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Hey guys, I have been helped greatly in the past with all your knowledge base and figured since I am stuck ill try again. I have a 95 3VZE engine that is leaking coolant behind the engine. I was doing some transmission maintenance when i realized the back of the motor is soaked everywhere with super clean green coolant. I have pulled the pleneum and after cleaning everything up i find that even though the truck hasnt been started recently it begins slowly pooling coolant right above cylinder 5 between the head and the lower intake manifold. I have removed everything above it that could possibly carry coolant. I didnt think water traveled up but i am starting to wonder. Is this possibly a head gasket issue? It is a solid 1.5 inches above the head gasket. coolant line below the intake manifold? Does anybody have any ideas? just dump some magic coolant stop leak in the radiator and turn a blind eye? Ill include some photos. Thanks in advance everybody. I am not unfamiliar with these engines so feel free to beat me up if I missed something simple.
just dump some magic coolant stop leak in the radiator and turn a blind eye?
NO!
No, no, no! Never, ever, ever. Bad bad bad.
/rant off
Don't ever use that stuff. It will clog up water galleys in the block, and then you wind up having to have the block hot tanked. Even that may not get it all.
I don't know the 3VZE worth a darn, since I have a 22R and a 22RE, BUT: It sounds to ME, for whatever it's worth, like a head gasket.
Remember that as the engine cools down, running or not, it draws coolant in from the recovery tank, Then as it warms up, even just environmental warming, like going from a cool night to a normally warm day, the cooling system pressurizes on up. The block, and heads, expand, in different amounts and at different rates, yes, but they all expand, causing the pressure in the cooling system to increase. It may not be alot, but it's there. If you have even a small leak in the cooling system someplace, coolant will come out. And as it cools off again, like the day goes into night, it will draw a little air in through the leak, and some coolant from the recovery tank.
Lather, rinse, repeat.
Like I say, I don't know that particular engine, but this is universal stuff. A thought: watch the recovery tank. If it's being drawn down, even slowly, well...
It's also possible that once it starts to leak, it may continue, like a siphon. And you know that a siphon can draw water up a pretty decent incline. So once it starts to leak out the small leak you have, it may continue until the water drops low enough for it to draw air, breaking the siphon.
I'm sure someone will tell you exactly what and where your leak is. Just hang tight for a little...
Pat☺
So, here are the promised photos, basically they are all the same photo but some closer to Mr Green's puddle and some further out so you can tell where we are looking. In the close up photo you can see my little glue wall to separate my puddle in half so i can tell which side it is coming from. You can see where it is pooling. any guesses on how it is coming upward through a metal gasket between aluminum head and aluminum air intake? Seems nuts
When I had this problem it was the coolant fittings on the throttle body leaking cause they were old and rusty, I bypassed it and never looked back. Definitely give that a look before condemning a head gasket.
When I had this problem it was the coolant fittings on the throttle body leaking cause they were old and rusty, I bypassed it and never looked back. Definitely give that a look before condemning a head gasket.
What did you do just run a hose under the throttle body with male ends on each end and leave the throttle body open? Seems like mine is on the passenger side rather than the driver side but as much of a pain as it is to unhook those coolant hoses on the throttle body every time the intake has to come off it might be worth a try
Its not the coolant pipe under the intake manifold lower section is it? That was leaking on mine and filled up what would be the lifter valley on a pushrod engine. The connection behind the water pump is just rtv, no gasket.
What did you do just run a hose under the throttle body with male ends on each end and leave the throttle body open? Seems like mine is on the passenger side rather than the driver side but as much of a pain as it is to unhook those coolant hoses on the throttle body every time the intake has to come off it might be worth a try
See all those sensors at the firewall end of your intake? These are all in the water jacket.
yeah I know it. I looked around the bottom of that assembly. the gasket is dry all the way around and no trail between the gasket and where my puddle is. dbittle I wondered about that coolant pipe. I think it may be a real possibility. Do you think it would fill up that whole gap between the two heads enough to come up right where that puddle is without spilling out the back just under those sensors? wait guys, I might have an idea. the sensors on the back are in the water jacket yes? so that means the lower air intake manifold must have water lines inside it yes? so it could very possibly be leaking between the passenger side head and the intake? or is that the purpose of the coolant line going from the front timing area to the back? Does anybody have a picture of the bottom of the lower air intake manifold?
Just a thought, probably mistaken, but: What is that object under the passenger side fuel rail? It's just outboard, and slightly forward, of the rear bolt that holds the fuel rail in place. Is that a sensor in the water jacket, or something totally unrelated? I was thinking it may be leaking slightly?
Just wondering.
Pat☺
Last edited by 2ToyGuy; 02-15-2020 at 01:45 PM.
Reason: more detail
Just a thought, probably mistaken, but: What is that object under the passenger side fuel rail? It's just outboard, and slightly forward, of the rear bolt that holds the fuel rail in place. Is that a sensor in the water jacket, or something totally unrelated? I was thinking it may be leaking slightly?
Just wondering.
Pat☺
Fuel injectors, sandwiched between fuel rail and intake..
I think the coolant pipe is a possibility. On my truck, which I picked up not running and have been slowly going through, the valley under the plenum was full of scale, rust, and corrosion. It looked like it had trapped a fair amount of water in there. I'm not sure where it would overflow though, because the truck had been sitting since 2013 and the valley had dried out. I thought having that pipe under there with just a rtv bead to seal it was a pretty sketchy design.
I would suggest renting a pressure tester from Autozone or equivalent. Clean all the previously leaked coolant off the the area in question, and then pump up the system to about 15-20 psi. It should then become obvious fairly quickly just where the coolant is coming from. That's the easiest way I've found to track down coolant leaks.. Plus, Autozone will give you your money back when you return the tester, so it's basically free.
That is starting to make a lot of sense. If the Lower intake has water running through it I would not be surprised if that is where it is coming from. I guess my next plan should be to pull the lower intake manifold then. Thanks guys! I do need to pull the timing cover to get that off yes? So I should probably just plan on draining the coolant and pulling the fan off?
I like the pressure test idea, myself. There is a hole in there somewhere. If you start pulling the system apart, it's not nearly as easy to pressurized it and start pinpointing the leak.
02-11-2020, 12:34 PM
