My degas bottle has been puking a little coolant out of thr cap since the weather has warmed up. When the engine is cold the anitfreeze is dead between max and min marks. The coolant is less than 1 year old, it is conventional green coolant with SCA additive and 50/50 mix. Looks good on test strips. Anyhow, im losing a few drops of coolant everytime I drive it makes a tiny puddle beside the battery and under the cap.

I have replaced the cap with a new 16# stant cap from Advance Auto, I have washed out the intercooler and radiator. The temp gauge never shows over 1/4 above "cold" my oil temps are getting up to 210-215 deg when driving at interstate speeds. Which concerns me as I am not hauling anything. The degas bottle is almost all the way full after a 5-10 min trip the antifreeze has expanded? enough to go from marks to top of bottle.

I opened the cap as soon as I got home today and I had no pressure even though the truck was warm. The antifreeze in the degas bottle wasnt too hot I could stick my finger in the water for a sec without getting burned. There was coolant puked out again.

So do I have a overheating problem? Cavitation problem? Blockage? Something blown? Or just another crappy radiator cap?

Any help greatly appreciated.

No water in oil. No fuel in coolant, no bubbles in coolant with truck running and cap off. No white smoke, etc. Just higher than normal oil temps and puking coolant.

 

Do you have the "long stem" (stock) Powerstroke thermostat installed?

Pop

 

I have no idea, never had the t stat out.

 

I wonder if your thermostat is opening, or just the bypass action is all that allows any circulation at all.

Think I'd pull it and put it a pan of boiling hot water and watch it.

Pop

 

I am going to drop the level in the degas bottle to the min line, because hot coolant is sitting on the cap when it is at operating temp. Im going to install a t fitting in the small line on the side of the degas bottle and hook up a pressure gauge to it and monitor the pressure to make sure no air is getting into the system when i push 15-20# of boost through the engine. Hoping its not a head gasket or injector cup. Im also going to put a strap on temp probe to the upper rad. hose and to monitor temps and go from there. That should cover it. Then I will know which direction to go. Sounds like a good plan anyhow.

 

OK. Guess you got a plan figured out.

Hope I gave you some good thoughts along the way.....

Pop

 

Subcribing,

 

once it has warmed up and been run at temp for at least 10 min turn it off and get your hand between the fan blades and feel the core in as many different spots you can if it has a blockage parts of the core will be noticably cold to the touch. usually in the middle right in front of the clutch of the fan. a blocked rad partially blocked rad can cause these symtoms..

 

The results are in......
2 bad radiator caps.

I put a t fitting in the small 3/8" hose on the degas tank. Hooked up a old set of my refrigeration manifolds to the fitting. Added nitrogen, the first cap let off at 1 psi the second cap let off at 5 psi. The caps let off at different pressures everytime I tested.

Anyhow went to Ford stealership and bought a $15 dollar oem motorcraft cap. Re tested system. Held to exactly 16 psi. Took cap on and off several times each test was a consistant 16 psi. Routed gauges into cab and went for a test drive. After warmup the system was holding between 5 and 6 psi. I then proceeded to drive the truck a little harder pulling some big hills and getting 10-12 # boost. No pressure difference in degas bottle held a consistant pressure.

Came home let truck cool. Pulled upper rad hose. Put a 2 wire thermistor in hose, hooked hose back up, hooked thermistor to my electrical meter, took for a drive, coolant temp running 195-199 deg. Oil temps running 202-208. This is with a/c on and ambient temp of 93 deg, in traffic. Im still a little concerned with the oil temps but I cannot find any solid info on what the oil temps are supposed to be.

No more puking coolant and the oil temp is down a solid 8 degrees from last weekend when I drove the truck and it was only 84 deg ambient last weekend.

A nice improvement.

BTW do NOT buy any junky radiator caps from the chain stores, one was a Stant cap the other a Murray. 5 dollar caps are exactly that, 5 dollar junk caps.