My 99 CTD is using coolant. Nothing in the oil, or leaking, although I often smell anti-freeze when get out of it. Why is all this sludge on my radiator cap?

 

looks like oil you might have a cracked f to f cooler or blown head gasket is the truck a automatic? also fill in your signiture so we know what your truck is equip. with and any mods. also look on the pass. side of the block for a crack........ you might have a 53 block and its cracked the stuff in the rad. could be block seal?

 

Rebal, What is the f to f cooler? Truck does have the 53 block but like I said, even when pressurized to 15 lbs. no leaks any where, no coolant in trans fluid or engine oil. I'm changing the radiator cap asap, it's a little flakey when tested. Could it just be the cap is venting and trapping all the impurities in the system where it is venting to the reservoir always, thus the odor of coolant when I exit the truck? Looking into the radiator, I can see no sludge.

 

Coolant reservoir could be steaming some off, or leaking at hose connection, head gasket or cracked head can pull minute amount of coolant into cylinder and burn it off.

Also, check passenger floor for wetness, could be a failing heater core...

Just some thoughts.

 

Also check the weep hole on the water pump for the source of the smell, the sludge is oil possibly from a blown head gasket. Combustion pressure is pressurizing the cooling system and blowing the radcap and possibly the water pump seal.

 

Fluid to fluid ...heat exchanger oil pressure is higher the the 15lbs in the rad so its ether head/or gasket or heat exchanger pushing oil in . you should test the rad, for pressure with the engine running and under a load and see how fast the psi gos up but just looking at it I would bet its a head gasket .

 

I have pressure tested the cooling system, no leakage. I've left the pressure tester on the radiator with engine running, no pressure seems to be leaking into cooling sys. Not tried this test under load yet, will install new cap tonight and see how it behaves then. Thanks for all replies.

 

you can get a kit that goes on the rad where the cap goes and will turn colour when combustion gas is present in cooling system

 

What would the going rate be for a head gasket replacement? Any upgrades recomended? Thanks for all replies.

 

Depending on what mods you have and how you use your truck you could go all out and do head studs, fire ring it etc, and could spend a small fortune.

If its stock and you do it yourself you will save a lot of money. Shops are around $85-$100/hr around here.

Fill out a sig so we know what all you have modfied on your truck and what you use it for.

 

Mainly used for towing my 28' race trailer, 10,000 lbs.