2008 Jeep JK 3.8 110k

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Dec 29, 2022
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So I have replaced every seal on this motor other than the rear main. Luckily have stopped my leaks for now. Jeep runs really good and doesn't show signs of any major problems. The valve covers and heads were spotless. However, I noticed quite a bit of varnish on the upper case pan and around the timing cover inside the block. Does that seem normal? 3k OCI'S with Valvoline full synthetic. Would a oil like Royal Purple or Redline be better?
 

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Are you the original owner ? Looks good to me. 3k oci , it won't matter what oil you use , as long as it has the approval ratings that your owners manual calls for.
 
Are you the original owner ? Looks good to me. 3k oci , it won't matter what oil you use , as long as it has the approval ratings that your owners manual calls for.
Yep owned since new. At 70k it spun a rod bearing. Many 07/08 Jeeps had issues from what I found out. New short block under lifetime warranty. I was just amazed that it had some varnish when the top looked amazingly good.
 
Yep owned since new. At 70k it spun a rod bearing. Many 07/08 Jeeps had issues from what I found out. New short block under lifetime warranty. I was just amazed that it had some varnish when the top looked amazingly good.
Royal Purple definitely would not have done better. Redline might have kept it cleaner? But, really, it looks quite good.
 
Thanks. Just not use to seeing varnish in a motor that's been well cared for. The more I have read some engines are just prone to a little. The actual moving parts are very clean. I guess the oil temps coming back down from the top end just overtime stain non moving parts. The actual bottom oil pan was spotless.
 
Well looks like it's leaking again. Doesn't seem too bad but, will not know until I pull cover for sure. Every Jeep I've ever had YJ,TJ,LJ and this JKU have always been nuisance issues. This motor only has 110k and everything other than the rear main and head gaskets have been changed. When will Chrysler ever make something decent? Had to put 4.88s in this thing a few years ago because the 42RLE was a poor (IMHO) transmission. I don't think you could pay me a million dollars to own another Mopar product. They are pure junk! Would not bother me for them to go under. They should for the crap they push out the door.
 
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I have a 3.8L (2009) and it's got over 235,000 miles. Runs good and no big issues. Valve cover gaskets twice, and upper oil pan gasket once (lower too, of course). Did have to change head gaskets at 211,000 or so miles, but not really unexpected (aluminum heads, iron block).

Otherwise, a really good engine and very reliable. Sounds like your remanufactured engine assembly may have not been checked thoroughly by the re-builder Chrysler used. At that time Chrysler was having major financial issues and cutting corners everywhere.
 
Major leak pour or a occasional drip?

I'd run a thicker oil or minimally an HM oil and keep driving.

The oil top off rate would determine whether I'd want to seal up every possible leak, or let it drip.
 
Well looks like it's leaking again. Doesn't seem too bad but, will not know until I pull cover for sure. Every Jeep I've ever had YJ,TJ,LJ and this JKU have always been nuisance issues. This motor only has 110k and everything other than the rear main and head gaskets have been changed. When will Chrysler ever make something decent? Had to put 4.88s in this thing a few years ago because the 42RLE was a turd transmission. I don't think you could pay me a million dollars to own another Mopar product. They are pure junk! Would not bother me for them to go under. They should for the crap they push out the door.
I had the annoying leaks in my YJ and even bought a rear main seal to do a replacement. However, Valvoline High Mileage oil put a stop to the leaks.

The only leak I have now is at the transfer case where the driveshaft goes into the case. I’ve changed that seal 3 times.

I wouldn’t worry about your varnish! Try the High Mileage oil for the leaks.
 
Major leak pour or a occasional drip?

I'd run a thicker oil or minimally an HM oil and keep driving.

The oil top off rate would determine whether I'd want to seal up every possible leak, or let it drip.
Minor. Doesn't do it while sitting only after running and on the highway does a little make it onto the inspection cover. Everything else is dry all around pan and top of motor.
 
Where is it leaking from?
Where does it not leak from should be the question. I'm sure if I ever get this leak fixed one will be waiting in the wings within a month or two. Mopar means more parts for a reason. Takes more to keep the pile of crap going. Never ever had any constant issues with a Japanese vehicle. Had an FJ with 175k, Accord with 250k both in their lifetime I can count on one hand how many parts I had to change. Both didn't have issues to well over 100k. Did not need gears, motor are all new engine seals. FCA ought to be embarrassed! The hardtop will sometimes leak a little in the rain. Why is it acceptable for a Jeep to be less than average?
 
Where does it not leak from should be the question. I'm sure if I ever get this leak fixed one will be waiting in the wings within a month or two. Mopar means more parts for a reason. Takes more to keep the pile of crap going. Never ever had any constant issues with a Japanese vehicle. Had an FJ with 175k, Accord with 250k both in their lifetime I can count on one hand how many parts I had to change. Both didn't have issues to well over 100k. Did not need gears, motor are all new engine seals. FCA ought to be embarrassed! The hardtop will sometimes leak a little in the rain. Why is it acceptable for a Jeep to be less than average?
This isn't an FCA vehicle, it's either a Daimler-Chrysler vehicle (depending on whether it was produced before the sale to Cerberus or not) or a Chrysler Holding LLC vehicle, which was just before the 2009 bankruptcy. In either case, certainly not a great period for the industry and particularly GM and Chrysler, who both went bankrupt, or even Ford, who was trying to avoid that same fate.
 
This isn't an FCA vehicle, it's either a Daimler-Chrysler vehicle (depending on whether it was produced before the sale to Cerberus or not) or a Chrysler Holding LLC vehicle, which was just before the 2009 bankruptcy. In either case, certainly not a great period for the industry and particularly GM and Chrysler, who both went bankrupt, or even Ford, who was trying to avoid that same fate.
I understand. I think it says LLC on the door jam. In either case Chrysler has been the laughing stock of manufactures for decades. How they survived as long as they did is beyond me. All three previous Jeeps I owned were pieces of dog crap.
 
I understand. I think it says LLC on the door jam. In either case Chrysler has been the laughing stock of manufactures for decades. How they survived as long as they did is beyond me. All three previous Jeeps I owned were pieces of dog crap.
I've owned three Grand Cherokee SRT's, my first was a '16, it was a great vehicle for the most part, but I got rid of it after an accident in which the body shop didn't do the work properly and I lost confidence in the vehicle being problem-free going forward. I replaced it with a 2020, which I traded on an Audi e-tron because I thought I wanted an EV, which I then traded on another 2020 SRT (my current Grand Cherokee) after my wife hated the Audi and I missed the SRT.

of the three, I put the most time and miles on the 2016, which I owned for 4 years.

I did have an exciting electrical adventure with my current one (one of the capacitors for the ignition, which are mounted on the back of the cylinder heads shorted out, burning the wiring) and a fight with the service manager at my dealer who wanted to repair rather than replace the harness (it was replaced eventually). Could be a COVID thing, but the rest of the vehicle has been perfect, but of course I'm only coming into my 3rd year of ownership with it.

I've never had a desire to own a Wrangler, so perhaps my experience would be different if I had, but I really like the Grand Cherokee as a vehicle and it was a very expensive lesson figuring that out with the Audi detour.
 
I understand. I plan to throw this minivan engine in the dumpster one day or use it as a boat anchor and go with an LS swap. Would do Hemi but, Mopar's are garbage and have been for years. The less Mopar the better.
 
Well I pulled the inspection cover and had no oil around the back of the upper case or anything on the flywheel. The inspection plate had very little oil inside one of the areas but, everything else I looked at was nice and dry. I pressure washed everything just to ensure nothing was lurking around and will keep an eye on it but, so far I see nothing leaking. I'm thinking some oil during the removal made it's way into the bellhousing and got moved around by flywheel. Sorry but, I was just frustrated with having fixed so many seals in the last year. Vehicle runs great so if I can keep the leaks at bay should be good.
 
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