COOLANT dripping from exhaust.. AGAIN

Raptor660

New member
So I just finished the head and everything... and coolant still drips from my exhaust. When I had the head off, I could actually see where it had been leaking from the water jacket holes to the cylinders on the back 2. I had the head milled by good shop, cleaned the holy crap out of the gasket surface on the block, used expensive gaskets, used NEW head bolts, torqued them to spec... and still water drips from my exhaust...

Help me out, SteelHeadz... Does this mean my block's cracked somewhere? Actually I suppose since it's making its way out the exhaust, it would have to be a cylinder head crack near one of the exhaust valves?

Anything else that could send water dripping out my exhaust every time the engine runs?

Nothing like getting a motor running after 3 weeks and a crap-load of money.. only to find out it may have all been for nothing!
 
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Ok, first off, are you sure it's antifreeze thats coming out of your exaust and not condensation from sitting overnight?. if you have taken the cylinder head to a reputable machine shop, i would have to think that they would have checked it for cracks prior to machining the surface. one way to test the cooling system is to pressure test it. you can find one of these at Napa or a local parts store. your Radiator cap will tell you what is the Max. operating pressure the system holds. i beleive it's 16PSI. pressurrize the system and watch the bottom of the engine and the floor for any drips. follow the source and isolate it. if it comes out of the exaust then that verifys that you have a leak on either the head or the block. its possible to find a cracked block but it's not common. if the coolant does leak on the exaust, look for drips from the muffler weep hole.. let me know what you find out.
 
Yeah, it's definitely anti-freeze. When the motor starts and runs, after about 30 seconds to a minute, it starts dripping from the weep hole in the muffler then the tailpipe soon after. At first I was hoping to God that it was just condensation from sitting, but even after running the engine for quite a while at full temp it still has a steady drip from the tailpipe. It's worse now than before I did the head gasket..lol. My luck..
 

No, it seems to stay the same every time. I mean, I'm sure it's going down at least a little because of the steady drip out the tail pipe... but it's definitely not noticeable by looking at the coolant reservoir. If I hadn't caught the drip out of the exhaust, I probably wouldn't have ever caught the issue.
 
I would have thought that if it's blowing out antifreeze then it would also blow out smoke.:???: sometimes the condensation takes awhile to dissipate with the consideration of the ambient temperature and humidity in the air. no antifreeze mixing with the engine oil?
 

No antifreeze mixed with oil. I was thinking it was condensation left over from before as well... but I've run it over and over and got it hot, then shut it off... and everytime same thing.
 
I would have thought that if it's blowing out antifreeze then it would also blow out smoke.:???: sometimes the condensation takes awhile to dissipate with the consideration of the ambient temperature and humidity in the air. no antifreeze mixing with the engine oil?

I forgot to mention... ambient temp and humidity wise: today was around 85 degrees outside during the last test period with around 7% relative humidity. Gotta love the desert
 

Thanks for the help guys. I'm going to go let it run for awhile longer and hope to the Jeep God's it stops. What has me pretty discouraged though is the fact that the leak is faster now than before I started...

Originally it was a drip every few seconds, and now it's at about 1 per second. I guess the one difference I can think of is before the head came off it was pure 50/50 antifreeze and now it's mostly distilled water since it's just a mixture I'm running til the final flush...

Back to the garage... just be glad you're not my neighbor! lol
 
So here's what I found. This time around the leak out the tail pipe was slower because the Jeep's on a more level surface. I was getting a drip every 7-10 seconds. After 20 minutes of idling, the drips stopped at both the weep hole and the tail pipe, however the exhaust was so hot to the touch before the weep hole that if there was still water getting in, it would evaporate before it could leak... I guess I just have to wait for it to cool then try it again.
 
Man down... get the grenades. It's about a leaky SOB. Giving it throttle seems to increase the flow-rate of the leak, so I'm thinking I'm pretty much SOL. I'm gonna let it cool and try it a couple more times.

Anyone think I could run this thing for maybe a month or so (as long as the coolant level is maintained, of course) while I build a new motor? I keep getting conflicting stories. Some people say it's horrible to run it in this condition with coolant making it's way into the exhaust, and some people say it's fine to drive it around as long as it doesn't get much worse.

It's one thing if it's my ride and it breaks down... oh no, right? But I don't really want my girl and my baby driving around in something that's going to break. My job isn't really one where I can just pull the old "Hey, I gotta run and do something. I'll be back in an hour or two" lol

Any opinions?
 

Not knowing the severity of the leak. i would have to say ,Don't run it. the failure of your O2 sensors and Catalyst is inevidable when the Ethylene glycol crystalizes on these components. The only course of action that you can do right now is to remove the head again to inspect both the Cylinder head and the block. a possibility could ba a faulty head gasket or a piece of trash could have fallen on the gasket during installation.
 
I should have had the head tested... The shop said they didn't see anything, so I'm guessing either they missed something or it's the block. I was really careful with the gasket and it was a pretty decent fel-pro if I remember right. I made sure that both surfaces were spotless (block & head.. took a couple days), everything was covered with plastic until right before it went on, and I was extremely careful to make sure nothing fell on the gasket before the head went back on. I'd say the gasket only sat in place on the block for about 1-2 minutes before the head went right on. I thought taking my time and doing everything to spec would save me on this one, but it looks like I might be dealing with some demons out of my control now.

I have a buddy with a 4.0 from a 95 Cherokee, but I think the 99 had a better head, didn't it?
 
I've taken a picture of a puddle left from an 06 Jeep wrangler unlimited with a 4.0. Iphone's are not the fastest when it comes to sending pictures to an e-mail account so i can show you for comparisson on your part. I'll post it hopefully tonight.
 

I've taken a picture of a puddle left from an 06 Jeep wrangler unlimited with a 4.0. Iphone's are not the fastest when it comes to sending pictures to an e-mail account so i can show you for comparisson on your part. I'll post it hopefully tonight.

A puddle from just normal engine warm-up condensation?
 
Nice.. that would be cool so I can compare. I think what I also need to do is dump the mostly distilled water from the cooling system and add straight 50/50 anti-freeze. When it's anti-freeze I can let it pool up in my hand and smell it... that's how I knew it was the cooling system leaking into the exhaust before. Now there's so much water in there it's hard to tell for sure.. I think I can make out the slight glycol smell from the little bit still in the mix though.. kinda discouraging.
 

These 2 pics. was taken this morning with a 10-12% relative humidity @ a 68 Degree temperature. Idle time for 3 mins. only. the one on the Left side is off the tail pipe and the one on the right is off the Weep hole of the muffler and flange.
 

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