deadspot

Hi All, It's been a while since I've posted to the forum. I've got a 2007 JKU X with 198K miles. The jeeps been good over the years but I've been struggling with a P0300/0303 error code for a few months. I changed the plugs and wires, etc. But the check engine light persisted. Before getting a chance to take it in to get it checked out beyond what I can do, the jeep started shuttering and the engine light was blinking. I took it to one dealer who quickly told me the compression was low in two cylinders and they were hearing noises in the lower engine that suggested the beginning of possible failure. I then took it home and drove it to another dealer with a better reputation (to the best of my knowledge) and they said much the same - that that compression is low and they are hearing lower engine "noise". However, they added that the shutter I was experiencing was due to a bad coil pack. After some reading on the forum I suppose that makes sense. So, that led to a question - while the low compression isn't ideal and the engine noise is a worry, if I changed out the coil pack would I be back to where I was? A 2007 with nearly 200K that could run better but still runs. The jeep is in otherwise decent shape. I asked them to look at the trans and they said they would fix a gasket that's leaking but didn't otherwise feel there were problems. If I go all in and go with the rebuild (3YR/100K warranty), we're talking $6K. They dealer says they don't use Chrysler re-mgf but rather rebuilt engineers (need to get name - can't recall off hand). Alternatively, I take the chance of replacing the coil pack and perhaps I'm back to where I was with an Ok running Jeep with a check engine light for low compression and spend under $1K. They guys at the dealership obviously can't make the decision but they are pointing out the reality of the engine mileage on the 3.8, lower "engine noise" and low compression. I don't want to scrape up $6K but I also don't want to spend more on something new or even used. In the end, I'd like to keep the jeep. I thought I would push out the question to see what others thought and perhaps others have been in the same spot. I should add, while I can do some basic stuff like my oil, brakes, plugs, I don't have the ability or know how to do much more complicated stuff and it's a daily driver - so I can't park it for weeks to work on it. Any thoughts would be appreciated.

jk_sea

Just based on what you said, it sounds like you can have the coil pack replaced and party on for a while, even with low compression.

However, if this is a daily driver and suddenly being without a vehicle could cause issues, I'd definitely start budgeting/planning to either replace the engine or find a new vehicle. It sounds like there's high likelihood that the engine is ready to go (soon).

Might be worth checking around at independent shops to see how much a rebuild would cost on your current engine just to compare pricing.

BuckLisa

How about a Hesco stroker engine.

http://www.hesco.us/products/23139/j...8l-stroker-kit

I believe they do turn key for around $5k. Check with them.

deadspot

I should add that the shop says they use Jasper engines for rebuilds.

LKWJeeper

I'm not a smart man, but I didn't think the JKs had coil packs. I thought it was wired that ran to the ignition coil.

davids2011jk

correct only one coil.

to op... for under $100 and 10 min of your time with super basic tools you could swap the coil real fast and see what you think. if your not happy with how it runs take the coil off and either return it or save it as a back up if you get the motor swapped.

deadspot

That's fair to say. I think when the shuttering occurred I had the sense it was something major. But I should have stopped and done some research. I asked the dealer to go ahead and change out the part - they indicate they determine that was the cause of the shuttering. I also spoke with them a bit more about the problem in the cylinder(s). They said something about the lack of spark in the cylinder due to a faulty coil can lead to damage in the cylinder wall (if I understood correctly). They said they checked one of the cylinders with a scope (?) and could see some damage.

But again, it's hard to say if the coil problem made things worse or maybe worse over time in terms of the engine compression, etc or if they are related but really separate issues. Meaning, with a new coil I'd be back to where I was, albeit an engine with low compression and some noise in the lower end. Because we don't have the budget to even consider a rebuilt at this time, I went ahead and asked them to change the coil and see what happens. If it runs like it did before this shuttering occurred, I will take the time to figure out the best plan forward. Perhaps a trade-in - even if low dollar - on a 2016 is the right course of action! :/

I'll find out this evening when (hopefully) I pick it up.

deadspot

As an update - the coil replacement did get rid of the shuddering. It's back to where it was - a rough idle and some lower engine noise (you'd have to listen closely to realize it's there) as also the check engine light. But I was able to drive like before the shuddering. It occurs to me I didn't get a clear answer on why I still have the check engine light with a misfire code. I am going to call and get clarification. The mechanic said it's due to the low compression in at least one cylinder. I want to assume - but can't confirm - that there is not another issue causing that misfire. As usual, working with a dealer is often a frustrating thing when all they do is push for a rebuild.

deadspot

Just to add a final point on this. In the end, it seems like the coil pack solved the rough running issue. I've drove the jeep for another week and for the most part it was business as usual. And I had the transmission serviced and a small leak taken care of. I sense these dealers see an engine at 200K miles and right away convince you they aren't worth repair. But it would take more investigation to figure out the check engine light. They said they could look at other potential causes for the misfire code including some controller. I decided it wasn't worth putting more money into the Jeep since there were other typical wear items that were coming down the pike including tires. So we ended up selling it and using the money towards a new Jeep!

Mthorn2

Damn. Thats sad to hear. I just hit 187K miles (2007 Sahara 4D 4wd) and am having the EXACT same issue with lower engine sounds and a persistent engine light (faulty No. 4 cylinder). Changed the spark plugs and coil ...to no avail. Also just put on new brake pads and relatively new tires. Opposed to trading it in....I'm just going to drive it into the ground. We'll see how long she lasts. I was really hoping you found an answer beside trade-in....not ready to part ways with my BEAST