Is it smart to do a full preventive maintenance service after buying a 100K mile TJ?

[jeepwindowshopper]

Hey,

After reading several posts about the recommended 90K/100K miles maintenance list and even stumbling upon the TJ Service Manual, what are your thoughts on the following list of things to get serviced after purchasing a used TJ with around 100K miles on it?:

• Oil Change
• All fluids (engine, transmission, transfer case, differential, axles, cooling system, new brake fluid)
• Air filter
• Oil filter
• Serpentine belt
• Spark Plugs
• Water pump
• Thermostat
• Thermostat Housing and Gasket
• Upper and lower heater hoses
• Upper and lower radiator hoses
• Radiator
• Radiator cap
• O2 sensors
• Crankshaft Position Sensor (CPS)
• Idle Air Controller Valve
• Ball Joints
• U Joints
• All Brake Pads & Rotors

Which are a must do vs unnecessary (if any), given that most of these parts could be almost 20+ years old? I'm trying to think about the best approach for purchasing a used TJ without knowing its true service history, but nervous about the total price for all this!

Thanks!

 

[Grenadiers]

Get a Carfax report for one, two, get service records if private party purchase. Dealers tend to throw that stuff away. Find out if Jeep was maintained or neglected before replacing parts it doesn’t need.

 

[97TJNM]

In the 3 years since I've owned mine (bought with about 145k miles on it) I've done everything struck through in red, and well as a bunch of other stuff.

The thing is, these jeeps are really easy to work on, and diagnose. O er 3 years, I haven't really noticed the cost because any one of those things I've done wasn't very expensive if you are willing to turn your own wrenches.

There's tons of YouTube videos on all of this, and there's a bunch of knowledgeable people here willing to help when you have a question.

I wouldn't fret. Start with the easy stuff. Changing fluids, checking brakes to see if they need replacement, checking hoses and belts for cracking, replacing what needs it.

By the time you are ready to tackle bigger stuff, you will have built skills and knowledge, and have a better idea of what questions to ask (and what videos to search) to tackle them.

 

[Rickyd]

Don't replace electronics that aren't broken.ESPECIALLY with anything but factory parts

 

[tr21triton]

just bought another one myself with 95k miles on it. my plan is to zero time all fluid ,filters and spark plugs at 100k. the sensors and other things will leave alone until they need replacing, sometimes we replace shit that doesn't need changing and cause more trouble than needed. BUT i am collecting things like a OPDA and 02 sensors to have on hand when needed.

 

[sab]

I'd do the top 6 items on your list because those are easy, and most of them are difficult to determine age/condition. The rest of the list, I'd replace as I encountered issues. With quality parts being hard to find these days, keep the good OEM parts on there as long as they are working!

 

[CreepinDeth]

Fluids & filters, yes
Belts, hoses, brakes & rotors are a visual inspection

Electronics?? No….not unless bad
Many people are buyin Chinese knockoffs from Amazon or Ebay and having alot more problems

Leave the cooling components alone unless its visually fubar or not cooling

Ball joints, U joints have someone look that knows ehat theyre doing for you

 

[jeepwindowshopper]

In the 3 years since I've owned mine (bought with about 145k miles on it) I've done everything struck through in red, and well as a bunch of other stuff.

The thing is, these jeeps are really easy to work on, and diagnose. O er 3 years, I haven't really noticed the cost because any one of those things I've done wasn't very expensive if you are willing to turn your own wrenches.

There's tons of YouTube videos on all of this, and there's a bunch of knowledgeable people here willing to help when you have a question.

I wouldn't fret. Start with the easy stuff. Changing fluids, checking brakes to see if they need replacement, checking hoses and belts for cracking, replacing what needs it.

By the time you are ready to tackle bigger stuff, you will have built skills and knowledge, and have a better idea of what questions to ask (and what videos to search) to tackle them.

View attachment 463768

Thank you! This sounds like solid advice and makes sense to start small before trying to get everything fix at once! The ones you highlighted in red also seems to match what others are saying! Awesome!

 

[jeepwindowshopper]

Fluids & filters, yes
Belts, hoses, brakes & rotors are a visual inspection

Electronics?? No….not unless bad
Many people are buyin Chinese knockoffs from Amazon or Ebay and having alot more problems

Leave the cooling components alone unless its visually fubar or not cooling

Ball joints, U joints have someone look that knows ehat theyre doing for you

Ok this makes sense! Basically do the normal stuff first, replace electronics with factory parts once they break, and just have the bigger/more complex stuff done by a professional. Thanks!

 

[Danarch]

I always change all the fluids, except the coolant. For the coolant I see how it looks, how the radiator seems to look and leave it alone If all looks good, that combined with the temps being normal I am good. The other fluids can’t really tell without removing them. The other stuff depends on how it runs and everything looks. If it runs well and things look good, I start doing the maintenance by the service manual. At times I’ll change other items when I get to it. For instance I have tstat, water pump, upper and lower radiator hoses, heater hoses, clutch fan etc. sitting in the garage to change out. Easy enough to do, mostly OEM parts for the important stuff. Cost was reasonable and bought a little at a time.

 

[Zorba]

Belts, hoses, coolant and water pump. All oils. Inspect plugs.

When I bought mine, I did all this except the water pump. I knew better, and I didn't do it. Sure enough, it failed shortly thereafter.

 

[tr21triton]

I always change all the fluids, except the coolant. For the coolant I see how it looks, how the radiator seems to look and leave it alone If all looks good, that combined with the temps being normal I am good. The other fluids can’t really tell without removing them. The other stuff depends on how it runs and everything looks. If it runs well and things look good, I start doing the maintenance by the service manual. At times I’ll change other items when I get to it. For instance I have tstat, water pump, upper and lower radiator hoses, heater hoses, clutch fan etc. sitting in the garage to change out. Easy enough to do, mostly OEM parts for the important stuff. Cost was reasonable and bought a little at a time.

thats really the smart thing being some parts that work are getting hard to find. I have a 05 RUBI and my brother has a 06 Rubi. we have 2 sets of NTK/NGK 02 sensors and 2 CROWN OPDA's because we will own these until we die or they get destroyed in a wreck. I keep a plastic tote with these spare parts so I can find them when needed

 

[bucky]

PO had all maint. records. TJ had 113K so I did nothing until next scheduled maint. 6 months after purchase I replaced injectors and plugs due to P303 code. I inspect belts, hoses, ect before each trip. Never had a water pump fail without giving notice. These days the chance the replacement part being crap I’ll wait for failure. Just me.

 

[TurboTJ]

Get a new mopar radiator if you can find one. I think 100k is about all you can expect from one. The plastic case on the top will crack.

 

[jeepwindowshopper]

Thank you everyone that replied! This information has been extremely helpful!

After taking into account what everyone said, it make sense to focus on changing all the fluids, filters, belts*, hoses*, brakes* (*if needed) as first priority. Next, inspect the other things I listed and replace if it's needed now and if not, simply replace whenever I start experiencing recurrent issues. In the meanwhile, I should slowly stock up on OEM parts that I may need in the future, it case they become out of stock when I later need them.

 

[AzJeff]

Get a new mopar radiator if you can find one. I think 100k is about all you can expect from one. The plastic case on the top will crack.

Yep. I did all of the usual baseline items and didn't replace the radiator. Never have in a used vehicle before. Sure enough the top tank cracked. Got a Denso that visually is identical to OEM which are hard to find and kinda expensive.