Truck information:
EGR Delete
APR Head studs / OEM headgaskets
New oil cooiler & blue spring + new screen
Power max turbo
^------ 2.5 years ago----^

New thermostat
175 CC injectors

I noticed the other day that my coolant tank took almost another gallon after I just filled it about 8 months ago.. I had my injectors recently done so I'm not sure if that had something to do with missing coolant and the technicians that did it.. I found this out while I'm trying to diagnose a bad heater core.

I have no symptoms of head gaskets (truck was studded / egr deleted three years back). My only suspicion is due to the loss of coolant.

I attempted to due a block test with green dye that should turn yellow with exhaust gases present.. I got the opposite results. My liquid turned darker. Picture is attached. Should the fluid get darker? Would it be due to the exposed heat of the coolant? Did this test go wrong?

Attached picture:
Left bottle is exhaust gases after 20 seconds
Middle bottle is control / unexposed
Right bottle is after four minutes above the degas bottle.

I also attempted to put a T right before the degas bottles coolant return line and checked the pressure with a gauge. Running PSI with the truck warmed up with no load was around 5. It wouldn't run any higher unless I let the truck loose.

When I would pull a WOT from second to fourth gear the PSI would jump with engine load two to three seconds lagged. Generally, the PSI jumped anywhere from 4-10 PSI per WOT run, the most I could get was a 5-12 PSI jump in about 3-4 seconds. Not once did the PSI peak over 14.

While the PSI peak is OK, should I be concerned that my PSI jumps with the load when I go WOT

 

There are a few things that may have happened. Are you useing the diesel test fluid.? There is one for diesel and one for gasoline, mixing them up can cause strange results. When drawing in your gas sample you are getting gas only and none of the antifreeze, this also can contaminate the sample. Depending on the brand and age of the test fluid will sometimes make a difference. Other than not actually having any exhaust gas in the sample to change color I am not shure why it would get darker.

 

I used NAPA's brand block test liquid made for Diesel / Natural gas / other non-standard gasoline fuel mixtures. I suppose anti-freeze getting in there would be the only explanation but I'm just baffled how it did so as I held the tester far high enough.. The temperature was about 20 degrees outside and the truck was still hot. I had a bit of steam coming out of the degas bottle from the ambient air / degas bottle temperatur difference. Maybe from there?

My next step is to do a head gasket pressure test through the degas bottle. I can't find a regular air pressure gauge that goes under 300 PSI anywhere around me so I had to order a pressure gauge.

I ended up going to Advanced Auto and borrowed a coolant pressure tester. I was able to hook it up to the degas bottle. The truck was still hot when I did the test with 25 degree weather outside. I pumped the pressure a bit higher than the recommended to 20 PSI and let it sit. It lost 1 PSI in 15 minutes. It held rather hard and didn't appear to have a leak.. My assumption for the 1 PSI loss may be due to the antifreeze coolant losing pressure as the previous heat expansion dissipated off due to the freezing temperatures. Can't get a definitive answer from this test either

 

I did a pressure test under load, I couldn't get the psi above 13 under heavy load. However, the needle would bounce around with a delayed response with engine load and wouldn't do a 'casual rise' per se. The most severe one i was able to get the pressure from 5psi to 12ish in about 3 to 4 seconds. Ideas thoughts opinions anyone?

 

Do you still have a egr cooler?

 

Egr cooler was removed. Truck was restudded with arp bolts and oem gaskets 2.5yrs ago..

 

I will give control numbers. Stock engine. My coolant pressure with the degas filled 1/2" below min line on bottle, reaches 8 psi at 190 ECT, reads 0 until 150ish. My truck has only ever seen ECT of 217 because it was working and revving hard to pull someone out of a snowbank, PSI hit 12. You're coolant should rise with temp more than your pedal, mine does flutter with the pedal a bit but it could just be the change of flow

 

How much does your gauge flutter with the pedal?

I have a decently plugged heater core. I was thinking it was possible that there was pressure build up / release when the coolant finally was getting shoved through it. That was my latest theory in this, but since the coolant system is a closed system, I'm not sure if this would be able to increase pressure in the system.

 

Sounds like to me that you need a cooling flush,you haven't mention if you are running ELC. If your delta's are good, I wouldn't flush with chemicals, just water and use the procedure in the tech folder up top.

 

maybe .5 of a psi, no where near what you are seeing of 7 psi swings. it should mainly travel with temperature

 

Ford Gold. I'll check the deltas when I leave work. I'm not sure their range.


I noticed yesterday my truck takes awhile for the coolant to warm up. In normal weather it's fine(ish).. we just got hit this week by a spell of 20 degree weather and I noticed how long this now takes. I'll go on break about a half hour before my shift is over and let it idle for 10 minutes. The truck sits turned off for another 20. After about a 10 minute drive, the coolant temp gauge will finally move. Transmission temperature gauge comes upto speed just fine. **** is going bad everywhere.. Any chance a bad radiator could cause the symptoms I'm having?