I have a GMC C6500 with a 3116 cat and have a chance to purchase a truck a couple years newer with a 3126. Is there much difference in power? Is the 31236 a better engine? How many miles till overhaul? My 3116 is slow on hills. How does it compare to a International DT 466?
I have a 3116 in a 953C Cat loader that is excellent,,,,, and I have a 3126B in a larger service truck that I have had some problems with, long story short- I will never own another 3126B......
What kind of problems have you had with it? I hear that they are a pretty expensive motor to work on.
The 3116 is mechanical, 6.6 liter, rated at 170hp and up. The 3126 is electronic, 7.3 liter (?) and starts at about 200hp, so the 3126 would compare a little closer to the DT 466. Judging mostly from what I've heard, this might be an engine family where "the devil you know is better than the devil you don't know".
Had to replace all injectors first at 50K miles. Then the problems started- had several high pressure oil lines blow, when one blows it pumps a lot of crankcase oil all over the engine and then shuts itself down due to low oil sensor. Then you call a tow truck or get your lowboy and get her back to the shop and figure out what oil line it is , after a hot powerwash to remove the oil mess. I have went 2- years now without a blowout, but have replaced many, if not all, high pressure lines too. Me or the Cat dealer, still do not know why or what caused the problems. One thing is for sure that 3126B engine does not like dirty engine oil, I change it every 2000 miles and everything seems to work better. And lastly, Yes, get your checkbook ready after a visit to the Cat shop.
Delmer, you hit the nail on the head on that.
The designation 3116 and 3126 refers to the liters-per-cylinder, ie 1.1 or 1.2 and 6 for 6 cylinder. There is also a 4 cylinder 3114. A 3124 was never made. Both 1.1 and 1.2 first came out with mechanical unit injector (MUI) fuel systems, although these are all known to Cat techs as 1.1s. For example the fitter walks up to the tool store and says "Hey. Get up off your lazy arse and give me the one point one setting gear" Later, the 3126 changed to a Hydraulic Electronic Unit Injector (HEUI) system. This is the one making a mess of JGBASH's truck when the oil line from HEUI pump to cylinder head fails. There were a few updates to this line and I've not seen one blown for quite a while now, although even the smallest Cat parts depots seem to keep a few on the shelf As far as I know, 3114 and 3116 were not produced with a HEUI system.
What kind of oil pressure should a 3116 carry?. Mine had 325K miles on it when I got it. When I bought it I didn't think that was a lot of miles for a diesel but an beginning to rethink that. It carries about 45 lbs going down the road at about 1900 rpm. When I come to a stop light at idle it drops back to about 10 to 15. I think this might be too low. Should I be thinking about another engine? Seems to run ok and does not use much oil.
I can't speak to the 3116, but I can to the 3126B: I have two of them: one in a dump, and another in a hauler. It is the 225 of diesel engines. Do right be her and she'll do right by you. It is a pre-emissions diesel workhorse. Won't win any land speed records, but it is a very dependable, tough engine. It is also low maintenance (as far as diesels go)...with the following caveat: as JB noted, keep the oil and filter clean. Let me repeat: keep the filter and oil clean. Everything from the injectors to the turbo relies on the oil, and the oil pressure. As far as going up a hill: assuming you're geared ok, know that most of these Cats are governed at 67-68 mph. Most of the issues I've read with these engines are people tinkering with the engine trying to get more HP out of it. That being said, I'm considering getting new exhaust for mine as it's shot from the exhaust pipe back. When/if I find a source, I will be replacing all from the manifold back to eek out some more oomph without the risk of harming the engine.
I have heard bad things about that family of engines, especially the 3116. However, I want ahead and bought an older Kodiak, with the 3116 engine. It had 327,000 on it when I purchased it, and to be honest, I was pretty worried about how it would do for me. That engine was very strong. I used the truck to pull a gooseneck loaded with firewood, through hilly country. I was grossing around 35,000, with truck, trailer, and load. Never felt truck was underpowered, but, it had a 10 speed trans., so that helped a lot. I ran the truck hard for 2 years and never had any trouble. Changed oil every 4000 miles. I have since bought a flatbed dump with the 3116, and am currently looking at a grapple/dump with the 3116 engine. I think the 3116/3126 engines are fine, but possible need better/more frequent routine service than a DT466. Heck, you can change the oil and filter in a DT466 once every 2 or 3 years, and never worry about it. My preference would be the DT466, as it is bulletproof. Trucks with that engine are just to expensive for me, as a rule of thumb.
I have heard that after around 2003 International had some engine problems too, ( cyl o rings I think) and a lot of other truck complaints. I like the way the cab is made and the looks of the GMC. I just hear a lot of horror stories about the engine. I have heard some going out with less than 100k and others lasting a long time 3or 400 k miles. (What are your oil pressure readings)?
As I recall, both of the 3116 engined trucks have oil pressure at around 55-60lbs when running down the road. At idle, they are at around 25lbs. About those international DT engine problems: I drive school bus part time. We have 20, of the 2004/5 International buses with the DT466 or DT360? engines. Our buses take a beating and get almost no preventive maint. We have had about 12 of them lose engines in the last 2 years. All had only 120,000 - 136,000 miles when the engines failed. Both types of engines had the same problem, blown head gaskets. QUOTE=John White;457036]I have heard that after around 2003 International had some engine problems too, ( cyl o rings I think) and a lot of other truck complaints. I like the way the cab is made and the looks of the GMC. I just hear a lot of horror stories about the engine. I have heard some going out with less than 100k and others lasting a long time 3or 400 k miles. (What are your oil pressure readings)?[/QUOTE]
superb knowledge on cat engines what you said is 100 percent correct Mr.mark
Cmark, What was the idea / advantage supposed to be behind the HEUI system over the mechanical one? I even replaced the Cat update line kit after it was replaced. But the second time around I had a high pressure hose made up and it has held so far, but we continually keep a close eye on that engine for any possible rubbed lines, cracked lines or any thing else that catches your eye. The engine has about 100K miles now and still runs good and starts and beside the oil leak issues it has been OK. Catback, You are correct, clean oil is a must for the 3126B or it will punish you when you need it the most...
I really don't know Cat's motovation for moving to the HEUI system, but you can be pretty sure it comes down to one or more of the holy trinity of cost/fuel economy/emissions. Some engines can be upgraded to a steel line in place of the hose. Is this the kit you fitted? If so, there's a fairly detailed fitting instruction with torque settings etc to prevent early failure. If not, post your serial number and I or one of the other good people with access to SIS will let you know the relevant part numbers.
I guess I need to throw in my disagreement here: The 3116 is not that bad maybe but weak and it takes a special tool to set the injectors that is only good for that engine and is getting scarce. The HEUI 3126 and C7 can be a nightmare. They are known for throwing metal at the injectors that cannot be cleaned out but some have developed a solution. Or just tear the whole top of the engine apart and clean it all when it happens. They also used to blow up a lot from the lower end because you have to rev the snot out of them to make them have any power and overrev them just once such as cresting a hill and they go pop. There are other problems also. They are a cheap, small engine for cheap, small trucks IMO and not very good for even that. Also, I know there were some late 3116s that had HEUI, and some industrial 3126s that were mechanical. There is always an exception somewhere
Yes, It is that line you refer to. I put the updated steel line on and after a couple months it blew apart. Went and got a second one and in a month or so it blew. That's when I decided I would put the hose on and now a good 2-years have passed with no problems. But just yesterday I looked it over and have a leak starting around the pump area. Seems to be small at present and oily so I could not tell exactly what it is, except it is not the hose. Thanks Cmark, I will get the SN#
I'd say if the hose is working for you, stick with it.
Exactly where are the HEUI lines located at. I talked to a fellow on the phone who has a C6500 for sale. He said he drove it 200 miles home and has a small oil leak. The owner he bought it off of said the HEUI line was leaking. If I get it I have to drive it about 450 miles home to get it in my shop. I don't want it blowing up on the road. Is this just a line that could be tightened to get me home? What is involved in replacing the line? Is this the steel lines on the left side of the engine?
Fair enough, but what is a better engine in that age and class? These engines are comparable with the cummins 5.9 and DT466, which have had their own issues. And I'd rather have any of the sixes over any of the competing V-8s any day. Regarding what kind of oil pressure they should run, if it's in a GM product I'd test it with a real gauge before doing anything else. The pressure gauge in the dash is better than an idiot light, but it's more of a "notional" measurement than a precise reading, kind of like a lot of fuel gauges or temp gauges.
There's two oil lines going to the HEUI pump. The low pressure one goes from the oil gallery on the side of the block to the HEUI pump. The high pressure line goes from the the HEUI pump to the cylinder head.
I have cat 3126 with unit injector powering 950 g, chronic issue with that is injector sleeve cracking,cylinder bore cracks(which has no sleeves)etc, later the 950g series 2 came up with HEUI where all such problems were eliminated.
So how do 3176 and 3196 fit in ? Are they both all HEUI ? Does it follow the same rules 1.7 ? per cylinder and 1.9 L per cylinder ? What were the differences between 3126 to 3176 and then 3176 to 3196 ? If the 3126 became a C7 what happened to 3176 and 3196 - C11? Thanks
3176 and 3196 are not HEUI but they MEUI ( mechanicaly operated unit injectors)