Lots of coolant leaking into exhaust...when cold!
 

Hello all, I just rebuilt an egine and it is leaking coolant in a way that has me really confused.

Before we even start it up for the first time, we go to add coolant and after the first gallon, we come back a little later to add some distilled water and soon after that we find coolant leaking out of the EXHAUST!! There was also some seaping out of the (new) gasket between the turbos and the manifold and one of the actuator arms.

WTF could be causing this? We used the rotary aviation seals for the inner o-rings. I am pretty sure it isn't leaking there at the o-rings because of the speed and volume of the coolant that leaked. It didn't just seap out slowly, like you would expect from a o-ring being out of place or cut, it was pouring out between the cat and the cat-back.

Is there any way that the coolant from the turbo to leak in that sort of fashion?

The only guess I have is that when we put the housings in the hot vat that it corroded the aluminum around the exhaust sleeves and chewed into the water jacket, because I scraped of a good deal from around that area before we put the motor back together.

Any help or troubleshooting ideas from you all that have some rebuilds under your belt would be appreciated, this is just my second.

never have seen a set of turbos leak throught the coolant jacket. does not mean it is not possible but it sounds like the coolant seals are not right

I wonder if it is actually leaking from the coolant nipple located on the top of the rear iron - the one that normally connects to the throttle body.

Or another way to say it - the coolant nipple that is located near the firewall, on the passenger side.

That nipple is basically at the highest point in your coolant system [other then the fill neck], so it will start to leak from there only when you have filled the coolant system to capacity OR if your car is say, still nose-up on jackstands or something like that, where coolant could start to run out of that nipple...

Check your oil for coolant, it sounds like you pinched a coolant seal above the oil pan. If it were open enough I think coolant could get up through the egr port into the exhaust. I just did the same thing, mine was not leaking as bad. My car ran but the oil pan was getting pressurized and lots of coolant in it. A mix of coolant and oil was getting through the passage in the housing that connects to that port on the exhuast maniflold.

Took it back out and found that one of the water seals had been torn to pieces, getting wrapped around a tension bolt.

I don't know anything about the coolant passage for the turbos, so can't comment on that.

I really don't think a coolant seal being out of place would cause the volume of coolant that was leaking. This has got to be a pretty big hole somewhere. the engine was tight when we built it, solid sounding, no leaking noises when we spun it through by hand. anyone have any other ideas???

We are going to tear the turbos off this week and plug the turbo coolant lines, then fill the engine up, see if it is leaking from the engine. I still think it has something to do with the corrosion around the exhaust sleeves from the hot vat that the housings were in. Who knows.

Please let us know what you find, I am interested in what it could be.
I suppose you can remove the turbos, block off the coolant lines to the turbos and just watch the exhaust ports after you fill it completely. Do you have any water in the oil?

Maybe you mixed up the coolant return line with the vaccuum line that goes to the pcv (on the little elbow at the front turbo). Farfetched even though they are near each other, but it would deliver the amount of coolant you describe to the exhaust.

Turbos are off of the car, didn't have time to test today, report will follow this weekend.

Tore the block down today. Sure as shit is was the damn rotor housings. Both of em, one hole in each straight through the exhaust port lined right up with the hole in the exhuast sleeve there on top of the port. About half the diameter of a pencil. Re-freakin-diculous. Just chewed right through the aluminum.

I'm pretty sure the damn hot vat that we used at the base's auto hobby shop did it, turned to perfectly good housings into $500 paper weights.

My buddy isn't to happy about having to spend 1G on housings, and I'm pissed I didn't see it when we were putting it all back together. Oh well, the only thing we would have saved is some time and the water pump gasket, everything else is going to be reusable.

Thanks for the help fellas, time to clean again, reassemble again, and reinstall...again.

That sucks ass. I have always used a parts cleaner and done everything by hand. Takes more time, but less chance of things getting damaged. How many miles were on the rotor housings? If that happened, they might have been on their last legs anyway.