Recently purchased a 2006 f250. I've notice coolant around the underside of the coolant cap. The warm air from the cab heater did turn cool for a few seconds a time or to. Replaced the cap, ran 2 tests at the degas bottle.

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But anyway, one test consist of pulling air from the bottle, the air/gases are pulled up through a liquid and if the liquid changes color it's due to the combusted gas in the coolant system. No change in the color.

2nd test was testing the pressure in the coolant system. Pulled up to the shop after a 30 minute drive, removed the cap, screwed the pressure tester on, started the truck and let ut idle. No pressure after a 10 minute test time. Now from what I've read it shouldn't build up pressure if the truck is at running temp.

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I will try the "T" valve test next.

Here is a pic of running temps I have previously uploaded. If you guys don't care, let me know if you see something that is off. Also I don't know how to size the pic so sorry it's oversized.

Temps are at operating levels.

 

Odds are it was just the degas cap, not uncommon.

I would think about a new tstat if that is running down the road. It's running a little cool IMO.

Would also keep my eye open for a good deal on an OEM air box.

 

Figured someone would say something about the K&N filter. Lol.

Thanks for the reply. I think I'll ended up replacing the filter with the oem. I'm a picky sob with a touch of ocd I reckon.

​​​​​​I thought about the thermostat aswell. Does seem cool to me. I'm trying to learn this truck since I've never been around diesels before so I wasn't sure about the average temp levels. Could that be a possible problem for the coolant coming out from the cap? I purchased a brand new cap, 16 psi, still have the problem.

 

Thats hydro carbon test is worthless on these trucks.....

Get yourself a gauge and hook it up to the coolant system so you can actually monitor the pressure under driving conditions instead of sitting in the driveway.

 

Will do, powerstroke. Appreciate the info guys. Hopefully I can get that done after work today.

 

The best way to confirm or rule out the head gaskets is to hook up a pressure testef that allows tou do see the gauge while you are driving. You want to carefully bleed off the coolant pressure at full operating temp before driving it. During the drive, find the steepest hill nearby and really lay into the throttle. A minor head gasket leak will only present itself under high boost. Building a few psi of pressure is fine, but if you're seeing the gauge bouncing at 16psi, time to open up your wallet.

if you still have the egr cooler installed, a leaking cooler can cause excessive cooling system pressure as well.

Nice tuner/gauges you have there. I had a sct x4 as well and loved it. If you end up studding the truck, you'll be opening the door for some nice custom tuning, so at least something good will come of it if your HG news isn't good.
If you do end up needing head gaskets, make sure the heads are machined, the block at least checked and machined if needed, and the surfaces PROPERLY prepped before it is put back together. O-ringing the heads adds even more insurance, but i wouldn't go that far, unless bigger injectors and turbo are in your future plans.

the thermostat is a very easy and cheap mini-project. If that is your running coolant temp, it's due. On a positive note, that is a very nice delta, especially with the low coolant temp.

 

Thanks for the great info brandon. I'm having trouble finding a low pressure gauge now. O'rieleys, Advanced, tractor supply, home depot, only thing I've found was 10 psi gauge and it was for a spray gun. The rest were 100+psi.

The previous owner spent about 3 or 4 grand on this truck studding the heads and egr delete. Pretty much this is the reason I choose to do a deal really. That and the camper was just a little too much for the F150. I tempted to pull the cab so I can check everything out.

I came across a thread about the "T" valve test thing that was very detailed and had pics. I can't seem to find it now. If anyome knows of a thread like that will you drop a reply with a quick link? Thanks

 

I didn't see earlier that the truck is already studded. If it has head gasket issues (again) it probably wasn't done right the first time. Even with studs with machined heads and block, improper surface prep or aftermarket head gaskets can cause a repeat failure.

Overfilling the degas bottle can also lead to puking. The cold min. line is the new cold max. line. My studded 6.0 would puke if i filled it past the cold min. I was afraid my head gaskets had failed. It passed the pressure test. 20k miles later, no change. As long as i didn't overfill it, it didn't puke.

 

Hopefully my outcome will be the same man. The last I checked there wasn't as much coolant around the filler opening as there has been. I'll still perfom the test as soon I can.

 

Grainger has some nice gauges, but you would have to wait on delivery. Harbor Freight has cheap ones. Not sure how accurate they would be, and they for sure won't last long.

 

Go to Home Depot, Tractor Supply, etc. Get a pressure gauge for a home well system.

 

This is what I was thinking, but since I'm cheap I would go check at your work or somewhere else that has a fire sprinkler system. NFPA code says gauges either have to be calibrated or replaced every 5 years. Most techs are lazy and leave the old ones at the sprinkler riser. Usually on top of the sprinkler box.

 

Update: My truck has not yet puked since the coolant level moved down to the min mark.

​​​​​​​Thank you for all of yalls info.

 

Glad to see you got it taken care of and thanks for the update

Resolutions and updates really help out the next guy when they're searching for solutions to their problems.

 

Tell your sprinks to get off their *** and haul out the old parts!