munyanb

Does the 4.0 have enough of a following to have an affordable aftermarket 4.0 made that will bolt up and run on the electronics, but be designed better to give better power? BMW has some straight 6's that scream as well as Mercedes, and they aren't to far off from the 4.0 design, no engine is really. It's old 125 year old technology no matter how you look at it.

munyanb

The head could easily be made into an overhead cam design for one, still using the same bottom end. The bottom ends are so crude the could be worked a little also.

dave1123

Jeep engineers have already decided the 4.0 is too heavy and too long and tall to fit modern body designs, so have replaced it with the 3.7 V6. Also, the 6.4 Hemi fits the WJ platform without frame mods, so why keep the 4.0? It's not a high reving short stroke engine and will never produce the power of better designs.

I, personally, am sad to see it go.

munyanb

Don't you think a 6.4 hemi will be un manageable in a jeep? The 4.0 is so easy to manage and has enough power for anything it encounters. It would be great in a 2 wheel drive street race jeep. The hemi I mean. So any input on why this valve cover gasket will not seal? I have a new looking gasket, it almost seems like the grommets are to thick to let the valve cover seat on the gasket. What should they be torqued to anyway? And how common is the coil rail failure? I see they sell in the thousands on ebay.

munyanb

Well I have bad news on the jeep, haven't had much time lately to mess with it, but to bring you up to date, the engine ran without the knock, but still had a miss. I bought a new coil pack, and now the engine will not start, it gets stopped cold whenever it reaches the previous non firing cylinder. I had the valve cover off, and thought for sure I saw every rocker moving, but apparently one exhaust valve is either clogged or not opening. It backfires violently through the intake, enough to blow every vacuum hose off. black smoke also. I have no more time to mess with it, trying to sell it cheap, take a loss and get it out of my way since I'm moving anyway, may just have to junk it, or part it out. I could use the cat on my 97, possibly the exhaust header and downpipe also, and that electric fan that is on it even though it has a mechanical fan. other than that its all going to the junkyard, I already have a 99-06 intake for the 97. To bad the AC works great , will them parts interchange and can I get it off without losing all Freon? Any suggestions on parts I should keep or pricing on parts?

munyanb

I tried two separate coil packs btw, same result. No wonder people just junk them and replace them usually. Anyone in the Chattanooga area need some parts?

munyanb

Oh it's been a while, but the engine knock got fixed by sanding the crank and using another bearing, only to find out the head was no good, typical for a 99 4.0. That whole jeep was a waste of time and money, the only thing I would do with a 2wd jeep would be build it for street racing

dave1123

Maybe. It weighs almost 4000 lbs.

munyanb

Well I got rid of this jeep already, a guy bought it from me for scrap price or less, minus a few parts I robbed for my 97, which screwed up a brand new muffler btw, tried to use the exhaust. I had to cut slits in the exhaust system to un install it, and take two days getting it off without destroying it, then clean it the best I could with water and brake parts cleaner and everything else I could get my hands on. I got it freed up and re=installed, it still tried to plug up a little but it blew more little platinum shavings out and sometimes a piece of glass muffler packing. But it runs now with it and doesn't get red hot anymore.
But yeah regardless of weight, I can see good potential for a street racer out of a 2wd jeep like this, lots of weight can be cut and re-arranged to make them things hook, and I haven't seen one yet so it would be an original project. Anyway this one is long gone from me, maybe sometime in the future I can do something like this but it is doubtful lol