Jay-D Posted June 20, 2006 Share Posted June 20, 2006 Hey guys we got a 6L in with a melted piston head Doess anyone know what causes one piston to burn up like that? It also looks like a valve h9it the piston but I dont think that was the reason and something probably got stuck in the valve as the piston started to come apart. Any ideas? thanks Quote Link to comment Share on other sites More sharing options...
HGM Posted June 20, 2006 Share Posted June 20, 2006 If its #3 its probably an overboost.. If you find a loose or leaking injector it can do it as well.. Check history and do your tests.. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted June 20, 2006 Share Posted June 20, 2006 I love it when you guys raise more questions with your answers! But I am stumped on this one. How can an over boost situation cause one burnt piston and why would you say #3 specifically? Quote Link to comment Share on other sites More sharing options...
LARRY BRUDZYNSKI Posted June 20, 2006 Share Posted June 20, 2006 Have you looked at the piston cooling nozzles? (3C3Z 6C327 AA) We haven't seen one on the 6.0 yet, but if it's just one piston it's worth a look. Quote Link to comment Share on other sites More sharing options...
HGM Posted June 21, 2006 Share Posted June 21, 2006 I love it when you guys raise more questions with your answers! But I am stumped on this one. How can an over boost situation cause one burnt piston and why would you say #3 specifically? You know, I'v easked that very same question..... It seems that a sticking turbo, overboosting at the wrong time will effect #3 before the others.. Kind of like #5 and 7 will be dusted first on a 7.3L.. I dont have a good aswer for you, but I've seen several and hotline will likely tell you the same.. I had one that had an engine replaced come back with the same concern, #3 melted after 2,000mi.. After replacing the engine for the second time, we checked boost pressure and got 29psi from a sticking turbo, not all that much, but timing is everything... Quote Link to comment Share on other sites More sharing options...
Jay-D Posted June 23, 2006 Author Share Posted June 23, 2006 Thnx guys it is number three that burnt and bad too! I guess I will have to check the turbo or dont you think that a new long block deserves a new turbo even if you suspect it's causing problems? I dont want to relace this engine again on the same truck or have to replace the turbo after putting this thing back together /forums/images/%%GRAEMLIN_URL%%/banghead.gif Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted June 24, 2006 Share Posted June 24, 2006 Jay, We have an engine in with a burnt piston in cylinder number 3 right now as well. It scored the cylinder badly so we are installing a long block which does not come with a new turbocharger. The tech is half-way through the job so I thought I would open the turbo and have a look. What I found was almost shocking! It's the turbo in the Turbo Reconditioning post. This is definitely what I call visual confirmation that this turbo was not operating properly. As far as I am concerned, this gives full credibility to HGM's post on checking the turbo for over-boost and the cylinder number three phenomenon. /forums/images/%%GRAEMLIN_URL%%/notworthy.gif Quote Link to comment Share on other sites More sharing options...
ErickBaker Posted June 28, 2006 Share Posted June 28, 2006 I have one in my bay now pistons number cylinders 2,3,and 5 burned. Cylinder 8 was just starting to burn. Cylinder 2 is the worst with the swirl chamber eroded so severely it is oblong and one of the valves burned. Now this thing just had a turbo and injectors number 2 and 6 replaced up in jersey less than a week before I received it. When I got it the turbine wheel was sheared off of the "new" turbo. Replaced the turbo and the truck had a slight miss off idle. Then the truck proceeds to run away for about 15 seconds, so that made further diag a little risky in my opinion. I was just wondering what the hell happened and if there was anything else I should check other than turbo boost and fuel psi when I put the new long block in it. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted June 28, 2006 Share Posted June 28, 2006 Add one more to the tally! Just diaged another 2004 with low compression cylinder #3. Came in because it overheated (pinned the gage) lost power and started smoking. The customer let it cool down then nursed it home. He said that it had no power and was making a high pitched squealing sound. I used to brag that my dealer wasn't seeing many head gaskets and failed engines were a thing of the past... now I am getting HAMMERED! /forums/images/%%GRAEMLIN_URL%%/banghead.gif /forums/images/%%GRAEMLIN_URL%%/smhair.gif Then the truck proceeds to run away for about 15 seconds, so that made further diag a little risky in my opinion. I was just wondering what the hell happened and if there was anything else I should check other than turbo boost and fuel psi when I put the new long block in it. Eric, one of my teammates had one that ran away out in the parking lot while running some tests. We determined that the root cause was fuel dilution of the engine oil caused by an injector(s) This in turn damaged the turbo seals, and the same thing happened to the turbo, compressor wheel in the down pipe. This doesn't explain your burnt pistons but the runaway situation is similar. When the turbo was failing it was filling the intercooler with oil diluted fuel which the engine began sucking out and took off. The pictures from that failure are in the photographs section in Engine Failure One. Quote Link to comment Share on other sites More sharing options...
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