“I hope they do it a lot better then the 80’s Cadillac…that system was a piece of cr*p.”
Yup!
Back in those days, I was driving a limo, part-time, in order to supplement the pathetic salary that I was receiving as a teacher. The other guys at the limo company were only too glad to make sure that the new guy (me) wound up with the nearly-new V-8-6-4 Fleetwood limo. Only after I reported the incredible drivability problems with that car did I learn that their nickname for that ridiculous contraption was the “V-8-6-4-2-ZERO”.
The owner of the limo company advised me that the engine needed to be warmed up for at least 30 minutes (in the summer) in order for it to operate properly, but even with that procedure, I never knew exactly how it would react when I tried to accelerate. It might take off with gusto, or–more often than not–it would cough and decelerate when I was in an acceleration lane, thus placing both me and my passengers in danger.
If I could have strangled the engineers who came up with GM’s V8-6-4 “technology”, I think I would have been tempted to do so.
The problem with disabling a cylinder on an engine in which valve operation can’t be disabled is that the cylinders that are producing the power are going to be struggling against compression in cylinders that are not.
That’ going to mean some serious vibrating, loss of power, and loss of fuel economy.
ok4450, not sure I agree. Yes, the piston will lose energy as it compresses air, but that will be returned as the piston reverses and the air expands. But yes, there will be vibration.
I’d be concerned about oil seepage into the cylinder and building up. How does the engines that are designed to shut off sections handle that? The exhaust stroke would push it into the cat, but that’s not good either.
If I could have strangled the engineers who came up with GM's V8-6-4 "technology", I think I would have been tempted to do so.
I worked for a guy who had one…there was a fix by GM to disable the functionality…and basically just make it a V8. No more drivability problems…but also much worse gas mileage.
I know it’s an old thread but not an old problem. I have a 2013 Grand Cherokee MDS 5.7 Hemi. Bad lifter on #6, three dealers and two Mom and Pop mechanics none of them will repair it 170,000 miles. Dealer 3 says cyl 6 has a hot spot and walls are scored. New engine $10 to 12k. The car itself and everything else is in excellent shape. Still searching for an engine and a mechanic to do it for around $6 to 7K.
Misfires were 30-50% and I was using my odb to manage catalyst temp while driving, lots of coasting ;-). Now at 100% on cyl 6.
I have disconnected the coil and the fuel injector. Pulling the spark plug today because there is a slight bit of new vibration in the engine.
Any comments about how to make the engine run best and longest on 7cyl are appreciated.
I know I’m going to replace the engine and I know it’s a crapshoot to drive it but I am looking for the best configuration options to continue driving it on 7 cylinders. I saw another thread the guy drove his for 3 years this way. Luck?
Leave the plug in. The vibration may actually be worse without it. 7 cylinder engines swinging an 8th dead one will never be smooth. You also don’t want to ingest trash into the cylinder and make things worse.
Two of the mechanics said a rocker on number 6 was not traveling the expected distance. So I assume the valve in question is not opening or closing fully. Not sure which one it is.
At the very least, unplug the fuel injector as well since this can fry the converter and wash the cylinder down of oil, resulting in engine damage as well.
Drive the other car that you put the coil in instead of this one until you get a new coil installed. As mentioned you are going to confuse every sensor in the thing, probably resulting in a whole long list of codes.
Started off 2016 with 2 BMW’s, then kind of went off on Cadillacs and cylinder deactivation, now over to Jeep. What a place we got here. Almost sounds like a case study on short attention span, over time.
