Coolant dripping from under crank pulley

floridaZ · 12-14-2008, 01:39 AM

First, a little background on the Vette. It's an 84 with the CFI that I've built up with new heads, a 383, chip, exhaust, cams, and all that fun stuff. The engine was originally rebuilt at 158,XXX miles. Then the tranny shop dropped a few bolts in the intake when they rebuilt the tranny, so I bought the stroker kit and had the block machined (the valves were shot, the head and pistons scarred, and the cylinder walls scored on two cylinders). I forget the mileage when that happened, but it was after the initial break in. Since then I have broken in the new engine properly and the car is sitting as I type this with 171,242.1 miles.

Okay, well about a month ago I had a problem with the Vette. The thermostat stuck and the car overheated. Unfortunately, I got to find out that the stock gauge maxes out at 299 degrees. Anyway, once I found a place safe to pull over, let it cool down, and got it home, it seemed to drive fine.

The thermostat still would stick so I pulled it, flushed out the system, and put in a new one. Car ran fine and drove fine as long as the thermostat would open, which it would not always do. Then last week, I was going to pull it out and take it for a drive since I hadn't drove the thing except for once to make sure that the engine ran okay, and my father tried to drive it to work once (and didn't get far). So I let the engine heat up, and opened the garage door. The Z was in the way so I shut the car off so I could go get the Z's keys and move it. But when I shut off the engine, it dieseled for about a second. So that scared me off from driving it, so I let it sit until today (technically yesterday).

So I pull it out of the garage today, determined to find out what was causing the car's issues. That's when I get under it and notice that there is coolant dripping on the ground. So I start crawling around and see that it is dripping from the crank/pulley. I thought that it was the water pump seeing as it is right above it, but when I jacked the car up and started looking around, I couldn't find any evidence of coolant leaking from there. So I put the car back down, and run it for a bit. I then pull off come of the accessory pulleys to better be able to see the water pump. No dice, no sign of leakage. So I pull the Vette into the garage again and pull the intake off, so I could see the valley. I didn't find any evidence of a valve gasket blown, or any evidence of leakage in the valley.

So my father has looked it over, and thinks that I have either a cracked head, or a cracked block. There isn't any coolant burning off of the manifolds, so it's definitely coming from the front of the engine. And the radiator and hoses appear to be perfect, so I doubt that coolant is coming from them. I just can't see where the coolant dripping off of the crank pulley is coming from...

So I guess my question is... any ideas? I'm hoping that it isn't a cracked block. The heads are aftermarket so if one of those were cracked I wouldn't care, but I have quite a bit of money in the block itself. And the Z is getting a new driveline and carpet soon, so I don't want to pull the Vette's engine unless I am certain that the block is cracked, or needs some other maintenance/repair that requires pulling the engine. So does anybody have any ideas of what else it could be, and any suggestions on how to check it?

gmjunkie · 12-14-2008, 06:53 AM

Yeah,
1.My guess is that the water pump is leaking out of the weep hole in the water pump!!
2.My second thought is you also have a blown head gasket or cracked head!!
Or Both!!

It's not uncommon for a thermostat not to open when there is a air lock in the system!!
Air locks are usually caused by "Low Coolant" in system!!Leaking Reservoir Line, Leaking Water Pump,Leaking Hoses,Leaking Expansion Plugs,Leaking Radiator,Heater Core,Blown Head Gasket,or Cracked Head!!

PS,Check your Radiator cap, reservoir tank and lines first!! If there is a leak and the engine can't draw coolant back on cool down,it will create a air lock in the system over very little time and over heat!!

grumpyvette · 12-14-2008, 08:01 PM

gmjunkie
is more than likely correct, this might help
link

Ms. AntiVenom · 12-15-2008, 03:37 PM

I was going to say weep hole too,

Well thats what I hope it is!

floridaZ · 12-15-2008, 11:42 PM

Well, I checked the entire coolant system before I left for work, and it all seemed to be in good order. Is there a way to check the weep hole without starting the engine? The pump is relatively new, and if the block is cracked I don't want to run the engine any if I can help it. Simply because it appears to run fine doesn't mean damage isn't being done... and I'd like to be able to swap internals to a new block if this one is cracked.

(I'm assuming that you can't just stick something up the weep hole and see if it goes through anywhere. That would be too easy...)

gmjunkie · 12-16-2008, 05:22 AM

Quote:

Originally Posted by floridaZ

Well, I checked the entire coolant system before I left for work, and it all seemed to be in good order. Is there a way to check the weep hole without starting the engine? The pump is relatively new, and if the block is cracked I don't want to run the engine any if I can help it. Simply because it appears to run fine doesn't mean damage isn't being done... and I'd like to be able to swap internals to a new block if this one is cracked.

(I'm assuming that you can't just stick something up the weep hole and see if it goes through anywhere. That would be too easy...)

I'd pressure test the system,Hot and Cold!! Advance or Auto Zone should have a cooling system tester for loan or rent!!

It's not a hard testing procedure,just requires some time!

floridaZ · 12-18-2008, 12:18 AM

Hmm, I might have to do that. I'm currently working on the Z so it will stop being a pain in the ass, so I can get to working on this pain in the ass.

floridaZ · 12-21-2008, 12:17 AM

So I've started slowly taking off some of the engine stuff. Once I get a new driveshaft for the Z I'll pull the entire engine and disassemble it. With a lot of the stuff off, I've found what *might* be a leak pattern from the water pump, but I'm probably going to take everything apart and check the block, just to be safe.