No announcement yet.

R2.8 problems

  • Filter
  • Time
  • Show
Clear All
new posts

  • R2.8 problems

    Hello everyone. This is my 1st post so please forgive me if I've overlooked this elsewhere on the forum. I found some unflattering remarks regarding the R2.8 and I'm just trying to do my due diligence and find out more information. There were complaints that the ISF 2.8 has a very poor reputation in China and Australia. Problems include excessive cylinder wall wear, rod bearing problems, water making it's way into the cylinders, easy overheating.... some unsavory stuff. I already own a 5.9L dodge and love it. In fact, where I live, you have to genuflect when someone says "Cummins". So I'm not trying to start any sheet. I just want to be sure that if I sink 8K$ + into a new engine that it'll last. I'd appreciate any thoughts you Cummins veterans might have. Thanks.

  • #2
    I've read some similar stuff before I ordered the R2.8 Cummins. For diesels and especially in China there's so many things you can do with a computer and you may also have some non-Cummins stuff out there. The 2.8 Cummins is not a the classic inline 6, which is a much more heavy duty engine that can be found in heavy equipment and obviously heavy trucks. R2.8 is meant to be put in vehicles from what I can tell, so it's just not going to last like all those B-series lasted. I have the 5.9 Cummins in my truck and I will probably be getting another 5.9 Cummins truck for the wife. I wanted a small 4x4 type vehicle and the diesel option is obviously very very poor in the US. I almost got a Duramax Colorado ZR2, but for the price and size and some other reasons, really wanted my TJ to be powered the way it was meant to be powered. Out of the options out there, for a well mannered daily driver the R2.8 has A LOT going for it. And for one it doesn't require DEF and frequent trips to the dealer to fix the EPA's overreach and poor thought processes.

    I've heard mixed reviews on what the bottom ends can handle for these engines once you get into tuning. IMO if the OEM specs meet your needs and intended purpose then I personally wouldn't push over 10% increase in power, but that's just a rule of thumb kind of thing with no insight. I will probably be getting mine tuned, but mainly as an attempt to ensure my engine is tuned for what's best and not by what the central bureaucracy dictates.

    Out of the diesels out there and I don't know your application at this time, I think the TDI is a bit under the displacement I'd prefer for a 4x4 vehicle. Remember before your turbo kicks in I believe you're relying on displacement. A 5.9 is still pretty mean at 1k RPMs, but the R2.8 is not the same under 1,500 RPMs. It's got plenty of grunt off-road, but on-road, especially towing, I have to remember to keep my RPMs up higher than I'm used to.

    4BT is very big and very expensive nowadays. The other Cummins floating around are probably fine, but I look for that stuff and rarely find one for a reasonable price (haven't looked in awhile either). The Kubotas are kind of intriguing, but I've seen too few completed to trust them yet. 6BTs are even more everything than the 4BTs. Mercedes diesels are either underpowered or too complex for me to tackle. The new ED 3.0L are so expensive and I'd guess complicated.

    As far as gas engines, well it would be hard to go back personally for on road/off road stuff to gas. I think they suck and once you're used to low end torque, hell I'd rather wait for EV than take a big step backward. If you're racing then that's a completely different story.


    • #3
      I don’t have but a few thousand miles on mine maybe. But it’s been nothing but positive except for technical services. Note I said technical service not customer support. I understand there are some minor differences between the ISF engines you are hearing about in Asia and the domestic R2.8. Though it does appear the R2.8 is made in Asia. Anyways, wish I had 50k+ Miles on mine to give you better advice. But so far so good for me. Maybe when I finally find the right technical person to talk to I will be 100% satisfied.


      • #4
        Any body having problems with their r2.8 putting out too much oil through their pcv valve on the valve cover back into the intake. Installed an oil catch can and it filled up already with oil. Can’t seem to find the technical support number to call for help


        • #5
          Do you have a local Cummins dealer? In my experience they won't know that much about the R2.8, but maybe they do work on a lot of diesels, so maybe they'll know.

          It seems like someone else had a similar issue on here. Mine does not seem to have excessive oil come from my pcv valve, but there's definitely some. I would imagine that's due to the positive pressure inside this engine that is not the norm for most diesel engines I've ever seen.

          R2.8 Samurai had some issues in his. You might want to get on this one pretty fast with Cummins. He mentioned some experiences he had in Blowby through breather post he started.