! could it because i have not changed the min and max line for the coolant and its just pushing out the coolant that it doesnt want in the system im constantly running a coolant temp around 185 to 190. help please!

From my understanding, it will vent in normal situations until it reaches the "new" proper level (about 1/2") below Min line; however, it the system is running at 16 psi and constantly venting, there's an issue. I just don't know what that issue is as stated in my original post.

[DREW34]

Thats what i beleive its doing because the coolant level is still between the min and max level it all has not vented out im guessing

[DREW34]

really im just trying to get rid of the factor of my head gaskets being blow

[dannyboy950]

Both of ya a blown headgasket your pressures will rise rapidly and continue to rise as long as the engine is running. With the capoff running you can useually smell the exhaust fumes.

There is a test tool that mounts inplace of the cap and use a special fluid to test for combustion gases.

Note: Everyone makes one fo gas engines but there is a special fluid for diesel.
I haven't bought any lately but o'reilly and napa used to carry it. Be shure ya tell em its for diesel.