Slow loss of cooling fluid

flash7210 · **Posted:** Thu Jun 01, 2017 9:45 am

The best way I have found to test for a head gasket leak, cracked head, or ERG cooler leak is...

1. Get a cooling system pressure tester.
Pump it up to 16 psi, walk away, come back 30 min later.
Check for pressure drop on the pressure gauge. Check every possible hose connection for drips and wetness. Also check where the thermostat housing bolts to the head.
If drips/wetness is found, replace clamps and/or leaking hoses.

2. Head gasket.
Unplug all four injectors (or pull the ASD fuse) and remove all four glow plugs.
Crank the engine.
If water comes shooting out the glow plug holes, you have a head gasket leak or a cracked head.

3. EGR cooler.
If your EGR system is still attached along with all coolant hoses going into it, loosen the two bolts that hold the lower EGR tube to the EGR valve. This is the tube that attaches to intake elbow.
Gently pull back the part you just loosened and feel around the bottom of the EGR valve.
Any drips or wetness indicate a EGR cooler leak.
Note: If you already have the Sasquatch stage 1 intake elbow, this lower EGR port should be blocked with a plate. Loosen or remove the plate and inspect.
If your EGR valve still has coolant lines attached to it, regardless of whether the valve is functioning or not, it can still leak coolant internally.

4. Cracked head.
If step 2 confirmed that you have water getting into the cylinders, you will have to start preparing to pull the cylinder head.
As you start disassembling the motor, do your best to keep all cooling system parts and hoses connected.
You will have to remove the timing belt, inner timing cover, injectors, and valve cover.
Also remove the turbo and exhaust manifold.
Next, reconnect any coolant lines you may have removed and top off the cooling system with water.
Pressure test the cooling system to 16 psi as you did before and walk away for 10-15 min.
Come back and inspect the exhaust ports in the head.
If water is dripping out of the exhaust ports or has pooled in the ports you have a cracked head.
You can also try inspecting intake ports by peeking down into the holes on top of the head.

Note: the cracked head test may not work 100% of the time. If you are removing the head to replace the head gasket its best to send the head off to a machine shop to have it pressure tested for cracks.

WWDiesel · **Posted:** Thu Jun 01, 2017 10:23 am

I do not believe the exhaust could overcome and force a bubble into a closed cooling system via the EGR cooler!
Most likely the bubble you observed came from a leaking head gasket or worse yet a cracked head; hopefully not the latter!

But as you stated, when you take it apart, the following upgrades should be done if time and monies allow:

TKB4 · **Posted:** Thu Jun 01, 2017 12:09 pm

Greatly appreciate the quick replies. I plan to go ahead and remove the egr system this weekend. I have spare radiator cap on salvage jeep may just drill out and put air fitting in with gauge and air valve to quick attachin it and pump up with compressor. Unless the cap pressure is less than 16 lbs. Anyway worth a try for 20 minutes work and its here and free.

Btw use similar method on hydraulic reservoirs and if tractor runs out fuel to prime quick just cut piece inner tube with valve and tie or clamp around fuel neck. Pump some air pressure in and crank, works great! Of course you have to refuel etc first.

I think I did notice some white smoke at cold start up couple times recently that haven't noticed before that would be consistent with small exhaust coolant leak.. Hopefully its head gasket leak just to exhaust . If it is guess it couldn't really hurt engine to run it . If cracked head its already a major problem but have salvage jeep that may have good head. If coolant to cylinder proven by glow plug removal I am sure I should stop driving it till fixed to avoid possibility of larger leak and hydrolock etc. For now, will not drive until I know.

I will let you know whatever I find out, and progress after the weekend.

Belizeman · **Joined:** Tue May 23, 2017 5:47 pm **Posts:** 26

My truck is in Belize, the 30 second test was down by a friend and showed no leak/pressure in the cooling system. we are watching the fluid level but IF it is a head gasket or an EGR leak, is it safe to drive the truck???

TKB4 · **Posted:** Thu Jun 08, 2017 7:50 pm

after looking at some you tube videos etc another way to test for head gasket leak causing coolant loss is checking the gas content in the coolant reservoir for carbon dioxide monoxide if present in any significant concentration above air levels it has to be from the combustion process leaking it into the coolant.

My question is:

With a very small leak would it be worth changing bolts out for ARP Studs without pulling head to see if that would seal it?

I assume one could do pressure test to see if it worked or at least an idea that it may have worked before replacing intake and if it didn't go ahead and remove head inspect etc.

GordnadoCRD · **Posted:** Fri Jun 09, 2017 4:10 am

IMO the short answer would be 'yes'.

IF it hasn't been leaking for an extended period of time, resulting in localized mineral deposits between the block and head
IF you aren't running a 'Hot' or 'Full torque' tune, because of the higher cylinder pressures. (this is not an absolute. It may very well work even if you have +P tuning)

1) the likelihood of successfully re-sealing is significant
2) it can be added to the next timing belt change with only a couple hours time or less.
3) R&R the head involves a very large addition of labor, and many potential additional questions/issues.
4) IF it doesn't work, the amount of labor "wasted" is relatively small.

TKB4 · **Posted:** Sat Jun 10, 2017 3:05 pm

Well I have about got glow plugs out and it just hit me (slow I know) doubt turning crank by hand would spew much coolant out so I guess would have to ensure clearance and hook battery back up to do this to check for head gasket leak it failed the coolant pressure test. Removing egr and cooler to test ( lol) them now For offload use after repair. I plan to pull ASD confirm it won't Start then pull glow plugs and turn engine over with starter.

So do you need to use starter for test or would just turning crank by hand be enough ?

Slow loss of cooling fluid

Who is online