Home
In the past 3 months i've had to add at least a gallon of coolant, twice to my trucks coolant tank. There are no leaks that I can see and my engine oil is clean. I've noticed a few times after parking my truck and walking by it sometimes I can smell coolant but like I said, I could not find any leaks.

I was told by a friend that it could be going into the cylinders, my question is, how can I tell if this is what's happening?
If you have a transmission cooler with lines that run through the radiator could be a leak there. If transmission fluid looks milky (whitish) that could very well be the indications of this problem. Ask me how I know. Or it could be as simple as overheating problem being boiled out of top of radiator. I would think if you can smell it that it is boiling out somewhere. Maybe stuck thermostat, any over heating problems? Tom.
A little more info. I did a coolant flush and fill this past summer and it has a new thermostat and cap.

Both hoses were hard when I checked them yesterday which indicates to me the system is pressurizing. I knew I was low on coolant while driving home yesterday because the temp gauge would rise just a little bit past half. It would stay there when I was at idle and blow cold air from the vents but as soon as I started driving it would drop back down and the air would warm up.

I'll check my tranny fluid tonight.
I was having a similar problem in my 01. just couldn't see whenre the coolant was going, but it would be low every month or so.
finally saw that the gasket between the block and timing cover was leaking down on the side. Just enough so that when the engine warmed up and the cooling system was pressurized it would mist out, not enough to see a leak, but it was leaving the system.
Check to see if you're loosing coolant out of the water pump. When the bearing and seal start to go on the water pump, there is a seep hole and you'll loose coolant out of the seep hole.
It is possible, and likely, to have an intake manifold gasket leak and see no evidence of an external leak. The coolant gets sucked into the combustion chambers and get's burned up.
Originally Posted by 458 Lott
Check to see if you're loosing coolant out of the water pump. When the bearing and seal start to go on the water pump, there is a seep hole and you'll loose coolant out of the seep hole.


This would be my bet. Although Paul and I are both probably a little oversensitive to that particular issue as we've both got 5.9 Cummins.
Originally Posted by cwh2
Originally Posted by 458 Lott
Check to see if you're loosing coolant out of the water pump. When the bearing and seal start to go on the water pump, there is a seep hole and you'll loose coolant out of the seep hole.


This would be my bet. Although Paul and I are both probably a little oversensitive to that particular issue as we've both got 5.9 Cummins.


Same thing happened on my 03 GMC. Was losing coolant, couldn't ever see any drips. After my mechanic pulled enough shrouds to really look into the engine bay, you could see residue around the water pump where it was leaking and evaporating.
You should be able to see on the spark plugs if it's ending up in the cylinder.
Wife's '99 with the 360 in it was leaking around the base of the thermostat housing, NAPA makes an excellent replacement part - the factory was cheap stamped steel.
Originally Posted by cwh2
Originally Posted by 458 Lott
Check to see if you're loosing coolant out of the water pump. When the bearing and seal start to go on the water pump, there is a seep hole and you'll loose coolant out of the seep hole.


This would be my bet. Although Paul and I are both probably a little oversensitive to that particular issue as we've both got 5.9 Cummins.


Why they put a $50 water pump on a $10k engine just baffles me.

Swapping it out on my own dime was less hastle then having to deal with morons at the dealership to get it fixed under warranty. Seems the new ones been holding up ok.
I looked the engine bay over yesterday after getting back from town. Crawled under the truck and noticed someting running underneath the lower coolant hose and the frame underneath it was wet. I didn't smell coolant but I don't know what else it could be. If it was being burnt up in the comb chamber would I smell it in the exhaust?
You want to borrow a pressure tester? Warm up the engine, put the right amount of pressure into the coolant system and it will show a leak. Ill let you use mine if you want. I drive by ER every day. I also have a compression gauge set you want to see if a head gasket is bad. Edited to say if its an external leak. Very important part.
Water / coolant that is sucked into the chamber will vaporize and you won't see it.
Start it and don't let it heat up and put your hand at the exhaust and see if you can feel alot of moisture
Excessive coolant burning in the CC will show as white exhaust..

You can also check under the oil fill cap for chocolaty, thick sludge indicating coolant leaking into the crankcase.

No smell in the interior? Then heater core probably OK.

IIRC you can add a dye into the radiator and check with a black light to see if it is leaking around teh engine..

Another trick is run a mirror on a stick around the hoses and heads and water jacket areas to see if it fogs up after shutdown.

Dusting a clean engine with baby powder also will show a leak..

Just a few ideas I can remember from my old rodding days.
Well a few weeks back it was low again so I added about a 1/2 gallon of water or so to it and ever since then it has been fine. I topped it off with some recommended G05 coolant mixed 50/50 with water so we shall see what happens.
© 24hourcampfire