Checking reliability

[Jeepmedic46]

I have a 2000 Jeep XJ with the 4.0 engine. My wife wants me to have the engine checked out for reliability since I’m disabled she doesn’t want me breaking down. I have a check engine light and I have to replace battery cables. Looking for recommendations on where to send the Jeep. I have 2 places that restore vehicles. One of which has built a 2000 XJ for overlanding for a customer. Other option is sending it to a dealer I’ve worked with before. Next question is what should I have them look for in the engine? Should I have the transmission and 4 wheel drive looked at as well?

 

[smritte]

That's difficult. I dont have a suggestion of where but, more of a what. The engine/trans while a concern, wont leave you stranded as fast as the bolt on parts. You should replace eng/trans with quality as well as what I describe below.

There's a few things you can do but nothing will tell you anymore than guessing. What I suggest is costly but about the best you can do if there's a concern about being left stranded.
Baseline the vehicle with OEM quality or better. Replace with new anything that can strand you. This will put you at a starting point. You can replace parts that wear one at a time, do only what you need but, no one can predict. For example, crank sensor on your vehicle should be replaced around 100k (or sooner). You replace it and you know that will be good for "around" 100k". Once your done with all the bolt on electrical and mechanical parts, your left with wiring. Wiring and connectors are something you cant predict, you just have to look at them and make sure they haven't gotten brittle with age and their being properly held in place still.
Like I said this is expensive. When I buy a used vehicle as a toy or transportation, this is the first thing I do. I have over 10k invested in my cruiser and I still have a few more items. I did all the work.

Getting a mechanic to inspect it is a crap shoot. If you say "I want reliability and don't want to be stranded" a good tech will replace things to give you a starting point (baselining). Now you can say "it should last this much longer".

For this reason, I always had put my wife in a new lease vehicle every three years. One less thing I had to worry about. I spent most of my lifetime in a shop, building things and watching people at my four wheel drive events with the same questions. I have watched too many "cheap" replacement parts fail regularly. I refuse to buy anything critical from an auto part store. Its not worth me being stranded. At my age I really don't want a 3+ day walk out of the Mojave Desert because I cheaped out on something.

Again, this is something I have spent a lifetime figuring out. If your really concerned, you cant settle with "good enough". When your done estimating, now you decide if what your doing can be done by replacing the vehicle with new.

 

[Smileyshaun]

Usually it’s not the engine that fails but what’s connected to it. have every fluid changed but have them filter check the fluids for partials It’s the biggest indicator if a major issue is just around the corner . Next is hoses belts and very importantly the tensioners and idlers just change them but if they aren’t to bad keep them as spares , a worn out belt is better then no belt if things go wrong . A lot of people skip this but replace the battery cables and have a extra ground strap or two installed, most vehicles have just barely enough grounding from the factory so with time and use corroding away at those grounds it can lead to weird electrical grimlins ( jeeps have enough on their own )

 

[smritte]

Forgot to add. "restoration shops" Be careful there. Just because they built an "overlanding vehicle" doesn't mean they did anything more than bolt on parts. I have a resto shop near me. One of my friends daughter married into the family and it was one of the best out here. They will build anything but the cost is huge. They do it correctly. I've seen too many ones that don't. Dealers are about "replace with stock". A dealer isn't set up to do more than replace things, don't go there for modded things. With modded vehicles "you need to be the expert". That means building yourself or knowing what needs to be done and having someone else do the labor.

 

[MMc]

I just went through my 100,000 service, (ouch) ether I did it, or my shop did it. I travel solo and Baja is my go to. Being stranded in Baja can be a multi day adventure, so I try to avoid it as much as possible. Because of the 100k I also replaced alternator, starter, hoses, belts, filters and battery. All parts were OEM except the and fluids and battery. After you go through the drive train and make you stay ahead of all the service work. Most of my problems regarding be broken down I knew about but figured I could “get by, one more time”. I don’t tempt it anymore.
I would get a Spot or a Garmin to stay in touch and SOS.

 

[Downs]

Pull your codes and figure out what they are. With the low cost of bluetooth OBD readers out here now there's no reason to not have one.

Here's what I would do for checking the health of the engine. Buy a vacuum gauge, buy a fuel pressure gauge, buy a compression tester. These are all things you should own as a XJ owner. These vehicles aren't getting any younger and having other's work on it can quickly become cost prohibitive.

Have your vacuum readings checked
Have your compression checked (this is one of the main indicators of engine health)
Have an oil analysis done this will let you know many things.
Have your fuel pressure checked
Have your Cooling system pressure checked.

If the maintenance history of your spark plugs is unknown I would go ahead and replace them. Same for any fluids such as diff fluid. Coolant as well.

Coolant not only removes heat but also acts to help prevent corrosion and as a lubricant of sorts. Over time those additives break down. Also our cooling systems are exposed to a lot of exterior dirt/dust. On the XJ the expansion tank is open to atmosphere. Dust gets into the coolant there then drawn into the radiator when it cools off and draws fluid back out of the tank. Overtime this results in sediment settling to the bottom of the radiator resulting in clogged tubes. I change mine very 2 years or 30k miles minimum. Been kicking around the idea of adding a coolant filter into the system for this reason.

All you can do on the Transmission is do a fluid replacement. Do not let them do a flush. On the AW4 you can drain the trans pan via a drain bolt. It only gets about a gallon of the fluid out but if you do a drain and fill a few times you will have effectively refreshed the fluid in the transmission.

Again not much you can do with the T-case other than change the fluid. You can take the front drive shaft and give it a few twists back and forth when it's empty of fluid and see if you can hear the chain slap the inside of the case.

Check out your head. Pop the oil cap and look down inside the hole with a light. See if you see the word "TUPY" cast into head there. 0331 heads kind of have a reputation for cracking. The later TUPY castings fixed that.

Lucky for you XJs are known for running hundreds of thousands of miles without much issue.


If you were closer I'd say just bring it over and we'd go over it with a fine tooth comb.

 

[ChasingOurTrunks]

4xOverland on YouTube, by Andrew St. Pierre White, recently did a rebuild on an old land cruiser. He bought it used and wanted it brought back up to spec to make it a reliable remote touring rig he could leave in Africa, and fly in and use occasionally.

While your circumstances are not identical, the rebuild process issimilar. Paul Marsh, another experienced traveller, is featured heavily and there’s lots of good ideas in the series of what to look out for. It’s a multi part series but here is part 1:

 

[Billiebob]

what should I have them look

Compression, oil pressure, coolant/rad/heater. O2 sensors, Cats, Clean the throttle body etc. Check all the u-joints, brakes, calipers, wheel end bearing and seals. If it has a clutch and it is shifting well leave it all alone. If it is an automatic, change it for a clutch.... just kidding.

The 4.0L is pretty bullet proof. You don't say how many miles but with basic maintenance mine is at 400K kms.

If it is running strong........ do not touch it, just do all the routine maintenance....
ps use the wifes VISA if it "needs" anything major.