I have a leak from a sensor or plug I cannot identify. It is passenger side on the block in between the starter and exhaust manifold. There is an electrical plug that goes to it and a bolt with a flat head slot in it. Started getting on the hot side yesterday when driving back from work and I pulled over, let her cool down, then had to add 2 gallons to get her right. I've been searching the forum, but can only find threads on the temp sensor on the driver side head. I will add a photo shortly, phone has to charge.

 

Please disregard, this is my first diesel, and I wasn't able to figure out that wires only run so many places on an IDI. It's the block heater that is leaking... sorry for a useless post.

 

Did you get it fixed?

 

mehhh. if you figured it out, it is not a useless post.

 

I agree, it is not a useless post, this is how we learn. Iam 80 and still learning.
Get a big pan to drain the coolant in. There is a brass plug, I think it is forward
of of the Block Heater. Takes a 9/16" to remove. It will drain the Block on that side.
There is another one on the Drivers side also.
When you remove the BH you will then not have have a big rush of coolant rushing out.

I use one of these HD Mixing pans to drain fluids in.
https://www.homedepot.com/p/Medium-M...A-41/318924439

The rubber "O" Ring has probably deteriorated on the BH.


Charlie

 

Had to do some running around today and stopped by a pick n pull looking for new seats and what did I find? and 86 idi. Snagged the radiator because it looked like it's in good shape and had a cooler in front of it and for 100$ it seemed like a good investment. Picked up a new block heater from NAPA today as well. Fixing tomorrow. I was also wondering if its possible to delete the block heater with a freeze plug? Just a thought since I live in Sacramento and cold is not an issue here. @Charmalu I'm sure you are right about the Oring. I've never seen a press fit Oring that doesn't fail prematurely. Having worked for Parker's Oring engineering department it drives me nuts to see these squeeze fit Orings all over engines.

 

Make sure you remember the element orientation, iirc its element at 11 o’clock. Don’t want the element touching the block

 

I bought my 86 in Sacramento in 2014, saw it on CL, bought it for $1800 with 192K miles.
3 years later the Oil Cooler puked oil into the cooling system. Fixed the Cooler and then the
job of cleaning out the cooling system of the black goo. I was removing the Brass Block plug
when I noticed around the BH it was green and grungy looking. It may have been the original.
I did replace it with a new one.
I live just over the hill from you, and it can get cold here.
The Freeze Plugs these engine use are a different style and you need a special tool to set them.
I``ll see if I can find a thread on them.
Here are a few threads I came across.
https://www.oilburners.net/threads/h...e-plugs.22387/

https://www.oilburners.net/threads/w...on-tool.77683/

https://www.oilburners.net/threads/f...ug-tool.93375/

https://www.oilburners.net/threads/f...ug-tool.90845/

https://www.thedieselstop.com/thread.../#post-4293153



Charlie

 

How bad is this? It looks like half the wing nut has decided to release itself into the engine block? Any change something that big could block a cooling jacket or make it's way to the water pump? Should I go on a fishing expedition with a magnet?

 

i would try to get it out if you can.

 

I tried my best but couldn't find the piece that broke off. Also the Kat's replacement heater was too tall to fit properly. After struggling with it and a lot of cursing I tested the size of the o-ring compared to the hole the ring is too small to make a seal. Also the heater was touching the block. So I opted to replace it with an expansion plug instead. Fits nice and snug. Now to replace the radiator.

 

If mine ever leaks again I'll consider the expansion plug. Was it easy to locate? Meant for engine heat and coolant?

Too bad you couldn't fish out the wing. I'd suggest while the coolant is drained, open it up and apply a shop vac to the BH hole, see what you can suck out?

 

Sounds like you had the wrong replacement part, but if you don't need the block heater, thats not a big deal.
I wouldn't worry too much about the broken wing nut, it likely just dropped to the lowest spot in the block it could find and is sitting there. I'm trying to remember how the coolant flows, but I don't think something like that would move around too easily as it would be heavy and want to just sink.
The broken wing nut would have caused the block heater to shift causing the leak. If you replaced the wing nut, and the o-ring, you could put the old block heater back in. Just another option. Finding a wing nut to fit could be interesting though, unless the one from the new heater fits the bolt.

 

I considered doing a rehab on the old block heater, but with the corrosion on the heating element I just couldn't bring myself to put that back on the block. The expansion plug is a 1.5"+ I bought from O'Reilly for 7$. It was a snug fit when putting it in so it cinched up pretty tight after 2.5-3 full turns of the nut. Like I said I live in San Joaquin valley and we rarely see temps in the 20's. I also replaced the radiator yesterday, so I flushed the block while having the coolant drained and radiator off. The old unit was a 3 core. The "new" used one is a 4 core, guessing because the truck i pulled it from had ac, but it's in great shape with no leaks. I'm also planning on a turbo in the future so the 4 core seemed like the best route, especially for 100$ and a little elbow grease.

new radiator installed

old 3 core missing the 4th row

used a wire wheel and painted top to match rest of engine