Coolant leak

Greenie

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After weeks of zero leaks on the garage floor (fixed ATF, diesel, and motor oil leaks) a large dog sized *** puddle presented itself this morning. It seems to be coming from the the passenger side toward the rear of the motor but I can't see where it's coming from. The truck (1993 280K miles) is on its 2nd radiator and original heater core. There's no leaks or smells in the passenger compartment. Can a heater core leak and not stink or fog up in interior of the cab?
 

Rdnck84_03

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That is completely dependent on the atmospheric conditions. It is definitely possible. I believe the obs has a drain on the bottom of the heater box to keep coolant out of the floor. I know the bullnose usually leaks in the floor.

James
 

IDIBRONCO

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Check out the block heater. They can start to leak. Actually it's either the o ring seal around the outside or, sometimes, the seal on the center bolt can leak. The one in my engine is leaking around the center bolt.
 

DrCharles

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The IDI can leak from places you didn't know existed, and frequently does ;) I had a leak like that, but smaller. Turned out to be coming from the thermostat housing, sneaking down along the cylinder head and dripping off the bellhousing.

Keep in mind that the fan can push coolant a long way to the rear... also the windblast coming through the engine compartment may relocate a drip far from the source...
 

Greenie

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I got access to the heater core - everything looks pristine inside there - the bottom of the heater core box was dry. The passenger side of the engine compartment including the passenger side front wheel well is wet. The water pump bottom appeared dry and my worthless bore scope was on no use. When I removed the radiator cap I heard a slight vacuum so I left the cap off and went back underneath - it's dripping now - right from the crank pulley area so I'm reasonably sure the water pump is leaking. Napa should have one early tomorrow morning.
 

RSchanz

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I got access to the heater core - everything looks pristine inside there - the bottom of the heater core box was dry. The passenger side of the engine compartment including the passenger side front wheel well is wet. The water pump bottom appeared dry and my worthless bore scope was on no use. When I removed the radiator cap I heard a slight vacuum so I left the cap off and went back underneath - it's dripping now - right from the crank pulley area so I'm reasonably sure the water pump is leaking. Napa should have one early tomorrow morning.
What was the relevancy of the slight vacuum sound heard when removing the cap? Can you elaborate on this?
 

Greenie

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What was the relevancy of the slight vacuum sound heard when removing the cap? Can you elaborate on this?
When the cold engine sat finding an active coolant leak was aided by removing the radiator cap which allowed the coolant to drip from the water pump area. Previously the airflow carried the coolant along the passenger side of the engine and it was hard to determine exactly where the leak was.... The vacuum held by the radiator cap on a cold engine didn't allow the leak to drip.
 

ihc1470

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Put a radiator pressure tester on it and pump it up to 15 pounds and you should have a pretty good idea where it is leaking from. Every tool box should have one.
 

Lumberjackchuck

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Mine did this it was a loose clamp on the Thermostat housing.

Same, and somehow it ended up in the valley pan and drained out the back and down the starter.

My mind was blown when I looked in the valley pan and saw a red liquid in there. I was like ‘dang I got off road diesel in here?” thinking I had a return line leaking into that spot.

But nope it was coolant. Tasted it too for extra confirmation.
 
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