Tune Up!

**jonbeling** · 03-04-2003, 02:50 PM

I have a question for anyone who knows, preferably a machanic. I have a jeep with baout 120k miles on it. It time for a tune up and i was wondering what are the main things that are done. Im aware of the spark plugs, and spark plug cables, but what else is there. Im pretty knowledgeable about cars and i dont feel like paying the jeep dealer like over $300 and have them rip me a new A** Hole when i can do it for $100 Thanks

-Jon

**Steve @ Guru** · 03-04-2003, 03:55 PM

What year is your Jeep? (I was a dealership tech (ASE Master) for about 7 years)

Our typical tune-up included:

- Remove and Replace (R&R) Spark Plugs

- R&R Spark Plug Wires

- R&R Distributor Cap & Rotor (if equipped)

- Clean Throttle Body & IAC (Idle Air Control) Valve (if equipped)

- Flush Cooling System

- Flush Transmission & R&R Trans Filter

- Inspect and R&R Drive Belts as necessary

- Inspect fluid levels (differential, transfer case, etc), top off if necessary

- Change Oil and Filter

- Lubricate suspension & U-Joints (if equipped)

You could get really "crazy" if you wanted to and pack the hubs (if possible), change the differential fluid, flush the brake fluid, etc...

It all depends on your skillset and comfort level with doing your own repairs.

**jonbeling** · 03-04-2003, 09:08 PM

its an 97` grand cheorkee laredo. im comfortable with doing most of that stuff, some i owuld have to look up in a chilton guide or something. Based on your knowledge is it worth bringing a jeep to a jeep dealer to be tuned up or does it not matter who does it? Is there much of a price diference?

**Steve @ Guru** · 03-04-2003, 09:13 PM

For a basic tune-up, it shouldn`t really matter who works on the vehicle. Most quality independent shops should do the same operations to the Jeep that the dealer would. Cost - well, I`m not sure on that...some of the independent shops can be as expensive as the dealer.

**jonbeling** · 03-04-2003, 09:18 PM

im not famillay with pack the hubs what does that entail. The big reason i want to do it myself is casue a basic tune up costs like $200 and that only for like the basic stuff nothing else, and my car has alot of miles on it and needs one real bad so im afraid of having a $500 tune up bill

**Steve @ Guru** · 03-04-2003, 09:41 PM

If your Jeep has serviceable 4WD Hubs (I`m not sure if Jeeps do or not, but I`m leaning toward the 97 NOT having them), then you would remove the front brake assemblies, disassemble the hub assemblies, clean and repack the wheel bearings (i.e. clean grease and "pack" with new grease), adjust the wheel bearings and then reassemble everything.

But, I`m 99% certain a 1997 Jeep does not have hubs that are serviceable, so you shouldn`t have to worry about it.

**jonbeling** · 03-04-2003, 10:09 PM

what about replacing the fuel filter, is that nessacary. I have 120K miles on my car

**aljo** · 03-04-2003, 10:16 PM

Yes you should replace your fuel filter as well.

You might want to have your fuel system flushed as well.

Also, instead of having your tranny oil changed, have the system flushed. I don`t know if it works the same in the jeep, but in my car... If you drain the tranny fluid you only get 4L drained, but 3L is still in your tranny. Having your system flushed will make sure all of your fluid is changed.

**medic** · 03-05-2003, 12:17 PM

the dealer should have a list of services performed during a 120k service. get that and use it as a guide. it`s probably not as comprehensive as what geekysteve listed, but it may have something special they have included based on thier expereience

**jonbeling** · 03-05-2003, 04:19 PM

i have requested a list and they keep telling me that there is no set list for a car with 120k miles on it. However im probally just gonna go above and beyond what really needs to be done, i figure its safer that way. also my drive belt make an annoying noise when the car is idle, can that just be stoped by properly lubercating it or something like that. other than that i just added coolant becasue i was real low and i was wondering if you guys knew weather or not coolant is always being used, because i doesnt seem like the hoses going from the coolant storage container are filled with it and i was wondering if that is a problem or if coolant is just ued when needed.

**Malibu** · 03-05-2003, 04:50 PM

Do not powerflush the ZJ tranny!! I have heard horror stories from Jeep guys who have powerflushed. Just drain, change the filter and refill. Other than that, do what Geekysteve said. The Grands do have a cap and rotor that need replacing. I`d also suggest replacing the fluids in the diffs and 4x4 transfer case. I think my manual actually has what needs to be done for the 120K service. I`ll have to check it (it`s out in the car right now and I`m at work). BTW, fuel filter is a good idea, however, in the ZJs, they are in the fuel tank. You have to drop the tank to replace them.

Mike

**medic** · 03-05-2003, 05:04 PM

for the belt, check to make sure it`s not cracked or glazed. if so replace it and check your tentioners to make sure they are working properly. if all is okay, then get some belt dressing from the auto store to fix it - works pretty well.

for the coolant, it`s bascially used to cool your engine whenever it`s on. so yes, it`s always used. you shouldn`t be running low on it. Although the water portion of the anti-freze can evaporate, it should never be empty.

the "storage tank" is actually an overflow tank. as the coolant gets hot, it will flow into the tank and stay there until the car cools down again and then it should flow back to the radiator. you should keep the coolant level between the max and min lines on the overflow tank. basiclly, fill the radiator to the top and then fill the tank to the middle of the two lines or upto the max if you want.

if you keep having to add antifreeze every few months, you hsould get your cooling system checked out becasue you should only need to add coolant once a year or so and even that shouldn`t be too much.

**medic** · 03-05-2003, 05:07 PM

Originally posted by Malibu

BTW, fuel filter is a good idea, however, in the ZJs, they are in the fuel tank. You have to drop the tank to replace them.

Really, that seems like a dumb design considering the fuel filter is replaced on most vehicles once a year or two. I`ve heard of fuel pumps being placed in the tanks, but those suckers last forever. the fuel filter on all the cars I`ve seen (granted, trucks are different beasts) are all in the engine bay with fuel lines running in and out.

**Steve @ Guru** · 03-05-2003, 05:07 PM

Is the only fuel filter in the tank? I know that on Ford products, there`s a pump filter (looks like a sock that "T"s in at the intake portion of the fuel pump (electric, in tank); but then there`s also a line filter (usually near either the front or rear axle on driver`s side).

I`d be surprised if Jeep only used one, but I`ve seen things more strange!

Re: 120K service "list" - just do what they say to do at the 30K or 60K service. Typically, mfg`s and dealers have what`s called a "30K service" - it`s a major tune-up like what I listed above. Since 120K is = 30k * 4, it would be the same service...

Finally, I just thought about this when I read Malibu`s post - if your transmission fluid has never been changed before, you might not want to change it at all. I`ve seen many the problem arise when an owner decides that after 80k+ miles the trans fluid should be changed...just a word of caution to consider...

(EDIT)

Regarding the coolant: an engine shouldn`t really ever consume coolant. If it`s continually low and requiring you to add coolant, it`s leaking somewhere. Do a pressure test on the system and see if you can find the source of the leak.

Regarding the belt noise: We were advised to never use belt dressings on serpentine systems because the grooves in the pulleys will load up with dirt that gets attracted by the dressing. The result can be noisier belts or even belts that get thrown due to misalignment caused by the dirt. I`d suggest a replacement, and if the noise continues, consider replacing the tensioner.

(/EDIT)

**BradE** · 03-05-2003, 05:13 PM

Also just to add on to what these guys have said, if you flush the coolant you will need to bleed the system for air. Otherwise your temp gauge will be all over the place and you might overheat because you won`t have a true full fill.

Good Luck!