Are LLY better than LB7

[marktara]

Looking into getting a new durmax and was trying to find out if the new LL7 is better than the old version, because there are a few of the old ones still sitting on dealers lots here?

[DMAX4LIFE]

I've driven both and power wise the LLY definitely has the upper hand. I also think that the new design of injectors/fuel rails will make for much cheaper repairs if they are needed. So if it were me, it'd take one h**l of a deal to make me buy an LB7 over an LLY.

[Chevy Ryan]

I would definitely take the LLY. Just being able to remove the injectors without taking the valve covers off makes it worth the extra cost. The factory high idle, faster glow plugs and added power are all icing on the cake! I was apprehensive about EGR at first, but when I found out that the recycled exhaust goes staight into the engine and not through the intercooler, that made me feel better.

[gdib]

How about trading in a 2003(LL7) for a new 2004(LLY)? With the current rebates its an interesting proposition (about $6000+). You would pick up the benefits of the newer engine, with a new truck. My main concern would be the EGR valve as well as the addition of a catalytic converter. Any suggestions/comments would be apprecited

[mps007]

Mines Coming this week smile.gif !!!
Having trouble finding it in NJ though .. Came off the train but no none knows where it went ....

But with incentives , 0% & trade - My payment will drop 100/ month

[Husker Fan]

Not so fast.

Although I

[mdadgar]

There are plenty of LB7 trucks with EGR running around with more than 50K miles on them. EGR started on '02 Califonia-delivery vehicles.

Anyone got an EGR-related problem? Anyone?

I didn't think so.

Lots of people here talk about how evil EGR is. No one (and I mean NO ONE) can give good reasons WHY its evil.

- Mark, '02 CA-emissions truck, still waiting for reasons

[DmaxMaverick]

The gunky mess that builds up in the intake is an evil misconception. The EGR does not cause it, entirely.

The mess comes from the CDR. Oil vapor coats the intake, and the EGR adds hot exhaust gasses laced with soot and other particulates. The combination of them makes up the goo.

The use of a properly routed and cooled EGR and an efficient CDR/PCV will prevent this from happening. On a couple of the older Pickup Diesels I've had were modified with external crankcase vents. The intakes always stayed clean, except for the powdery deposits of the soot. Later mod's left the engines with the EGR disabled, so that cured it completely.

[gdib]

My 1998 6.5 had a Catalytic converter and I was told this was a "soot" trap. When I bought the 2003 duramax, I was glad to see it didn't have one. I believe the 2004's will have this with the EGR. Will the catalytic still act as a soot trap in the duramax?

[Jorday]

My 2004 doesn't have a converter, but it's an LB7

[Chevy Ryan]

I was not implying that the LLY would be immune from deposits in the intake system. My point was that at least the intercooler would not have exhaust going through it, leaving one less place for soot build-up. Yes, if I had a choice, I would prefer no EGR, but every L56 engine from 1994 to 1998 had EGR. And in my time spent working in the service department at a GM dealer, I never saw an L56 with an EGR-related problem. Did I see soot in the intake? Yes. But enough to cause restriction or problems? No. Not flaming here, just clarifying the point in my first post.

[Chevy Ryan]

gdib,

Yes, the LLY-equipped trucks have a catalytic converter. It's designed to reduce particulate matter (PM). PM is what you see as smoke. EGR was added to cool the combustion temperature inside the cylinder, thus reducing oxides of nitrogen. But when you cool the combustion in a diesel, PM goes up. This is why they added the catalytic.

[oyazi]

Our thinking is shaped by our experiences ~ when it comes to EGRs & CATs, we fall back on gasser experiences. I don't feel handicapped w/my EGR equipt LB7. Given the choice ~ I'd go w/the newer eng.

[Tractorhauler]

Chevy Ryan,

Can you tell me why some DMax truck smoke like a tractor at a pulling show and why some "like mine" have never issued out enough smoke to make a puff?
I have 49 K and have hauled long distances with heavy tow and done short driving as well and never have seen smoke.
The other day a guy was turning his Dmax in front of me and I could barely see his pickup box from the smoke.

[Chevy Ryan]

Tractor hauler,

Dirty air filter can cause excess smoke (too much fuel and not enough air). Over-fueling causes too much smoke (how much they've turned up the fuel flow through power modifications). Bad injectors can also cause excess smoke. We saw quite a few Duramax trucks that would blow lots of blue smoke at idle, even after reaching operating temp. Plug in the Tech II, and there were almost always one or more bad injectors. If your truck doesn't smoke, I'd be happy with that. Just remember that smoke is unburned fuel and the power that could have been made is being wasted going out your exhaust.

[Tractorhauler]

By the way Ryan, this was very black smoke that I saw comin out of this baby.....
Could that be anything besides fuel; ie. rings etc.

[Tractorhauler]

By the way Ryan, this was very black smoke that I saw comin out of this baby.....
Could that be anything besides fuel; ie. rings etc.

[OC_DMAX]

Probably had a modified vehicle. Reprogrammed ECM and/or Juice box added to truck. Talk about black smoke, just go to one of these dyno events that are held with diesel trucks.

[Chevy Ryan]

Ditto what OC_DMAX said.