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Thread Title:

1999 12.7 piston issues

Created On Tuesday March 13, 2012 14:28

660hpseries60

Posts: 5
Joined: Mar 2012

Tuesday March 13, 2012 14:28

Thanks first of all to all that help out! I have a 1999 12.7 series 60, in oct of 2011 it lost a head gasket, this year, it developed the famous timing gear cover leak/crack. In the process of getting the back cover fixed, the mechanic used the bottom timing mark...thinking it was the tdc mark. He got it all together, attempted to start it, and it wouldn't fire start. He took it all back apart, and when, after pulling the #1 injector to verify tdc...he found a elephants foot broke, and a bent valve. so...off comes the head again. got the truck back...felt like it had a miss in it, 10 mi later...there is a growl coming from inside the timing cover, took front half of cover apart, crank gear was ground up, bull gear had a tooth missing. replaced those 2 gears. after fighting oil leaks again, finally got the truck back...drove it 100 mi, and it sounds like a piston let go. My ? for the 60 series guys, is...if my motor was timed wrong, at the bdc mark, would there #1- be piston to valve clearance issues...meaning did they touch? #2- when and if they touched...could that have taken the piston out? #3- would it have ruined the gears? the motor only has 310000 on the inframe, and 1.35mil on the block. Any help, or pages posted from a detroit book would be helpful...cause i think the attemped starting of the engin could have damaged the piston, and the gears. Also after the gears got replaced...i noticed it did not have the response, and would make a thumping sound under load...and when i boost to 27psi, it sounds like all boost is rushing out somewhere, and yes, it passed the air coolr leak down. all boots are new, with new clamps. Thank you for you time!

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theakerstwo

Posts: 149
Joined: Jan 2009

Tuesday March 13, 2012 17:25

I hate to be the one to tell you this but if the man did not know how to time the crank gear to the bull gear he would not know how to set the very need gear lash in the gears. All need .002 .oo9 in them and he may not know that you have to use a line up tool when installing the housing to the block. Also if he did not pull and repair ever valve then you have to pull head again. There will be in most cases valves on all six cylinder hit the pistons when 180 degrees out.Also to in so cases even tho the piston are steel top they can damage a pston or bend a rod.Then i who not think he would know how to check the cam timing after he got it together and other than that sounds like your screwed.It happens when you get some one that has talked to a freind that has read a book on engine rebuilding..

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660hpseries60

Posts: 5
Joined: Mar 2012

Tuesday March 13, 2012 19:04
Thanks! They do know what they are doing...it just happens to be that they read the timing mark wrong on the crank gear. They are trusted by PDI to do stuff, so that is not an issue with me. I'm not trying to badger you, just so you know. Was just looking for a second opinion...since i couldn't get ahold of the service manager at Detroit Diesel.

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660hpseries60

Posts: 5
Joined: Mar 2012

Tuesday March 13, 2012 19:21

Also from what we could tell...it looked like the oil pump gear is what ruined the crank gear, because what was damaged was the same thickness as that gear. I also never had a loss of oil pressure, 52psi at highway speeds, 38 at idle after oil temps running at 180 degrees. The bull gear lost half a tooth, and started to work on other teeth...meaning chew them up. my main question is did having the timing off 180 cause the pistons to hit the valves, and did it cause the gears to go out, if the valves hit and stuff turning inside cause gear to get chewed up, and did the contact hurt the pistons?

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westcoast

Posts: 982
Joined: Dec 2008

Tuesday March 13, 2012 22:43
As theakerstwo said they did,nt time it correctly and worse still they didn,t check oil pump to crankgear clearance Regards David ------------------------- detroit

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theakerstwo

Posts: 149
Joined: Jan 2009

Wednesday March 14, 2012 03:06
Yes they did not check the back lash and i have seen a few engines were you had to shim the oil pump to get the backlash. There is oil pump shims for that. No on the valves hitting the pistons causing the gears to go bad. And yes the crank to cam timing being off 180 degress is what bent the valves.t can also bend some rockers ams.

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660hpseries60

Posts: 5
Joined: Mar 2012

Wednesday March 14, 2012 07:17

Ok. Thank you very much. I just came from the shop, and the new crank gear that was put on, is chewed up again, and looking from the bottom side the, the liners are scuffed. They are pulling the head to see if there is a piston broke. At first the guy working on it this time...said the rings can make it knock like that, i told him that is not true, that noise comes from a broken piston...dealt with enough of those with people building small block chevy's using hyperutetic piston...and running them hard when cold. A broken ring will only cause blow by, and might score the cyl wall. So we will see what we find out today...if the pistons have marks on them. Thanks again.

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JoeZ

Posts: 938
Joined: Dec 2008

Wednesday March 14, 2012 10:20

I hate to be the bearer of bad news.....but that engine needs to be stripped down and completely gone through. Don't for one fraction of a second be led to believe all that ground up metal didn't damage all your bearings, oil pump and maybe much more. It may run for a short time, but it will come back and haunt you. Bent valves, broken pistons, bent connecting rods......what a mess. Everything needs to be checked at this point. Bottom line......find a better shop or at least a shop more familiar with your engine.

-------------------------
One of the last 2 Stroke mechanics left.
44 years in the business and worked on everything from 53 series to 149 series. Winding it down now...time to move on.

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theakerstwo

Posts: 149
Joined: Jan 2009

Wednesday March 14, 2012 15:49

And i always replace the oil cooler because you can get the cutting out and they just release slowly onto the new brgs. They may tell you the oil filter will get the cuttings before the oil cooler or brgs see them but that in most cases is not so. Mant times the filter will load up with coolant or cuttings then the by/pass valve will let oil by/pass the oil filter to keep it lubed.I have seen it many times with untrained help.I have worked in the dealership many years so i have seen most of what goes on. In then end they will make you believe its your fault for it not making it.glenn

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JoeZ

Posts: 938
Joined: Dec 2008

Wednesday March 14, 2012 16:32

Absolutely.....the oil cooler gets forgotten too many times...along with the turbo....I always insist on doing the cooler and if an engine has scattered, I won't do it unless the block gets boiled out and cooler replaced.....good advice!

-------------------------
One of the last 2 Stroke mechanics left.
44 years in the business and worked on everything from 53 series to 149 series. Winding it down now...time to move on.

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660hpseries60

Posts: 5
Joined: Mar 2012

Wednesday March 14, 2012 20:01
Thanks to all!! found that none of the exhaust valves were bent, 4 intakes were. pull the #3 and 4 pistons, because that is where the sound was located at. The rings look good, no carbon build up. We are deciding what to do...the deck is pitted really bad. thinking about dropping another motor in it.

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theakerstwo

Posts: 149
Joined: Jan 2009

Thursday March 15, 2012 19:29

<< Thanks to all!! found that none of the exhaust valves were bent, 4 intakes were. pull the #3 and 4 pistons, because that is where the sound was located at. The rings look good, no carbon build up. We are deciding what to do...the deck is pitted really bad. thinking about dropping another motor in it. >>

That will sure help the guys out that messed it up i guess.
I was involved at the dealer with a fleet of trucks that had problems with new engine maybe in 01 or 02. Arrow trucking here had about 80 trucks to drop pistons on new trucks. The pistons were debonding and in some case blow the side of the block out.The piston would come apart and drop a valve then the broken parts some times would go down between the crank and block and blow the side out around the ecm. Abot 30 of them had tro have complete engine installed and rest was done here with the hopes of DD doing them on warranty and i dont know if DD helped or not.DD said it was a maintence problem. But the drivers would drive them as far as they would go grinding metal up as they go. If one came in with just junks of metal in the pan i did not worry but those that had fine cutting and coolant in the oil was bad. What happens the coolnt gets in the filter and plugs it and the filter by/pass lets dirt and metal go thru the lub system but hi up bean counters can not under stand this.The first one we put to gether that way oked by the coustomer did not live more tha a couple days and they still ask why the new brgs went bad. i saw some funnt stuff with them untill DD come out and adviced the customer on them. glenn

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JoeZ

Posts: 938
Joined: Dec 2008

Thursday March 15, 2012 20:21

<< Thanks to all!! found that none of the exhaust valves were bent, 4 intakes were. pull the #3 and 4 pistons, because that is where the sound was located at. The rings look good, no carbon build up. We are deciding what to do...the deck is pitted really bad. thinking about dropping another motor in it. >>

When I was 17, I was moonlighting as a mechanic at my uncles house after school and on weekends. He wasn't a mechanic....he made candy. A friend of my uncle had a 1956 Ford towed to in. The engine had just been rebuilt but was getting water in the oil. The guy that had rebuilt it worked fulll time and didn't have time to look at it. He said maybe a head gasket was leaking. As I was pulling off the heads, I noticed one head bolt was tight but sticking up. So there had to be the problem. Not so. When I pulled it down I found out he mixed up a head bolt and put one too long for the hole. The block was cracked. It should have been a give away since the owner said they had to tow it down the road to get the engine to turn over and start. Nevertheless, the guy that did the engine said it was junk anyway and the owner was at fault for having him rebuilt a junk engine.
So the message is that's it is your fault for having them repair an engine with pitting on the deck.....so when all else fails, throw the engine away and put one in from a truck bone yard.....let them take the easy way out. They can't fix it right so junk it. You have to know by now they are totally lost in this job. RUN!

-------------------------
One of the last 2 Stroke mechanics left.
44 years in the business and worked on everything from 53 series to 149 series. Winding it down now...time to move on.

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