In Fall of 2020 I bought an '08 5.7 4WD Aspen with 146K Miles. It was my son's recommendation, and my first Mopar. Prior owner(s) seemed to take good care of it, and the price seemed right.

So far this has been an awesome truck.. love the Hemi power, great for taking the family skiing, road trips, etc. Installed a PS2 in the back for good measure. I take good care too, change oil every 3-5K miles at the dealership, try to stay ahead of the services, etc.

Here are my issues so far:

Roof leak
In heavy rain, the headliner around the sunroof will get wet, occasionally I'll see water trip to the front passenger carpet. Even less frequently I'll get some minor gremlins.. Sirius went out for 2 days, then came back. Also got a CEL and a few PCM codes once.. In both cases I assumed something got wet, and just drove it a few days, and the issues went away on their own. I clear/flush the sunroof drains frequently, compressed air, q tips, etc..but the drips keep happening.

Clunk or thump when accelerating at 12mph
Dealership initially suggested a transmission flush, which I did, but it did not help. I later found the TSB for the MDS, whIch I also did.. maybe it's a little better now, but not bad. I guess I have to live with that for now.

Ripped Driver Seat
The leather in these things is terrible.. I found a nearby scrap yard with a perfect condition replacement for $150, looks way better.

Spark Plugs/Coils
At 165K I got a misfire, replaced all engine coils and spark plugs with NGK Laser Platinum from a local shop, as the dealership had no appointments. After reading the great spark plug debate I got nervous and asked the head tech at the dealership, he said not to worry, would not change a thing. I since have been getting 18+mpg on highway trips, which is an improvement.

Shocks
The stock shocks are horrible, replaced with some Monroe's and they have been much better.. no more bouncing out of my lane on the highway.

Whats Next
Need new tires soon, will probably get something more off-road capable
Thinking of performance upgrades, maybe a better exhaust, but dealer recommends a cold air intake which I am considering.. just looking for the right one.

Anyway, love the truck. Is good.

 

Welcome to the club. So few of us out here.

Roof Leak - If your drains are clear, then you may have a bad seal on your sunroof. I'd look it over thoroughly. Might even try to refresh the seal. Honda sells a product called "Shin-Etsu" Silicone Grease. It is what they recommend to recondition all rubber seals. Highly recommend it. Honda Part # 08798-9013. Available on Amazon even for $18. A little bit goes a long way on this stuff.

Clunk - I also get a small clunk when I take off from a dead stop. I suspect it is one of the bushings going bad but haven't figured it out just yet. Would like to know more about this TSB for the MDS you mentioned. I've never heard of it and not having much luck finding anything on it. I've got one that is bad so I've had to bypass the entire system with a programmer. Wondering if this TSB would cover that.

Seat - I have a couple small tears in mine and the lower back part is really getting worn. Nice find on a replacement.

Spark - Not bad MPG. I average around 15 so that's a big improvement.

Shocks - Using Monroe's here also. Agree. Much better than stock. Although I am wondering if one of them may be causing the "clunk" noise on take off.

Tires - I've been a big fan of Michelin's. Although a little more expensive, they do get a lot more mileage. However, I cannot speak on any off-road tires. I've never used them.

Performance - I have the AEM CAI and the Magnaflow Cat-Back exhaust. Just love the sound it produces. However, does have a slight "drone" when in MDS mode. Since my MDS is turned off, I don't have that issue anymore. Both were pretty easy to install.

 

Thanks CC for the recommendation on the silicon grease.. I think it may be the seal as well, that will likely be my next priority, a wet interior is not a good thing.

For the MDS TSB, google:18-006-10 REV. B

I still had to pay 1 hour of labor, unlike the fuel neck filler TSB, which was free.

It may have helped slightly, but I can still produce the clunk when trying. Would love to know if it works for you. I've replaced the shocks, flushed the transmission, and did this TSB, and nothing has really solved it. Drives fine otherwise.
Also my wife scraped the rear door yesterday, so now I have a 6 inch scratch to try to fix. Good times!

 

Thanks for the TSB number. Looks like that is a ECU flash to manage the engagement of the MDS. So I'm sure that won't fix my issue. The solenoid itself needs to be replaced. Good to know for when I do actually do get it replaced though. Thanks.

Sorry to hear about the scratch.

 

Roof Leak
I had issue with leaking sunroof at driver side it was the drain hole. Used a smoke pipe cleaner and no issues. Good recommendation on that silicone. Will try that.

Clunk - I switched my ECU to BullyDog tuner in 2019. I get 24MPG on highway around 15 in the city. Payback was 5 months as it activates the MDS more often. However, car needs to be well maintained as if the MIL light goes off it will turn off the MDS. Also, if I drive car before engine heats up. ie. below 1000RPM sometimes I get a clunk on acceleration and afterwards for around 30 min. Nevertheless, I had an MDS issue last year and I changed all of them in one shot as cheaper. Averaged down...

Spark plugs - goes to show on robustness of American cars. Hemi is not DI so it cleans intake valves. So, I started using Seafoam, for another pseudo reason, for intake and crank couple years back and seems car doing fine. This engine is known to run for 500K Miles with proper maintenance. Car has 170K and oil engine flushed twice already at 100 and 150K.
My exhaust bolts broke and replaced that. Tried the premium gaskets lasted two years and went back to original design.

Shocks - I replaced my cross linkage at the rear axle and that did wonders. Eliminated sharp corner skips. Year later Monroe shocks. No more noise whatsoever. Also flushed the rear axle oil at 130K.

Exhaust - if you replace your OEM exhaust with piped headers evenly distanced you will need a (double?) dead-end pipe/resonator to control drone. As system seems to be designed for the urban cowboy. But you may add up to 50HP.
AEM cold intake. CC did you end up with better mileage? or way more power? This is an electronic engine not sure difference would be significant like 10%.

 

Cold Air Intake - I can't say that it did much if any for mileage. It did add to the sound a bit. My MDS is permanently turned off due to one of the solenoids being bad. I really need to replace them. Just difficult as it is my daily and I have no garage to work out of.

I tried that Seafoam once and was not impressed with it. However, my lawn mower guy turned me on to a product called STA-BIL 360 Marine. It is a fuel additive that helps create a vapor barrier in the tank and helps prevent water from getting in the fuel. Helps maintain the octane and helps prevent it from gumming up your carb. It is HIGHLY recommended to add to your lawn mowers when it sits for the winter. One ounce treats 10 gallons of gas. I started using it when the Aspen started stalling out when I would come to a stop. Since using this, I have not had that issue since and my mileage went up 1 point on average with city driving.

 

I use Stabil on my lawnmower, maybe I'll try it on my Aspen. Here are my updates:

Sun Roof Leak
Think I finally solved this one.. pushed a bunch of gunk through the drain channel, using weed wacker line and medium gauge speaker cable. No issues for a few months now, but will keep an eye on this. I bought the silicon grease, have not applied it yet.

Fuel Vapor Leak
Got a p0455 code, indicating large fuel vapor leak. I replaced the gas cap for $30, and that seemed to solve it. Noticed an increase in MPG too. Also purchased a vapor canister purge valve, as that is apparently a common culprit for this code..

MPG
Have seen improved MPG since replacing gas cap and spark plugs. Recently completed a 300 mile trip averaging 19.6 MPG and a 200 mile trip averaging 20.5. I used to have a hard time breaking 18 MPG, so this is great for me.

Performance
Just installed the K&N Cold Air Intake. Have only driven about 50 miles so far, so it's too soon to notice any MPG increase, but it sounds great, and I feel the difference on acceleration. My son and I did the installation in about 2 hours.. also replaced Vapor Canister Purge Solenoid (Part Number: 4891731AA), since it was much easier to access without the resonator/air intake in place, and I had the part on hand. That was more difficult that installing the CAI.. each clip is its own puzzle.

I have a chip tuner, but don't think I'm going to install it.. those things worry me.. sometimes I think they can cause more problems than they solve
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Transfer Case
Back in April, I could not get the car into gear.... towed it to the dealership, had to have the transfer case motor replaced, and front and rear differentials replaced. That was expensive.

Clunk
It's still there.. despite flashing the PCM, servicing differentials, and transmission flush. I guess I have to look into the MDS next. It's not bad, minor annoyance. but it's there.

Otherwise it's great, but hoping for no more big repairs for a while..

 

I highly recommend the Stabil. Use the Marine 360 one. Works for everything. Just be sure to use a marker and record the date on the back of the bottle as recommended. You don't want to use it past the expire date and those bottles can last for a while if you don't travel much.

Sun Roof
Glad you got that clear. Those tubes do clog up on ANY vehicle with sunroofs and cause leaks.

Vapor Leak
It's good that you replaced the cap and vapor purge valve. I agree that those clips on the purge valve are a royal pain to disconnect. However, if you continue to get the P0455 code, I highly recommend replacing the ESIM. Read this thread for more info: https://www.chryslerforum.com/forum/...ge-dash-30554/. Although the prices have gone up a little, about $53.25 for them both, this simple install is what took care of my P0455 code.

Performance
I personally use a Diablo Intune 2 tuner. Got it used from another member on here. It does pretty good. Not a super tuner, (about the size of an iPod) but allows you to make some tweaks. I mainly use it to turn off MDS since I have a bad solenoid and I have it tuned for 93 octane but run 89. I also gave it a slight change on shift times on 3-4.

Transfer Case
I can understand the transfer case motor as an issue. Got that one myself, but both front and rear diffs? Wow. That was bad.

Clunk
This could be something completely unrelated to the drivetrain. I get a small "pop" every once in a while when I take off and turn at same time. I've read that this could be due to some frame bracing. Someone was talking about some kind of "T" brace had a bolt come slightly loose. Had it at the dealer for a while to find and they had to bring in someone from corporate to figure it out. This kind of makes sense since I didn't notice it on mine until I raised the truck up and put a jack stand under one of the braces up front to check the brake pads. Think I may have loosened something.

 

191K on the 2008 5.7 4WD..

Had a groaning/squeaking sound from the front axle when I turned the wheel.. Dealership recommended replacing sway bar links, which I did for about $600. Now the sound is mostly gone..

Replaced tires with some rugged Toyo Open Country all terrain tires. Looks nasty..but more road noise and vibration that I expected

I replaced the ESIM about 10K miles ago (thanks to Calamity for the recommendation and details).. Codes went away after that.

Sirius radio would fail, I suspected the stock antenna was bad, the cable had a short, so I replaced with a new antenna from Best Buy for $50, kept the head unit, and all is good again.

Getting oil change warnings every 3K miles now..lil bit of white smoke on start up

Otherwise she's holding on strong