Turbo exhaust leak, how serious?

[Westfield 11]

So we are in Marathon for another week and will have to vacate our slip next Wednesday. I have a motor issue that I want to get sorted before we cross to the Bahamas, but I don’t know if I need to get it fixed here in Marathon or if we can go north to Stuart, Lauderdale area where it will be cheaper and there are more service choices.

The problem is an air leak from a turbo that is putting out soot at the flange where the turbo connects to the exhaust pipe. The clamp was a bit loose and I snugged it up, but I know the turbo needs to be demounted, have the surfaces cleaned and then be reinstalled. I would start the job today, but I am concerned about breaking hardware and getting stranded with only one engine and I would prefer to assist a tech as opposed to doing it myself for the first time.

Like I said, I have snugged up the clamps, the large one on the compressor flange was not loose, but I was able to get 1/4 turn on the bolt. The smaller clamp was definitely loose and I got perhaps a turn and a half on it. Is it safe to run up north at 1050 rpm to get somewhere we can have it repaired or are we stuck here? I have the turbo blanket removed now and there is no oil on it, just some scorching. Should I reinstall it for the trip north or leave it off. I intend to clean the soot off to be able to see if I have stopped or slowed the exhaust leak, but is there anything else I can do? I would prefer to leave the turbo attached to the engine exhaust manifold with the bolts as I don’t want to break one and disable the engine until I am somewhere I can stay while I wait for parts.

I guess what I am asking is if a exhaust leak from the turbo flange is enough to keep us from running that engine for a couple or three days at low rpm to get out of the Keys. And how can I check to see if I’ve minimized it by tightening the clamp?

[SeaEric]

Aside from the mess that the soot makes in the ER, you do not want your machinery ingesting airborne soot. It eventually makes the engines self destruct. One more after thought - if that clamp breaks and the turbo comes loose you've really got big trouble. Inspect that clamp carefully and monitor frequently while underway.

[sgharford]

Yes, beware of removing turbo from exhaust flange. I removed mine (1976 Cummins 903) a few years back to facilitate replacing exhaust hose. The flange on the turbo side crumbled in several places, rendering it useless. Thanks to Avenger I was able to find replacement turbos. Turned into big job.

There is a special, and expensive, high heat sealant you are supposed to use on the Turbo to Exhaust Flange union. I tried finding name of in my archives but am at a loss. Perhaps you could carefully remove clamp, spread this sealant along outside of union, and reassemble? Wish you Best.

[captcrunch]

I had a turbo and other exhaust leaks and engines sucked up soot. Expensive repairs try to get fixed asap

[racclarkson@gmail.com]

May seal itself when it heats up.

[Westfield 11]

What is the best way to check it? Run the engine without the blanket and use a piece of paper along the flange to show gas leakage? I know better than to use my hand to look for 1500 degree exhaust gas leaks, but what do you guys do?

[racclarkson@gmail.com]

What is the best way to check it? Run the engine without the blanket and use a piece of paper along the flange to show gas leakage? I know better than to use my hand to look for 1500 degree exhaust gas leaks, but what do you guys do?Clean the blanket. Clean around the turbo. Take a picture if need be. Run the boat and check the blanket. It may very well leak some on start up and be good the rest of the day. Still needs addressing, but manageable. The blanket will tell you.

[Jammin']

There is a special, and expensive, high heat sealant you are supposed to use on the Turbo to Exhaust Flange union.

I think it was Silkolene 762.

https://www.silkolenestore.com/product/silkolene-762-hi-tempjointing-compound/

[sgharford]

I think it was Silkolene 762.

https://www.silkolenestore.com/product/silkolene-762-hi-tempjointing-compound/


Yes! That is it.

[steve c]

I had a similar issue two years ago and found the v-clamo was fatigued but not broken. Replaced the clamp and all was well again. Not a bad spare part to keep aboard and not all that expensive.

[oceanjake]

x2 on the silkolene. expensive stuff to say the least but it works. My opinion is that leaking exhaust is bad all around. Bad for the engines to ingest. Also a potential carbon monoxide hazard depending on the turnover rate of your blowers. I know it's not "pro", but you can remove that clamp completely and smear in a product called JB Weld High Temp. Just smash it into the cracks and put the clamp back on while wet. One would think that this would make a permanent bond and you'd have trouble in the future but this is not the case. One whack with a rubber mallet and the JB weld will crumble right off and you can do a proper seal job with a fresh clamp and silkolene (which by the way is not required to make the turbo seal but is merely an aid if the mating surfaces are not perfectly parallel). I have used the JB weld in a pinch to keep gases at bay for a few trips in a pinch. Safe travels.

[SKYCHENEY]

Never had much luck with Silkolene and way too expensive. I use the exhaust flange sealant that Caterpillar sells. It comes in a pint can made by 3M. Good stuff.

[Briankinley2004]

Loctite MR2000 is the sealant Cat now sells. 3M no longer makes their products. If your engine is a Detroit some of their clamps are getting hard to find. I recently went through this and finally found the clamps used for my 12V71's. I used the Loctite and so far all is well. Here is the link to the original thread

https://www.samsmarine.com/forums/showthread.php?31814-Turbo-Leak-12V71/page5

[bigbill]

permatex makes an exhaust sealer that is rated up to 2000 degrees just like the cat stuff, its about 8 dollars a tube at any auto parts store. just used it on my john deeres. i have not run the boat hard yet but running her at 1500 for about 10 minutes and there is no sign of leaking. i will be taking her out in the coming weeks and will report back what it looks like after an extended run on plane.

[kelpy]

All exhaust leaks at the turbo or elsewhere are serious no matter how small. That being said, I would remove the large clamp, remove the elbow and clean all of the mating surfaces until they shine. Visual inspect the surfaces for any burned areas. Reinstall the elbow onto the turbo using a new clamp. I'm not a fan of using any sealant but it can't hurt either. Start her up and recheck for leaks. If you do run it under load to test, reinstall all of the insulation before doing so.
If it still shows evidence of leakage, there are new exhaust parts in your future.