Coolant leak - please help diagnose

[Gudor]

Hoping to get some advice, this is my first post on therangerstation. My son (his first car) and I just picked up an '87 Ranger with 2.9L automatic (2WD ext. cab). The odometer says 21,000 and I think its 121,000 because of how clean it is. We drove it home about 70 miles and it lost maybe a quart of coolant along the way. I did some searching on the site - tightened hose clamps, checked freeze plugs, etc. There doesn't appear to be any cross-contamination with oil/coolant. I hooked up coolant pressure tester and at about 15 psi it leaks (doesn't appear to leak w/o pressure). I couldn't find where the coolant was exiting the system, but it appears to be on the drivers side. The first picture is of the front drivers side. Just above the oil pan it is collecting some - it never created enough to drip there.

The second picture is where it is really concentrated. The coolant is coming from just above the starter dripping down the flexplate/bellhousing and dripping to the ground from the three Xs (bottom starter bolt to the middle of the inspection plate). Under pressure it drips, it is not a steady stream. I pumped the pressure to about 20 PSI and after about 15 minutes it was about 18 PSI.

I was able to see the back freeze plugs and I am nearly positive it is not them. One freeze plug (front drivers side) needs to be replaced - it lets a tiny bit out (hoping that is the cause of the buildup on the front drivers side), but it is definitely not the cause of the coolant near the starter.

The truck is actually super clean and was obviously taken care of. My son hopes to have it for many years, so part of me just want to replace all the gaskets that touch coolant (I have heard the head gaskets of the 2.9 are problematic). I am handy and have done some work on cars, but pulling the engine seems a little daunting. Is pulling the engine only necessary if the problem is the back freeze plugs? Could all the coolant gaskets be replaced w/o pulling engine? My preference would be to fix the problem without doing extra and tackle the entire system on our terms as maintenance.

Any advice would be appreciated - including good tutorials/videos you are aware of. Also, things I 'should probably do' since I'll be there anyhow (like timing belt/chain, water pump, etc.) even if it isn't giving me problems.

Thank you.

 

[Uncle Gump]

It could be a head gasket.

It could be an intake manifold gasket leak too.

Removing the starter will give you a better view.

Using a mirror will also let you see the rear of the engine better from up top.

 

[RobbieD]

Freeze plugs are definitely suspect on a motor that old. Over time, they corrode on the inside surface, and you end up with pin holes.

Do get an inspection mirror and a flashlight, and usually you'll see the stains from the coolant, and not necessarily the holes themselves.


Welcome to TRS.

 

[SenorNoob]

No way to know without pinpointing it.

My front core plug on the driver's side weeps. Right through the middle. It's easy to see. Loses a teaspoon or so every time I drive it. Really need to replace that before it gets worse suddenly.

 

[alwaysFlOoReD]

I had a 4.0 that had pinholes on the back of the heads. Likely if the coolant level has been low for extended periods. I've used rubber freeze plugs replacements with success,... and one disaster. The disaster was my own fault for not getting the plug in square to the hole. I saw it but figured it would hold... oops!
I've never tried to use them on the back of the head while the engine is in the truck, but I would sure give it a try before pulling the engine.