Coolant leak only when really cold outside?

[Josh2002cc]

Anyone know anything about a coolant leak that only occurs when it is really cold out like around 30 degrees or less? I have a coolant leak somewhere around the block to trans adapter that only happens when it gets really cold out. It does not leak when the motor is running or even 4 hours after you shut the truck down for the day. It also only leaks a small amount, maybe a 6" wet spot on the driveway...not a puddle or anything just a "wet spot". Did some searching but nothing really covers this perticular issue.

 

[TheBac]

Passenger side? Check that small rectangular cover on the adapter plate. You can see it behind the downpipe.

 

[whitetrash21]

Oil cooler feed?

 

[Josh2002cc]

Passenger side? Check that small rectangular cover on the adapter plate. You can see it behind the downpipe.

Sorry, it is on the drivers side.

Oil cooler feed?

No, this is not the case. It looks like it is above that. It is NOT the turbo coolant lines nor anything related to the valley running down the back.

 

[TheBac]

If DS, oil cooler could be weeping.

 

[whitetrash21]

Short of the rear plate or external head leak, not sure what else would bleed coolant on that side.

 

[Josh2002cc]

If DS, oil cooler could be weeping.

It is higher than that, I am thinking one of the ports on the back of the block that passes through the trans adapter plate.

Short of the rear plate or external head leak, not sure what else would bleed coolant on that side.

I don't know, it only happens when it is really cold out. For example, I parked the truck around 4pm today and it is now 10pm...no leak. Nothing. Sure as the sun will come up, there will be a wet spot there tomorrow morning.

 

[Mike_S]

Anyone know anything about a coolant leak that only occurs when it is really cold out like around 30 degrees or less? I have a coolant leak somewhere around the block to trans adapter that only happens when it gets really cold out. It does not leak when the motor is running or even 4 hours after you shut the truck down for the day. It also only leaks a small amount, maybe a 6" wet spot on the driveway...not a puddle or anything just a "wet spot". Did some searching but nothing really covers this perticular issue.

30 degrees is really cold? it regularly gets down to 0 or slightly below here where i live. I cant really see why something would be leaking only when the truck is cold like that, it could be related to system pressure though. Try relieving the system pressure before the engine is completely cooled off and see if the weep shows up sooner. It could be one of the o rings on the adapter plate is cracking or otherwise damaged and the expansion pressure is forcing the o ring to seal.

 

[Josh2002cc]

30 degrees is really cold? it regularly gets down to 0 or slightly below here where i live. I cant really see why something would be leaking only when the truck is cold like that, it could be related to system pressure though. Try relieving the system pressure before the engine is completely cooled off and see if the weep shows up sooner. It could be one of the o rings on the adapter plate is cracking or otherwise damaged and the expansion pressure is forcing the o ring to seal.

Okay, so to check this part about the pressure built up I went and drove the truck until it was good and warmed up. I parked it in the garage this time around and took the coolant overflow cap off ro relieve pressure. It has been over 3 hours and no leak as of yet. This is really driving me nuts.

FWIW, the temp last night was 0 and high today of 30. So while I said 30 was cold, it was actually much cooler than that over night. Sorry for the confusion.

 

[Josh2002cc]

Update: Parked the truck inside last night(non heated garage) and no leaks.

 

[JakeBrakeIH]

Mine did somethin similar. 1st thing in the morning I would see a wet some and it was coolant. Looked underneath, where the motor and trans met was damp. Well turns out the hose that runs into the heater core would drool down the downpipe and motor when it was cool out. Once it warmed up it didnt leak or anything. I just tightened the clamp and seems to be working for me.

 

[Josh2002cc]

Mine did somethin similar. 1st thing in the morning I would see a wet some and it was coolant. Looked underneath, where the motor and trans met was damp. Well turns out the hose that runs into the heater core would drool down the downpipe and motor when it was cool out. Once it warmed up it didnt leak or anything. I just tightened the clamp and seems to be working for me.

I really wish it was that simple.

 

[Josh2002cc]

Well, parked inside the garage last night and left the coolant cap ON, no leaks. So it obviously has to do with the cooler temps. The garage is not heated but is below the house so it is warmer than being outside in the wind and what not. I added about 4 oz of water to top it back off as well. I don't think I will be pulling the motor or trans to fix something that I am starting to consider a non issue, especially since winter is coming.

 

[Guatelupe]

Oil filter housing

I have had an issue similar to yours in that coolant is leaking just before the bell housing on the oil filter housing. I installed a lift pump and had to remove a plug and install a sensor. I believe this damaged the seals of the oil filter housing. I only get coolant at cold starts. For instance I forgot to plug in my block heater one morning which led to a -15f cold start had both oil and coolant leaking from this point!? Anyone know a good test for coolant tainted motor oil? No symptoms for that yet but I hate to change the oil without confirming that seal doesn’t introduce coolant into the oil pathway... this may be your leak point?