Author Topic: Mystery Coolant Leak  (Read 236 times)

Offline FarleyJ

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Mystery Coolant Leak
« on: August 02, 2020, 03:05:16 PM »
I am at the end and donít know where to look for this mystery coolant leak. I have a drip every 30 seconds off the starter while it is running. It continues to drip after itís turned off but the truck never overheats. I parked it a week ago and it is still dripping even while itís been sitting in the garage not running.

I have verified the head gaskets, headbolts, intake gaskets, hoses and fittings, and freeze plugs are good. I put a pressure tester on it and absolutely not one drip came out.

Any thoughts?


Online bd

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Re: Mystery Coolant Leak
« Reply #1 on: August 02, 2020, 03:51:46 PM »
Are you using brightly colored antifreeze or plain water for coolant?  Make sure that the radiator is full.  Install the pressure tester on the radiator and pump up to ~20 PSI with the engine cold.  Check the water pump-to-block gaskets.  Difficult to diagnose fluid leaks occasionally require dye, a UV light and filter goggles to locate.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline FarleyJ

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Re: Mystery Coolant Leak
« Reply #2 on: August 02, 2020, 04:40:18 PM »
I forgot to add I did add dye last week and forgot. I ran out and shine the black light and there is coolant around the starter. It goes from the lip of the oil pan front to back on the passenger side. Most of the saturation is around the starter bell area. I also shine it all around the water pump and back of the engine and they are clean. The part that is confusing me is the leaking while it is been sitting.

Offline FarleyJ

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Re: Mystery Coolant Leak
« Reply #3 on: August 02, 2020, 05:02:56 PM »
Ok so I pumped it up to 20 ish PSI and got under it and it looked and it was running down the lip of the pan on the starter. It seems to be coming from the block drain fitting. I guess when it would go back and hit the flexplate it was slinging it all over the place. Sorry if I wasted anyoneís time....itís been a long weekend.

Online bd

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Re: Mystery Coolant Leak
« Reply #4 on: August 02, 2020, 06:21:21 PM »
So hose everything off with a garden hose, blow or wipe it somewhat dry and repeat the process to validate your diagnosis.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline FarleyJ

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Re: Mystery Coolant Leak
« Reply #5 on: August 02, 2020, 08:30:01 PM »
Will do thanks bud.