Anti freeze smell when truck is running.. head gasket?

[Jeff213]

I cant find any oil in the coolant, and the oil was just dirty as hell, not milky. I just changed out the oil and drove it for a while and the oil is still super clean, but I smell anti freeze when it is running.

I am going to pull the plugs and check for odd fouling, have you seen a head gasket go out without actually showing visible signs of a head gasket failure?

Are there any other things that could cause this anti freeze smell? this is on my 98 5.0 mounty that I am going to be fixing up and turning into the offroad beast that my 98 5.0 eddie bauer used to be.

This anti freeze smell is more outside the truck than inside the truck also, a neighbor noticed it and said he thought i had blown a head gasket when I was driving down the street past him.

 

[Jeff213]

Just tested for head gasket leak with the napa auto parts fluid test on the radiator cap, didnt show any contamination of exhaust gasses in the radiator. It must be a coolant leak somewhere dripping on the exhaust manifolds or the block.

 

[Mbrooks420]

Check below the water pump, and the heater control valve. This can leak on the manifold and cause quite a smell, but show no puddle.

 

[fast_dave]

Check below the water pump, and the heater control valve

Mbrooks420 is spot on - I've experienced BOTH.

WATER PUMP

A few years back I got a bad, factory new, BOSCH lifetime water pump that had a bad shaft seal.

The shaft seal was only slightly damaged, and only leaked after the Ex was driven, and the cooling system was under high pressure.

So what was essentially occurring was the coolant was leaking out BUT vaporizing due to the fact it was BOTH hot & under high pressure, so it left no clearly visible trace through the "weep hole"

It was a head scratcher for years because the water pump pump bearings were fine, there wasn't any visible leak, and yet I could always catch a whiff of anti-freeze when I got out of my Ex after driving it.

I was having to fill the coolant overflow tank every 4 weeks or so to hit a reference mark, so I knew it was a pinhole leak. Man - I searched everywhere to find it (or so I thought)

Finally found out what was occurring when I replaced my Timing Cover Gasket this 2nd time, and had to pull off the Water Pump to replace the timing cover.

Upon close examination, I could see a film of dried anti-freeze within the weep hole.

Replaced the water pump - along with the Timing Cover Gasket - and my coolant level in the overflow take has held steady.



Heater Valve

Factory FORD heater valve went bad, and was leaking under pressure from where the stainless steel pin for the flap valve enters the body of the valve.

Coolant was coming out under high pressure, vaporizing, and leaving a white film on the passenger side exhaust manifold.

Could smell anti-freeze in the cabin when the vent was on because the fresh air pick up is right below the passenger side of the windshield.

Replaced the valve with an aftermarket one, and a few years later that one leaked too - in the same place - where the stainless steel pin for the flap valve enters the body of the valve.

Finally dug deep in the wallet and bought a FORD part - and all has been well (knock on wood).

 

[Jeff213]

Thanks guys I will checke these out.

 

[Turdle]

Another place to check is the air baffle under the radiator. If the plastic tanks leak the drips usually go there-

Are you loosing coolant?

The reservoir tube can become clogged inside the reservoir. This will allow air to burp out, which will move the clog, but when the rad tries to suck coolant back in, the clog will move to the nipple and block the flow. You might check this also.

 

[Jeff213]

I got the loan a tool from autozone and pressurized the coolant system cold and it looks like there is a slow leak from the water pump. It is dripping on the block so whe its running it all evaporates, but cold it was dripping down to the ground. Thanks guys, looms like i will be doing the water pump.