af908

Hi guys,

Got this code today, jeep is sputtering and shaking at idle and when accelerating slowly.

Really dumb question, especially from someone who pulled this motor out twice (its been a couple years im a little foggy). Where is cylinder number 4? Does jeep start with the front cylinder as #1, then 2,3,ect.. and the last as #6, or is it opposite direction. Sorry i forget.

Anyone who has gotten this code, what ended up being the solution? Spark plugs are only 15k miles old, and rebuilt motor and head are only 15k as well, so i dont think it would be the head or head gasket. Coil rail maybe?

Sorry and its a 01 jeep grand cherokee laredo 4.0

Zack92MJ

This is a very common issue it's called hear soak (google* It theres lots if info on it) and I'm pretty sure 6 is closest to the firewall and 1 is closest the front clip

af908

I looked up heat soaking, and this doesnt seem like the case. The car will start fine every single time, even after shutting off when hot (apparently most of the heat soak guys expeirance a tough time getting it to start after hot).

It shakes even when the engine is cold, not to mention my engine bay does not get that hot. Its 32 Degrees here in ct and i also installed a thermostat that keeps the temp around 180-190 max.

Spark plugs maybe?

Apreciate the info on the cylinder numbers, btw.

Zack92MJ

Gotcha, ideas never hurt lol


How old are the cap/plugs/wires?

af908

Plugs were new when i rebuilt the engine so they have maybe 15k over 2-3 years on them ( i only drive the truck in the winter). The coilrail as far as i know is original. I would assume that would cost a pretty penny to replace.

warthog

When I had my 0301 code, turned out to be a cracked head in between the two valve seats in the #1 cylinder. I would suggest a compression ck first then go from there

mikesignal

cheapest thing to do is change the plugs--also not sure what specs are on you grand cherokee but my 2000 XJ is supposed to run at 210....if you run them cooler they will burn more fuel and possibly burn up the cat

mikesignal

could be coil pack---I think it's about $100 to replace.....bad/clogged injector possibly? also the 2000 and 2001 heads in the XJ's had a bogus head in them. I think they were 0331 heads? There have been many issues with them cracking around cylinder 3 and 4. So not sure what head you have in yours.

ss427ci

Did it overheat before the rebuild? If so, did you rebuild the same head and put it back on?
Not saying it is, but if it does end up needing a new head, look for a TUPY casting 0331 head.

Hopefully it's something simple though.

af908

Yeah, it did overheat before the rebuild. Strange thing though the head didnt crack, yet the piston rings melted right to the pistons and even on the cylinder walls. The head didnt crack at all, instead the valves bent which left me with no compression so i bought a remanufactured head.

Thanks for the replies guys, sure enough turned out to be simply the spark plug, and the code even cleared itself. Strange, the plugs were fairly new too, i would have never thought the fix would be that simple.

ss427ci

Good deal! Glad it was something simple.