Hello fellow car lovers,

Well I got me a coolant leak somewhere and I'm hoping these pictures will help me find where it may be coming from. I know it's not the water pump because it's coming out towards the back of the engine and dripping down just in front of the Oil Filter. It looks like a very very slow leak, I drove it around today and it's not like anything is gushing out, just a very slow drip on the garage floor. L
I know this sounds dumb, but can coolant leak out from the valve covers? This is the only spot where I can see that there is a lot of fluid, I attached a picture of the very last spark plug on the passenger side.

Thank you for all advice and suggestions.

 

I've seen the intakes leak on the rear on Chevy 350 I would imagine it could be the same for olds also check your heater hoses could be one of those as well
Good luck

 

Yeah, I'd consider heater hoses, hot water valve, and then intake manifold.

- Eric

 

Coolant should be nowhere near the valve covers. If it actually were leaking from under the valve covers, you'd have a much more serious problem than a coolant leak!

But I'm with these other guys. It's probably a leak from a more benign source, and it's just running down to where you're seeing it.

 

Freeze plug?

 

Yes the first picture is coolant leaking from the freeze plug,the second picture looks like an oil leak.

 

You can go to O'Reilly's and borrow a pressure tester and pump up the cooling system and probably find the leak. I did that a few years ago on a Corvette I had. I am betting on the heater hose with a small split in it.

 

This is exactly what I'm seeing.

 

Thanks for the replies. I will look more at it tonight, I checked all the hoses and I couldn't find anything, but again I could be missing something.
It seems to only leak after it has been running if that makes any difference.

 

changing the freeze plugs pretty much requires an overhaul correct?

 

Most parts shops have a UV dye that you add to the coolant to find leaks. Don't bother with the $20 UV flash light they offer .. the dollar store usually has those little counterfeit money keyfob lights that do the job just as well. I spend enough time looking that I got a black light party bulb and stuck it in an old worklamp for the job. Forget the fancy glasses too ... just about all safety glasses today have UV protection on them. Pour the dye in, drive about for a couple of minutes at sunset, then stick your lamp underneath and look for the glow. No farting about, you'll spot your leak in seconds ... I usually find there's more than one to deal with while I'm there.

I've used this for coolant, oil and fuel leaks. I believe there's a dye for brakes too ... but I haven't had to use it. Just having someone stand on the brake pedal is enough to announce to the world where that leak would be.

 

Antifreeze that I've used already has some UV pigment in it.

- Eric

 

If this is an A/C car, my money is on the heater control valve. How about telling us year, model, engine, and A/C or not?

 

I ve done some freeze plugs on 3.8 and no it did not need a over haul, but it wasn't very easy in the car

 

Hey Joe,
It's a 1972 Olds Cutlass supreme with a 455. Automatic Transmission and A/C.

 

heater control valve was the culprit on mine this summer..leak was in the same area.

 

Yeah I looked all around there and couldn't see anything at all. I started the engine and let it run for a few minutes, but maybe I need to actually drive it around then check it.

 

I would think you would just need to get it to operating tem and the cooling system pressure would then force the water out. Freeze plugs have nothing to do with having to rebuild the engine. If it is one in the back you may have to pull the engine up to replace it though.

 

Just get a pressure tester (you can probably borrow one from a chain auto parts store) and pump it up to 16psi and you'll see the leak if there is one.
I prefer this to warming it up, as you can get your hands into tight places to feel for coolant when the engine is cold, where if it were hot, you'd burn yourself.

- Eric

 

Good point, you can probably borrow one from an auto parts store.

 

Picture #1 first post am i seeing something or what?that is the freeze-core plug rh side of block just above the motor mount, right.Not to much fun doing in vehicle.

 

this is just a guess but check the heater core also.

 

Lets hope it's not the head gasket....I thought that was going to be where mine was coming from because I hadn't re-torque my heads and there aluminum.

 

It COULD be a lot of things. Troubleshooting 101 is start with the easy/obvious things first. Heater hoses are the most likely cause. Heater control valve is no. 2. Freeze plug, intake, or head gasket are possible but unlikely causes. Heater core leaks show up as a puddle in the passenger side footwell, not under the hood.

 

My heater hose and control valve only had a few hundred miles on them,so no way it was going to be that......sure enough it was the valve thank goodness. Replaced more new parts this last year than I'm used to,mostly seals.Might need to drive the car more.And when your date starts complaining about wet shoes ya pretty much know what that's about.

 

Yeah, I'm 99% sure it's the freeze plug above the motor mount. I can see it slowly leaking from there.

Now I just need to figure out how to change.

 

I don't know which is easier, removing the fender and wheel well or pulling the engine. Choice is your based on what else you need to do while your in there, MAW's.

 

My feeling, without seeing the car or being right there, is that you should be able to do it by pulling the fender liner and the exhaust manifold, and then jacking the engine slightly and removing the motor mount. Unless you've got a shop and helper that're ready to go, this is probably easier than pulling the engine, but if you had everything waiting and had experience pulling engines, it might be a toss-up.

- Eric

 

If you can't or unable to replace it in car, they used to make a copper expandable one you can use easy to install.Do not use the rubber one.

 

Another thought. If you are willing and able to pull the engine, you could change all of them. If one is deteriorated and leaking, the others are probably not be far behind.