ZaneJK

Hello folks

I installed the 6.4 VVT in my wrangler unlimited few months ago and till today im an unhappy camper to say the least!


Just wondering who here is running this motor and if your having any problems at all. If so what sort of problems etc etc

Id like to hear what others have experienced.

Thanx in advance

Zane

txjeeplover

Why are you unhappy with the 6.4VVT motor? Which kit or installer did you use? I'm about 2 years away from installing that same motor and I'd appreciate your feedback.

Yankee

I too would be interested in what problems your having. Who did the install and what kit was used? I am not sure what is different between installing that motor and a 5.7/6.1.

ZaneJK

Well its not the actual motor that im not happy with... its a beast of a motor! but am sure somethings either wrong with the install or program or the transmission or transmission tuning or SOMETHING

I bought the motor from Burnsville and was shipped out to me here and had it installed locally. The shop that installed it is the first to shop here to ever install 6.1 HEMIs in JKs successfully and been doing it for years... but this is their first 6.4 VVT install and it didnt go well!

First prob was overheating.... and it is HOT where i am. Anyways we put the bigass aluminum radiator and stuck an electric fan on it... seems to have resolved the issue a bit but i still run hot when i gun it.

Second... the tranny doesnt downshift consistently on demand... it rather laggs a lot after i hit the throttle then after a bunch of seconds it decides to explode into gear then go.

Third... power seems to cut off after 140km/h when car has been run hard... done it a few times... going 120 then mash the pedal and brrrrrrrrrrrr nothing...

Aaaaaaanyways and many other issues... basically the performance is not there! somethings wrong but the shop tells me theyv done everything they can do.

So now and after a big dent in the wallet im stuck!!

Yankee

Zane,

Who did you get the PCM and conversion kit from? Burnsville? It may just be a bad PCM program.
If all the wiring is connected right, maybe try to get a different PCM from the source?

Have you checked for any codes being recorded?

There was often some shifting mismatch between the 6.1 and 545 tranny (you are using the 545?), some had it worse than others. But nothing like you describe. Never heard of anyone having problems with the engine cutting out.

I assume they used a Procal or something to initially set the throttle travel, axle gear ratio, tire size?

ZaneJK

I got everything from Burnsville! When everything arrived and installed.. the PCM was bad so we got sent another one which is the one on now.

There was some codes yes.. i dont remember what they were but something to do with the o2 sensors. and now that iv removed my cats, the check engine light is always on :/

I am using the 545 tranny yes! Could the tranny be slipping perhaps?

The other day i had it in neutral and stepped on the gas reving the engine high then the jeep jumped a little :s

txjeeplover

If you removed the cats, the downstream O2 sensor isn't detecting a change in the pollutants so the PCM is throwing codes and retarding performance to prevent damage. If you're going to remove the cats (which I discourage) you can have the PCM custom programmed to eliminate the after cat O2 sensor.

But it definitely sounds like you're encountering a programming issue. I follow these HEMI problems as best I can and I do recall another guy having a bad 545RFE tranny that was the culprit when he had similar symptoms. But he had a used transmission that was bad. Correct me if I'm wrong, but isn't Burnsville using new transmissions with upgraded performance internals worthy of 600+ hp?

Does your kit allow the usage of the factory 6.4VVT intake (throttle body facing driver) or the 5.7VVT intake (throttle facing front center)? Again, thinking about programming, you could have programming for the 5.7 instead of the 6.4 so the intake baffles inside the intake manifold could be responding as they would to the 5.7 and not the 6.4 and the transmission is shifting improperly for the same reason.

BTW, thanks for sharing your situation with us! It sucks that you're having to go through with this and I hope you find a solution that gets you the performance for which you paid.

Yankee

Zane,

Burnsville is successfully building 6.4 JK's, so it is likely they sent you the complete engine you need.

My install involved aftermarket hi-flow cats. Have you talked to Burnsville about the effects of running without them? It seems to me that even on 3.8 engines, if they are removed, as posted above, it will cause problems. It may even throw the PCM into "limp mode".

Personally, I would put some hi-flow cats on. With the horsepower you have, you are not going to lose enough to notice having them there. What back pressure they produce might even help low end torque.

You could have two issues. PCM problems due to the confused O2 sensors, and tranny problems apart from that. But I would start with the cat/PCM problem, and work to get rid of all codes.

I certainly ain't no expert, just trying to help.

ZaneJK

Guys thanx much for the input... I guess my best bet is to call Dan.

As for the cats ya i had them removed and am running a straight pipe instead..

stormcup

i also just finished installing the 6.4 Hemi with a Getrag 235 manual in my 2 door JK 2011 in AEV (Dubai) 3in lift Tera flew...and the drive belt fell off after a few hundred Km of driving i felt the powersteering was out and the engine overheated so i stopped and found the belt loose.....took it to the dealer and found out that the alternator pulley was broken .....any one had a similar experience to share ? just wanted to hear your thoughts