2018 - TDP's 22nd Anniversary
What's New: | Feature Articles: | Product Reviews: | Member's Area: | Subscribe:
Duramax 6600 Diesel Page | Advertiser's Section | Classified Ads | Photo Album | Diesel Books, GM Licensed T-shirts

Go Back Forums > Other Diesel & Truck Related Forums > Diesel Conversions
Register FAQ Members List Photo Album Mark Forums Read

Diesel Conversions Convert gas to diesel, or convert to a 6.2/6.5/Duramax/Cummins/Navistar/Isuzu/Perkins/Detroit/or ... diesel engine. Go here to see completed projects, works in progress, share your conversion or ask the experts.

Thread Tools Display Modes
Old 07-08-2017, 05:39 AM
Gusshr Gusshr is offline
Join Date: Jul 2017
Location: USA, FL
Posts: 2
Default Little turbo leak..........Overhaul the engine?


Finished oil changes heat exchanger cleaning, and was on for the last item of maintenance "a small turbo leak" that is causing smoke in the engine room when run hard (the oil burn on the outside of the riser) because the gravity is guiding the dripping oil underneath the riserīs blanket on this 8V71ti with 3100 hours. (it leaks only after it cools down not during run)

So pulled the turbo for rebuild, and as you can see from the pictures there is damage to the exhaust side and the turbo guys at metro diesel in Miami said it cannot be balanced, I called my mechanic and he said STOP, do not get a rebuild one as the new one will be damaged too. Lets look in the engine air box hatches to see whats wrong.

Now this engine smokes very tiny white smoke on startup but disappears after 5 min run. Otherwise it sounds fine and had no other issues. A high crank case pressure was detected on both engines actually up to 3.5" at the time of the engine survey on this boat.

I asked around and everyone told me as long as the engine starts right up and does not smoke and as long as it runs hard fine then donīt worry about that.

Knowing some about the engines mechanics, I had a discussion with my mechanic (who seems little pessimistic) that if we found anything wrong with further investigation then it will be a major overhaul, and he confirmed.

Now the question is: other than this small leak and the fact that we found dinged exhaust turbo blades as you see from the pictures, do I really wanna pursue this problem to the source and potentially perform a major overhaul? Would you do that too?

The mechanic says you put a newer turbo it will be damaged again, and maybe you end up with broken block. My logic tells me a piece had passed by that turbo ( I had no good history on this boat), I am not sure if this damage had been there for years or happened in the last 100 hours that I have used this boat for so far. Could another piece pass by? yes anything is possible. Could another damage happen anytime? and my answer is yes this is an engine from 1972 I am not going to make new again.

Please advice on what you would do?

Attached Images
File Type: jpg IMG_0101.jpg (91.2 KB, 10 views)
File Type: jpg IMG_9525.jpg (91.0 KB, 9 views)
File Type: jpg IMG_9671.jpg (83.8 KB, 9 views)
Reply With Quote
Old 07-08-2017, 09:33 AM
Yukon6.2 Yukon6.2 is offline
Join Date: Dec 2003
Location: Yukon Canada
Posts: 955

I have had a few Detroit's over the years.
Myself i would replace the turbo.
I don't follow the logic of how the block could get broke by adding a new turbo.How is the supercharger? That should show you if there are more bits floating around.Mine had a screen before the supercharger to catch bits before they went through it.
The 71 series of Detroit's are one tough engine.If the airbox's are clean go with a new turbo and let her rip.
I was told by a senior trucker before driving a Detroit you need to slam the door on your hand so you are pissed off and drive the crap out of the truck.
I had one in my fuel truck that leaked oil out of the air box's when it was started.It would leave a 6" puddle each time it was started.Another old-timer told me to stop using multygrade oils in it.So i switched from 15W40 to straight 30W the puddles disappeared to a few drips at startup.
The scariest thing that i was witness to was when my mechanic changed injectors.He didn't get the rack set right and the 671 ran away.Tanker was about 1/2 full and all i could vision was a huge explosion in my shop.He was trying to smother it with a piece of plywood over the intake.I managed to spin off the fuel filter and got it shut down before it exploded.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews
Reply With Quote
Old 07-08-2017, 03:53 PM
Gusshr Gusshr is offline
Join Date: Jul 2017
Location: USA, FL
Posts: 2

The broken turbine is on the exhaust side. The supercharger should not be damaged unless a foreign object was sucked into the engine and then through the Supercharger, and then the cylinders and then the exhaust then the turbo.

My mechanic actually was mentioning that since the foreign object should have generated from the piston area through the exhaust, that there is a potential of additional material getting discharged and potentially could damage the block itself (because of a cylinder that may get stuck or for other reasons).

I appreciate your response, I think at this point we're going to open the hatch covers and take a look inside. I believe the big question would be what to do if I find that one of the rings is broken, given that the engine doesn't have any other symptoms.
Reply With Quote

detroit, overhaul, turbo

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -7. The time now is 03:49 PM.

Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright 1996-2018 by - All Rights Reserved