79 TA Coolant Leak At Inspection Plate

Jolo

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I need to look into a very small drip of antifreeze under the bell housing inspection plate I found after running and driving for a while After the car had been off the road for a year. I’m concerned because I just replaced the clutch. I suspect I may have tugged the heater hose when I lifted the engine to drop the oil pan and may have gotten a drip between the bell housing to block seam. I just don’t yet see a leak up there or anywhere other than at the bottom of the inspection plate. I inspected the freeze plugs and the rear of the heads when I replaced the flywheel. I will move the starter and drop the inspection plate and pop a camera up there if necessary. I will also check the coolant for evidence of exhaust and a blown head gasket but I see no evidence of coolant in the oil or at the exhaust tips. Anyone have a similar experience?
 
You can also try a lighted mechanic extension mirror to look at the heads again and if worm clamps tighten the heater hoses.
 
Everything appears dry except the bottom of the inspection plate and the bump out on the passenger side of the bell housing next to the oil filter. Coolant leaked down to there and onto the inspection plate. Wherever it’s coming from is leaking only when the coolant is flowing. I think it is up top in the heater core at the hose connections or the heater hoses are loose or cracked. I will put the starter back in and run it to see if I can isolate the leak. Well it ran and drove great for a few minutes, and now it’s back on the lift. So it is with old and brittle cars.
 
It could be the heater core, or one of the heater hoses or the hose connection on the back of the passenger side cylinder head. More remote possibilities are the freeze plug on the back of the passenger side head, or a head gasket leaking.

I would clean everything up, and tr to pressurise the cooling system and check for leaks. Usually if it is a leaky heater core you will get steam & coolant out of the defroster vents and on the inner windshield. If it doesn't leak all over the passenger side foot well.

Good Luck with the issue. And please let us know what you find!
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Happy 4th. Here is an update. I cleaned up the leak and re-installed the inpection plate and ran the car at idle for fifteen minutes. The car idled just fine at around 775/800. The temp gauge climbed to center and stayed planted there. I assume the gauge is not accurate at 220, and I assume the car is runnimg at 180/190, but the gauge did not climb any further than dead center and on a mid nineties day I was happy it did not overheat while idling. I will pop out the thermostat eventually to see what is in there. No further leaking at the inspection plate. It could be that when I lifted the engine I forced a hose leak at the connections to the heater core and the fluid landed on the inspection plate and slowly made its way through the weep hole, but no new fluid after this idle test. But after that test I had one big concern. The car was in the garage and I smelled antifreeze while it was idling. So, I moved onto the next test.

This morning I just ran a block leak test. I started the car with the radiator cap off and I:
1. noted no coolant movement or bubbling in the radiator,
2. no condensation on the radiator cap. I had also no condensation or water/coolant on the oil filler cap, on the spark plugs or in the spark plug holes. Also no evidence of coolant in the oil when I drained it, or steam at the exhaust tips, and no smoke from the engine compartment.
3. added the block tester tube after engine warmed. I wanted to be sure the thermostat was opening and coolant was flowing, so I ran the block leak test with the heater off and again with it on.
4. with the temp gauge at 1/4 reading, I pulled air into the tube by repeatedly for several minutes, pumping the tester bulb. The fluid remained the same color blue with no deviation at all. So that test thankfully checked out indicating no evidence of exhaust fumes mixing in with the coolant. The coolant is extremely clean as well.

So, I think it is safe to conclude I have no internal coolant leak either via head gaskets, block or head cracks, or corroded freeze plugs. And no external leak onto the engine at the heads.

With no internal leaks, I think I can safely drive the car and focus my attention on the source of the external leak near or from the heater core. Thankfully, no coolant on the passenger side floor.

Anything I have missed? Any ideas why I smell antifreeze when the car is running? Maybe the smell is from the external leak I cannot find.

I will drive the car and keep an eye on it for any further leaks. If I thought I have an internal leak, I would run a compression test, but I may do that as well for good measure.

Thanks as always and have a great holiday. Cheers to the USA!!!

Kind regards,
Joe
 
How about renting a pressure tester for the cooling system including radiator cap?
 
Good idea. I was looking to buy a cheap one, but the cheapest seems to be more than I want to spend. My local Auto Zone and Advance in the Hilton Head area are pretty poor on tool rentals. Not too many gear heads here. Any other options for rentals? That said, since I don't suspect an internal leak, I will just keep an eye out for any additional external leaking.
 
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Good idea. I was looking to buy a cheap one, but the cheapest seems to be more than I want to spend. My local Auto Zone and Advance in the Hilton Head area are pretty poor on tool rentals. Not too many gear heads here. Any other options for rentals?
Sorry, totally unfamiliar with your area. A Google search also showed NAPA as a possibility.
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