08 Job 1 odd Coolant leak

[canadian brickie]

The leak is somewhere on the the driver side of the engine behind and below the coolant reservoir. there is one hose about an inch in diameter like heater hose that comes across from the front of the engine and into the top of the firewall under and beside the high pressure fuel coolant reservoir. Here's the odd part the leak only happens when the truck is cold, when I'm running hot the frame rail and lower fuel lines are dry and no leak. Anyone have any ideas I lose about two quarts a month. I did check the high pressure fuel coolant reservoir and its right up and dry on the exterior the leak seems to be lower.
Thanks in advance for the help

[alexb]

Most likely the upper radiator hose leaking where it connects to the thermostat housing. There is an updated hose available that has an extra seal in the fitting. They usually only leak when cold, and normally without pressure applied. When they heat up, the o-rings expanding and the pressure in the system keep them from leaking.

[canadian brickie]

This morning I did a short drive to my shop and the fuel lines and frame rail were wet again not coming from anywhere higher than mid engine. I noticed that there is a small exhaust pipe running parallel and below the manifold driver side. There is a a short bent coolant line feeding this and the coolant seems to be leaking out of the joint on the pipe is this the EGR that everyone seems to have leaks with?

[canadian brickie]

I see that the EGR is on the top of the motor I don't know what the other component is that runs the side of the engine below the manifold. I'll try to post a picture tommorow

[MPD56]

HI Brickie: I think your looking at the horizontal EGR Cooler. Might be and hope that it is just leaking by the blue hose fitting? Shown in the cooling system manual on page 28 (bottom web link).

Powerstroke 6.4L Bible Page

http://www.backglass.org/duncan/ps64...ing_system.pdf


Cooling System Flow: EGR Coolers
• Cooled coolant flows out of the supply port of the front
cover where it is routed to the horizontal cooler at the left
rear side of the engine.
• The coolant then exits the horizontal cooler and is
immediately routed into the vertical cooler. The coolant
then exits the vertical cooler where it is routed to the return
port in the front cover.
• There is a small port at the top of the vertical cooler where
coolant is allowed to flow to the EGR valve, cool the valve,
then the coolant is routed to the degas bottle. This port is
also used as the deaeration port.
• Coolant flows through the EGR coolers and removes heat
from the exhaust before the exhaust arrives at the EGR
valve.

[canadian brickie]

Thats it thanks for the help, I can't tell exactly where the coolant is coming out but the horizontal cooler seems to be the culprit, getting worse goes into dealer Monday, should be covered by warranty.

[ford_doctor]

Originally Posted by canadian brickie

Thats it thanks for the help, I can't tell exactly where the coolant is coming out but the horizontal cooler seems to be the culprit, getting worse goes into dealer Monday, should be covered by warranty.

I have seen loose hose clamps at the coolers a couple of times... but don't be surprised to hear that the leak is migrating from somewhere else. Regardless, DO have this repaired quickly as low coolant levels in these engines causes bigger problems.

[canadian brickie]

Thanks everyone for the help this forum is a great source of knowledge!! keeping an eye on the level the good thing is it only leaks when its cold when it heats up no leak I loose about an inch every two days if I run it. Dealer appointment Monday first thing.

[canadian brickie]

They found it! After three days in the shop they located the leak in the hose that supplies the horizontal egr cooler. They also discovered that both thermostats were not working and the degas cap was faulty, all covered under warranty, it did take four days once the parts came in.