Coolant leak from front of engine near compressor housing

[soldave]

Got a coolant leak that's kicking my ass and wondered if you guys can offer me any ideas. So I've rebuilt my Evo III 4G63 engine and it's all running fine now except for the fact that when it's hot it is dripping some coolant. I've got under the car and had a look where the drips are coming from. They seem to be dripping down from the front of the main water pipe, just around the turbo coolant line outlet. Drops are coming right onto the crossmember in the middle of the car.

At first thought it was that hose so I've replaced it. Also in my rebuilt I replaced both large o-rings at either side of the main water pipe when I replaced the water pump. Have shone a flashlight up near those junctions and there is no trace of coolant there so I'm thinking it's not from there. Have also checked the heater hoses that join the main water pipe back near the intake manifold and those are bone dry so don't think it's there either.

All I can think of is when the previous owner blew the headgasket (and yes I did check the replacement head was not warped in any way) that he cracked the water pipe. And that when it heats up the metal expands and the crack opens up. anyone else got any other ideas?

Here are a couple of badly-taken pics showing where the drops are forming and coming down:

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[rlacasse1]

Where the waterpipe meets the water outlet hose for the turbo is it a rubber hose? Do you think maybe you could use a clamp and tighten it up more.

Oh, I can't see the pics or I would be more helpful. Work computers block alot of images.

 

[eeeewidner]

I agree with rlacasse1. The photos are really hard to make a good call. But just speculating look at the banjo fittings on the back of the turbo. They could be blowing coolant on the block.

 

[soldave]

It is a rubber hose which I have replaced and put new clamps on and tightened down.

 

[SrKegler]

Have you tried pressureizing the system. Should be able to find it that way.

 

[soldave]

No, and I don't think I have access to the facilities to do that. The car is currently not registered on the roads and, while my buddy's garage has a hell of a lot of equipment, pressurizing coolant systems isn't one of them.

 

[SrKegler]

Try making up a radiator cap with a valve in it. Use an air tank if you don't hve a compressor. Put pressure on the system like doing a boost leak test.

 

[soldave]

Try making up a radiator cap with a valve in it. Use an air tank if you don't hve a compressor. Put pressure on the system like doing a boost leak test.

Coming soon to a forum near you: thread entitled, "Coolant still leaking, face now looks like Freddie Kruger after coolant burnt skin off"

 

[knochgoon24]

You don't pressure test coolant system while it's hot.

 

[soldave]

Replace with "blinded by mist of pressurized coolant entering eyes". Apparently my poor attempt at humour failed.

 

[SrKegler]

, never meant to pressure test it while hot, do it while cold. All we're doing is creating the same pressure in the system that he's getting while the engine is hot. Hot water expands, creates pressure. Easiest way to find water leaks.

However, I stand corrected by the experts. Was just giving alternatives since he can't get to the shop.

 

[soldave]

No that's cool. I understand what you mean now and might have to try that.

Someone's also mentioned the plug/bolt thing on the front of the block that you can see just to the left of centre in those pics. I suppose it could have been accidentally loosened and would cause a leak down the front of the block and onto the water pipe.

That'd be a real nice simple fix if it was.

 

[gen2allday]

QUESTION??? which is cheaper??? Replace the hose or the engine/turbo? Replace the hose its like 2 dollars. Go to a junkyard and take clamps ...or buy them.

 

[soldave]

QUESTION??? which is cheaper??? Replace the hose or the engine/turbo? Replace the hose its like 2 dollars. Go to a junkyard and take clamps ...or buy them.

What hose are you talking about? I'm worried that the main steel water pipe that runs along the front of the engine is cracked. Methinks it'll be a little more than 2 dollars.

 

[SrKegler]

If it is, try having the hole brazed. Those pipes aren't cheap.

Sorry if I sounded cranky in previous post.

 

[soldave]

Not at all bro. You were trying to help

Looks like the pipe would be about $90 or more. The plug at the front much cheaper to sort out

 

[soldave]

Amazing what the right tools can do? My buddy who has much more equipment and knowledge than me came over with his portable radiator pressure tester. Fitted it up and within about 10 seconds we found exactly where the leak was coming from. Right on the inside of the corner where the water pipe comes around the front of the engine there were 3 cracks spurting water out.

So at least I know for sure what needs to be replaced and so tomorrow I'm gonna drop the turbo again, and on Monday I'll order a brand new waterpipe.

 

[SrKegler]

Chuckle, chuckle, at least my post stopped your from spraying hot coolant in you eyes. Glad you found the problem.

 

[soldave]

Thanks man. Will try to post up a project thread sometime soon.