Duramax Diesel Common Problems - Blown Head Gaskets, Bad Fuel Injectors & More

so here we have a 2003 GMC sier 2500 with a 6.6 L lb7 Duramax in [Music] it so I've been asked a bunch of times what do I think of the jur max now there's different styles of the jur Max uh the one that's in the shop right now is an lb7 which is really the first generation of gerax and it had a few common problems one being the injectors and number two being the head gaskets now as far as reliability and it comes down to maintenance again it always does I I do think that they're a good engine but I don't prefer them because when they break it does get expensive and this video will show you exactly why um the Jour Maxes have the exhaust running down the back passenger uh head and the exhaust is extremely close to the head and generally that's where the head gasket goes just because of the excessive heat buildup there this truck had just about everything wrong with it and it's not anybody's particular fault story from the beginning is he bought it with a larger fuel tank installed so 200 lit tank I don't know what that is in gallons but whoever installed the fuel tank didn't remove one of the bungs off of the fuel lines basically cut that little plastic line and and that little circle of plastic got jammed in a line somewhere and was restricting fuel flow truck wasn't running right uh it originally came out of Alberta made its way to Ontario which is kind of like driving from California to New York it's a long trip and as soon as he would hit over 100 km an hour the truck would would start to bog and kick and buck and start for fuel brought it to a shop who misdiagnosed it they replaced the injectors um unnecessarily and then sent them on his way again it's it was fine for a little while and then it started doing it again um probably because that bung moved into a different spot brought it to another shop who uh diagnosed it as the injection pump replaced the injection pump uh still didn't fix the problem then put a an auxiliary fuel tank on it and figured out that it was not the engine itself it was the delivery system so they in turn found the bung in the line cleaned it out on his way he goes but that did cost quite a bit between injectors and fuel pump and whatever else it's got a tuner on it and it is very impressive with the tuner on it you're able to make tons of power in it but think of it as buying a wheelbarrow that has the recommendation of 10 psi in the tire you can carry 100 lb in that wheelbarrow well if you figure out that you can add 30 lb to that tire now you can put 300 lb in the wheelbarrow yeah you can get away with it for a while but that wheelbarrow is going to break a lot quicker than if you just left it as recommended and that's what a tuner does in this scenario it really stress the engine it did not have studs put in it it was still the regular bolts with the head gaskets being prone to uh braking it it is just a ticking Time Bomb now tuners do if you if you behave with a tuner you can put an economy tun tune on it and you can actually increase your mileage now I made a video on is a tuner worth it I'm saying it as a mechanics point of view because when I got these heads machined uh The Machinist looks at me and says is there a tuner on it I have to say yes there is he says no warranty on any of the work want it decreases your resale value I wouldn't recommend buying somebody else's truck that has a tuner on it because you don't know what they've actually done to it it does have a memory you can check that but is it the original tuner you never no now this particular engine when we tore it down you can just replace the head gaskets if you're in your own garage I don't replace any head gasket without sending the head out to get checked to make sure that it's level and pled um and the reason for that is I've seen too many returns on head head jobs where um the head is Warped or the block is damaged and replacing the head gaskets is just a temporary fix now germax was first of its kind with common rail injection and um aluminum heads now they generally don't have a problem with the aluminum heads but I do believe that a tuner will stress the heads more than uh no tuner and I say that because when these heads were sent out they were out they were warped about 14 thou you can machine about four or five thou off the Duramax heads but uh without getting into any major issues but any more than that you risk the the heads and the valves actually coming down closer to the Pistons and you risk the valves hitting the Pistons so at 14th th all the valves had to be uh ground down too the seats had to be ground so the valves are farther in the head so that the valves had zero risk of hitting the Pistons once you get the wiring out of the way it's a lot less daunting um basically it's just an engine we'll get rid of the front covers here get rid of the turbo and then we can start looking at the fuel management system and then uh get ready to pull the valve covers off it's just that easy so we got the valve cover off and uh first oh there's one injector doesn't look that great and there's the other injector that looks terrible probably wondering why it's running like a dog and then there's another injector I already wiped that looking at it thinking what the hell is that but just moisture P maintenance see all the gunk it doesn't work so well on the injectors guys you got to change your fuel filters this number one cheapest thing to save a giant headache now these injectors were dirty I sent them out to get tested put in a machine that Bosch actually designed to test their own Bosch injectors and what it does is check for internal leaks spray pattern leak down what it doesn't see is the external leak and that's up to the tester to look visually and see see whether the injectors are leaking or not all eight of these injectors even though they only had about 40,000 km on it were leaking in between the electric solenoid and the injector itself and that's because somebody I I would think um while they were diagnosing the truck not running properly disconnected the fuel pressure uh line sensor and made the injectors go to full pressure which is the 22,000 PSI and that that was too much for those injectors and they started leaking um still what a ran find but every minute of that truck running would each injector would would leak two drops of diesel fuel into the engine oil and pretty well got her tore down now you can just leave the turbo alone and just take the uh exhaust manifolds off at the back and then off at the side there uh this last head bolt here you can't uh really get out that nice so you can just zip tie it to uh you can see that there just zip tie it to a valve spring keep it up and then it'll be easy to take out and then uh up and out she comes so you leave your manifolds on they'll fit they'll fit on there um can't really get it the bolt of the back with with the turbo in the way and this front bracket you just tilt forward it don't unhook any power steering lines and then your steering shaft just disconnect it right there and pull lift it up on it drop it down you got lots of room so yeah here we go you see the coolant number four four at the back there number eight whatever that is and uh definitely the head gask in the back corner you can see where the gas get split apart too so we'll get the heads sent out get them checked planed and then we can start putting stuff back together again so very just that simple here we go so the biggest thing when you're working on gerax is take your time taking it apart and take some pictures while you're taking it AP you got your phone take it out take some pictures take some video walk around where does this bracket go where did that ground come from I did a time lapse more or less just to show you guys if you guys are kind of stuck wondering where something goes or where something fit or exactly how I did it I hope this video really helps you out go online get some torque specs you know it's a good write up when there's uh 150 different torque specs for everything that you unbolt from that engine and remember that everything has a memory so don't disturb it more than you have to take it off lay it to the side and take your time when you're taking it apart to label a few things if they're long wires that don't really go in a group just Mark those so you remember okay that came off the intake okay that went on the glow plugs rooted around the front right passenger head things like that will really help you I can't really make an entire video on start to finish because it will be a 20-hour job there is a lot involved to this but take your time if you're stuck in a certain spot just pause the time lapse and hopefully that will help you guys out here we [Music] go [Music] a so bad the cooling system just pull this little plug out of the top of the thermostat housing and fill your Reservoir until the coolant comes out if it doesn't then just take a little bit of air pressure in a rag don't KN much a couple pounds just to push it through and uh until you start seeing coolant come out of there to bleed the fuel system this is a little pump on the top of the filter housing here and then there's a little plastic uh screw there 13 mil I believe crack that loose and then just pump away until you see Fuel and then keep pumping until it's hard crank it for about 5 10 seconds then Pump It Again crank it another 5 10 seconds it should start after that so here we [Music] go so would I buy a jamax yeah I think so I think it would be really cool to uh if the budgets ever get big enough that we can build some really cool builds I'd love to put a jamax in an old truck or something rat rot or even an old muscle car I'm I'm up for that um don't get deterred by this video from buying one just know that when things break they do get expensive I'll still be a 12 valve cumin guy just because of the Simplicity and the ease of working on it it doesn't get any better than keeping it simple and mechanical so this is first generation jur Max and it's got enough of its own issues if you're getting into emission stuff you're into a whole other can of worms you're looking into afterburners DPF egr's all more things that can hurt your wallet uh I would recommend a jamax uh know what you're getting into do your homework when you are buying one but uh I'm actually looking forward to uh being able to install something like this into something cool so stick around hopefully we get another jamax in here to convert into something but for that job it's generally pretty simple engine once you get over the actual fear of getting into it because it looks so daunting with all the crap under the hood but uh good engine tunable we're going to have some fun with it eventually I'm sure um so stick around hopefully we can throw it a dirty Max into something old and dirty here we go hey hey thanks for watching don't forget to like And subscribe cuz you never know what you're going to see next week on De boss garage if you like what you see there's a lot of stuff happening to help support the channel and remember if you're not filthy you're not rich

Channel: DEBOSS GARAGE

Views: 502,872

Keywords: duramax, duramax common problems, 6.6 duramax lb7, duramax v8 engine, lb7, duramax 6.6, gmc, chevy, duramax 6.6l turbo diesel v8 engine, duramax 6.6 problems, duramax 6.6 engine, head studs 6.6 duramax, head gasket duramax lb7, duramax head gasket replacement, duramax blown head gasket, duramax lbz injectors, replacing injectors duramax lbz, injectors test and replacement, fuel injectors testing, diesel injectors testing, injectors testing, coolant leak, duramax rebuild

Id: 97EKK_MM5Hs

Length: 12min 6sec (726 seconds)

Published: Sun Feb 12 2017