I bought a used Jeep GC, it now has a 117k miles. I am going to start running syn oil through it. I am undecided as what oil to use. I am thinking of using royal purple or Mobil 1. Any thoughts?
Andy
Andy
Oil Change for 2002 Jeep GC
- Thread starter Andyfender
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4.7? 3.7? 5.9?
M1 or royal purple would be good choices, but first can you tell us more about your Jeep GC.
The engine is a V8 4.7. Runs well, no burning oil. The oil was changed every 3k by the original owner. I was lucky enough to get all the service records from the dealer.
Andy
Andy
Castrol Edge 5W-30
PP?
at least you were lucky to get one that was well-maintained. there seems to be many dodge motors out there (the 2.7, the magnums, some 4.7) that sludge up and clog the oil pickup. if you have the coin for redline, great! otherwise I have always given mine a diet of M1 or Amsoil
What oil did the dealer use?
Hello Andy,
A few more details will really help in making recommendations:
What is your driving style? (lead foot? Grandma?)
What is your climate like? (minimum and maximum temps where you live?)
Will you be towing, drag racing, going over mountain passes with the AC on full blast?
Will you use the vehicle off-road in low range to go "back-country?"
The more you can tell us about how you will be using the vehicle and in what possible weather considerations, the more precise the recommendations can get.
Eric
A few more details will really help in making recommendations:
What is your driving style? (lead foot? Grandma?)
What is your climate like? (minimum and maximum temps where you live?)
Will you be towing, drag racing, going over mountain passes with the AC on full blast?
Will you use the vehicle off-road in low range to go "back-country?"
The more you can tell us about how you will be using the vehicle and in what possible weather considerations, the more precise the recommendations can get.
Eric
I believed the dealer used Kendal Syn blend 5w-20. On the oil fill cap it also says Kendal Syn Blend.
Driving Style = Moslty suburban driving to and from work. No lead foot.
Climate: North East, four seasons. Winter can vary, lows are around 10 degrees f. Summers highs 90f.
Towing: Will be towing a 14' bass boat. Total weight with trailer about 1200 lbs
Off Road: No
Driving Style = Moslty suburban driving to and from work. No lead foot.
Climate: North East, four seasons. Winter can vary, lows are around 10 degrees f. Summers highs 90f.
Towing: Will be towing a 14' bass boat. Total weight with trailer about 1200 lbs
Off Road: No
The 4.7L is a known sludger even with routine maintenance due to a poor crankcase ventilation system. I would pull and check the PCV 1st and foremost( best to change it unless you know if and when last done ). Also look under the oil fill cap and into the valvetrain( what you can see )for any "goo" and build up. If you find anything or the PCV is loaded up/failed then plan on some kind of flush( Seafoam, Amsoil's flush, Auto-RX, MMO, or whatever you want ).
If everything seems ok you can make the swap over. I would do at least one quick OC, and probably 2( 1000-2000 each ), just to make sure everything is cleaned out due to the known problems with that engine and sludge( even on a quality oil and timely OC's being done ). I personally would run some Seafoam each time as well. I would use a decent, cheap dino oil(PYB, MTC, etc... )along with a good filter, for the runs with the Seafoam, then go to the synthetic of your choice if the oil looks good when it comes out. You should also check the filter to see how loaded up it is as well. Might take 3+ short OC's with a flush product if the engine is sludged bad or one may do it if not.
Kendall oil on the whole, be it dino/blend/full synthetic, is actually very good. If you want a full synthetic that is affordable and is a good product their GT-1 full synthetic( now with Liquid Titanium
) is very good stuff and pretty cheap. $4.99 p/qt at pepBoys.
Between Royal Purple and Mobil 1 I would chose the Royal Purple. I am an admitted RP fan however and also an admitted detractor of Mobil 1 oils. If you like Mobil 1 however it would do the job. I would pick Kendall over Mobil 1 in a heartbeat though. I would also take Penzoil Platinum, Valvoline Synpower, and Quaker State Ultimate Durability( HP ), over Mobil 1 oils too. That is just me.
Hope this helps and good luck.
If everything seems ok you can make the swap over. I would do at least one quick OC, and probably 2( 1000-2000 each ), just to make sure everything is cleaned out due to the known problems with that engine and sludge( even on a quality oil and timely OC's being done ). I personally would run some Seafoam each time as well. I would use a decent, cheap dino oil(PYB, MTC, etc... )along with a good filter, for the runs with the Seafoam, then go to the synthetic of your choice if the oil looks good when it comes out. You should also check the filter to see how loaded up it is as well. Might take 3+ short OC's with a flush product if the engine is sludged bad or one may do it if not.
Kendall oil on the whole, be it dino/blend/full synthetic, is actually very good. If you want a full synthetic that is affordable and is a good product their GT-1 full synthetic( now with Liquid Titanium
Between Royal Purple and Mobil 1 I would chose the Royal Purple. I am an admitted RP fan however and also an admitted detractor of Mobil 1 oils. If you like Mobil 1 however it would do the job. I would pick Kendall over Mobil 1 in a heartbeat though. I would also take Penzoil Platinum, Valvoline Synpower, and Quaker State Ultimate Durability( HP ), over Mobil 1 oils too. That is just me.
Hope this helps and good luck.
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Originally Posted By: Andyfender
I believed the dealer used Kendal Syn blend 5w-20. On the oil fill cap it also says Kendal Syn Blend.
Driving Style = Moslty suburban driving to and from work. No lead foot.
Climate: North East, four seasons. Winter can vary, lows are around 10 degrees f. Summers highs 90f.
Towing: Will be towing a 14' bass boat. Total weight with trailer about 1200 lbs
Off Road: No
It say`s that on the oil cap? Like GM car`s that have the Mobil-1 oil cap?
I believed the dealer used Kendal Syn blend 5w-20. On the oil fill cap it also says Kendal Syn Blend.
Driving Style = Moslty suburban driving to and from work. No lead foot.
Climate: North East, four seasons. Winter can vary, lows are around 10 degrees f. Summers highs 90f.
Towing: Will be towing a 14' bass boat. Total weight with trailer about 1200 lbs
Off Road: No
It say`s that on the oil cap? Like GM car`s that have the Mobil-1 oil cap?
I have never seen the 4.7 sludge up. The only thing wrong with the PCV valve is it sucks. The valve barely has any vacuum and that is why you get that milky "sludge" on the filler cap and the only reason. But the 4.7 is tough on oil. I've ran Synpower 5w30 in mine for nearly 50k. Doesn't burn a drop and is silky smooth and no noise. Motor is nice and clean inside to boot. I vote Synpower.
Originally Posted By: 47HO
I wonder why the dealer used 5W-20, when a 5W-30 is spec'd?
My error it is 5w-30.
I checked the oil with about 2500 miles on that batch, and it is very clean as well as the filler cap. No goo or anything like that.
Andy
I wonder why the dealer used 5W-20, when a 5W-30 is spec'd?
My error it is 5w-30.
I checked the oil with about 2500 miles on that batch, and it is very clean as well as the filler cap. No goo or anything like that.
Andy
Originally Posted By: sparkplug
I have never seen the 4.7 sludge up. The only thing wrong with the PCV valve is it sucks. The valve barely has any vacuum and that is why you get that milky "sludge" on the filler cap and the only reason. But the 4.7 is tough on oil. I've ran Synpower 5w30 in mine for nearly 50k. Doesn't burn a drop and is silky smooth and no noise. Motor is nice and clean inside to boot. I vote Synpower.
Do a search on 4.7L sludge problems and sit back for some long reading.
I have never seen the 4.7 sludge up. The only thing wrong with the PCV valve is it sucks. The valve barely has any vacuum and that is why you get that milky "sludge" on the filler cap and the only reason. But the 4.7 is tough on oil. I've ran Synpower 5w30 in mine for nearly 50k. Doesn't burn a drop and is silky smooth and no noise. Motor is nice and clean inside to boot. I vote Synpower.
Do a search on 4.7L sludge problems and sit back for some long reading.
Considering use and application, also that the original owner kept that OCI probably unnecessarily short, means you should have a nice clean slate to work from. Continued use of a syn-blend 5w30 would probably be perfectly fine year round if you were going to continue doing oil changes in the 3-4K range. If you move up to full syns, run longer intervals, like 5-6K without a UOA, even longer may be achievable through the occasional confirmation with a UOA but I have been developing reservations about the cost of doing UOAs vs just changing the oil more often. I guess depends on how much you want to tinker. One other "tinker factor" you might consider, is running a 0w30 year round, or a 0w30 in the winter, and a 10w30 in the summer. All sorts of options to play with and it's hard to go wrong. Go with whatever brand helps you sleep at night 
If the sludging reports turn up true then you'll probably want to keep those OCIs under control regardless of what you run.
If the sludging reports turn up true then you'll probably want to keep those OCIs under control regardless of what you run.
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Originally Posted By: mdocod
Considering use and application, also that the original owner kept that OCI probably unnecessarily short, means you should have a nice clean slate to work from. Continued use of a syn-blend 5w30 would probably be perfectly fine year round if you were going to continue doing oil changes in the 3-4K range. If you move up to full syns, run longer intervals, like 5-6K without a UOA, even longer may be achievable through the occasional confirmation with a UOA but I have been developing reservations about the cost of doing UOAs vs just changing the oil more often. I guess depends on how much you want to tinker. One other "tinker factor" you might consider, is running a 0w30 year round, or a 0w30 in the winter, and a 10w30 in the summer. All sorts of options to play with and it's hard to go wrong. Go with whatever brand helps you sleep at night If the sludging reports turn up true then you'll probably want to keep those OCIs under control regardless of what you run.
I will probably go with Mobil 1. I am going to change my oil every 3k regardless.
Andy
Considering use and application, also that the original owner kept that OCI probably unnecessarily short, means you should have a nice clean slate to work from. Continued use of a syn-blend 5w30 would probably be perfectly fine year round if you were going to continue doing oil changes in the 3-4K range. If you move up to full syns, run longer intervals, like 5-6K without a UOA, even longer may be achievable through the occasional confirmation with a UOA but I have been developing reservations about the cost of doing UOAs vs just changing the oil more often. I guess depends on how much you want to tinker. One other "tinker factor" you might consider, is running a 0w30 year round, or a 0w30 in the winter, and a 10w30 in the summer. All sorts of options to play with and it's hard to go wrong. Go with whatever brand helps you sleep at night
If the sludging reports turn up true then you'll probably want to keep those OCIs under control regardless of what you run.I will probably go with Mobil 1. I am going to change my oil every 3k regardless.
Andy
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