ISX DOHC Needs new head.

[Scottj96]

I have an 07 kw w900 with the DOHC ISX and we have determined that the head is cracked as I am getting fuel in the oil. I see aftermarket heads and oem heads. I can get an aftermarket {garbage head} for $3500 or I can get an oem for like $8000. I don’t really want to put a head that I know will eventually crack back on but I don’t want to put junk on either. Looking for pros and cons of both please

[mikkhh]

2007. Is it a clean truck? No rust? Has plenty of life left in it? Has the crank dampener been replaced? If not it has to be replaced. Is the ecm new or cummins reman? If not then you have to keep in mind that it can fail rather sooner than later. Most likely if you have it fixed by somebody it will cost you 30-50k just to get the engine part properly sorted. What about gearbox? Axles? Maybe it makes sense to buy newer better shape truck and sell your old one since people are willing to pay way more for those junk machines then they are rationally worth. Pull the programming and have it reviewed first . Fuel pumps could not leak fuel in oil? Maybe injectors are so bad and dropping fuel into engine ? Maybe programming is bad and ecm just dumps fuel into engine after the combustion event to either regen dpf or warm it up? Is the turbo still stock or aomebody has butchered with vgt removal?

Aftermarket heads are junk. Since head has to be removed it is absolutely mandatory to cut the liner seats and raise protursion to 0.14" and while you are there it makes sense to compeltely overhaul engine and to avoid problems in the long run and have the repairs last a long time to come. Only use genuine parts on engine internals. Aftermarket parts just do not last nowhere near as long as the genuine parts. Tolerances are way across the board too so you have to be really experienced to use them properly and sometimes for example engine bearings case you have to buy many sets of aftermarket liners to get a good matching size set together. That takes experience and time and extra sets of parts, extra delays, extra costs involved. If you factor in the cost of proper install and extra parts needed the initial cost can be even higher. BUT longevity wise those bearings may fail prematurely due to material peeling off or any other issues, there is just no match to genuine parts sadly.

If you use cheap internal parts and let's say you happen to spin a main bearing then you end up with scrap block, scrap crankshaft, scrap oilpump. Aftermarket heads wise tolerances are all over the place and sometimes injectors may sit lower or higher commpared to cylinder head face level. That can cause lots of issues with engine operarion and proper running that is very hard and time consuming to pin point. What is more those aftermarket heads usually have lots of casting defects and sand still left in them. That sand can wreak havoc in the wrong places. I will try to find visual examples of new junk aftermarket parts.

[Rawze]

(12-07-2025 )Scottj96 Wrote:  I have an 07 kw w900 with the DOHC ISX and we have determined that the head is cracked as I am getting fuel in the oil. I see aftermarket heads and oem heads. I can get an aftermarket {garbage head} for $3500 or I can get an oem for like $8000. I don’t really want to put a head that I know will eventually crack back on but I don’t want to put junk on either. Looking for pros and cons of both please

The OEM head should not be cracking prematurely unless your severely abusing your engine, not even with heavy haul applications. Most of the time its caused by a bad, engine killing delete program.

Also, Every single after-garbage branded 'stage whatever trash crap they call them' head that I have ever seen anyone use has not lasted more than about 2 years max or so at a time. - Cheaper = a whole lot of wasted moneys and regret.

So .. the real concern is not 'using garbage cheap parts because they keep failing' .. but ... 'how to get your engine to stop destroying itself in the first place'.

That starts with having any (delete) programming copied out and reviewed to ensure its not killing the engine internally, and causing all those headaches. And otherwise, also looking into WHY it would destroy/crack the head prematurely to begin with, preventing the base issues, instead of suffering with them.

If it has a de-mandate program in it, that is the first step... copy it out and e-mail it to me for a review. For all anyone knows, the injection timing might be whacked into oblivion, and the engine stuck in full-on piston scraping mode all the time.

the next step is to build it right... to which almost no one does any more.. even the shops that claim they are really good.. are completely clueless!. Here is how it should be done...
info: https://rawze.com/forums/showthread.php?...6#pid70606
... and good luck finding anyone these days willing to do all that extra stuffs not in the manuals ... because shops are too damn arrogant or lazy to do anything right any more.

Anything less, and your just pi$$ing moneys out the cab of the truck.

[Scottj96]

Thank you sir. I am going to get an oem head from Cummins. I will see if my mechanic knows how to pull the info from the ecm and get it sent to you ASAP. I appreciate your help.

[hhow55]

Could also be an issue with the Integrated Fuel System Module...........If you go to quickserve.cummins.com you can read all about it. If a head is needed definitely go with OEM. How many miles since last engine overhaul?