New (to me) 97 XJ Owner

Just bought a 97 XJ 4.0 off an older sibling for trade-in value. Dealer offered $1500, she sold it to me for $1500. Anyway, it's $1500 because she abused it pretty badly. All the pieces are there and no dents other than pings and such, but she did not take care of the engine. Currently 120,000 miles on the odometer. She bought it a few years old and proceeded to do nothing but drive it and fix anything that broke along the way like the water pump, etc. When pushed for the info, she never had it tuned-up, she (maybe) had the oil changed every year or so, and never did anything else in the way of maintenance. I guess that's a testament to the Jeep, but will learn as I go.

Anyway, for now the jeep runs fine except for a few things. The main problem I notice from driving it for the past week is that sometimes (but not everytime) when I start it up after driving it, say after getting something from a store, it takes 4-5 seconds of cranking with no luck, then turn the ignition off and try again and it fires right up. When it does fire up, it will blow a bunch of white and black smoke for about 30 secs and act like it is about to die with the rpm bouncing around 500-1000. If I put it in gear during this 30 secs it will have no power whatsoever and will die if I hit the gas pedal. After 30 seconds though, it will go right back to normal as if nothing happened. It does not blow smoke at any other time. It also does not do this on a cold start in the morning after it sits overnight.

Question is, if I throw a tune up and injector cleaner on it will that fix it, or does this sound more sinister?

i would star with the basics plugs, wires, cap, rotor, throttle body is problably filthy inside.(yes the do need cleaned) do a compression check. basically if you question it atleast have it looked at or just flatout replace it.

some might object to this, but you might wanna invest in a case of seafoam

Actually if you are planning on keeping it you might want to consider getting a couple of things done first by a shop
Machine cleaning of the oil system
Maching cleaning of the cooling system
Machine cleaning of the fuel system
Machine cleaning of the auto trans which I am assuming it has
Once they are done take it home, slap in factory OEM cap, rotor, wires and champion copper plugs, new air cleaner. Then see how it runs.
From there I would also do a thorough grease job, check the brakes, rotors and pads are easy. Change both differential fluids.
Order a factory service manual from the back of the owners manual if you have it or from the dealer.
Just my thoughts..
Oh, I would also replace the serpentine belt AND the idler pulleys, hoses to if they are original as well as the thermostat. Once the shop is done the other stuff is a half day in the driveway once you have all the parts.

Thanks RichP. Don't have the moola to take it to a shop to get all that done. Going to spend the weekend replacing all the fluids, hopefully new oil won't jar something loose. Gonna go with synthetic.

Funny you mention brakes. I'm suprised they work at all with the grooves in the front rotors. Thankfully from what I've read here the front rotors are a piece of cake to replace. I assume I'll have to do the rear too.

Baby steps.

Next up will be some 235/15s to replace the weak looking 225s. Why did Jeep ever go with 225s, they look kinda silly, especially now a days when even the tiniest of SUV's has 16" wheels. Anyone have anything good or bad to say about Yoko Geolandar A/T+II’s? I do about 60% city, 20% highway and 20% dirt roads.

tonrow said:

Thanks RichP. Don't have the moola to take it to a shop to get all that done. Going to spend the weekend replacing all the fluids, hopefully new oil won't jar something loose. Gonna go with synthetic.

Funny you mention brakes. I'm suprised they work at all with the grooves in the front rotors. Thankfully from what I've read here the front rotors are a piece of cake to replace. I assume I'll have to do the rear too.

Baby steps.

Next up will be some 235/15s to replace the weak looking 225s. Why did Jeep ever go with 225s, they look kinda silly, especially now a days when even the tiniest of SUV's has 16" wheels. Anyone have anything good or bad to say about Yoko Geolandar A/T+II’s? I do about 60% city, 20% highway and 20% dirt roads.

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120k?
to late for full sythetic run blend

Fred85 said:

some might object to this, but you might wanna invest in a case of seafoam

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Seafoam is the biggest scam.. i tell you...

Seafoam a scam, how? I have seen it work multiple times at my fathers shop. Mostly Volvo, but still a motor.

mdl said:

Seafoam is the biggest scam.. i tell you...

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it works i tell ya, it works

tonrow said:

Going to spend the weekend replacing all the fluids, hopefully new oil won't jar something loose. Gonna go with synthetic.
.

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its a bad idea to put synthetic in an engine thats that old and has that kind of milage on it. what happens is the gaskets such as the rear main seal, oil pan, valve cover.... erode over time, but leaks are prevented because little bits of junk from the oil go in and fill those small passages in the gaskets/seals. when you run synthetic, you're putting an oil in the vehicle that has a lot of detergents. those detergents will clean out the inside of the motor, but more than you want. next thing you know, its going to be springing oil leaks. one more thing to fix.
at the most i'd put a synthetic blend, but would never go all out synthetic in a motor with 120k on it.

God I'm tired of seeing people say this, for the record:

Today's synthetic oil has less detergents in it than today's high quality dino oils!! They need far less additives (including detergents) because they have refined their synthetic base stock to such a level as they are not required.

Now, 5 or 6 years ago when synthetic first began to get so popular, there were a lot more additives in it and, as such, there were some reported problems (never varafied, by the way) of seals that were already damaged "letting go" (which they're going to do in the relative near future anyway). In response to this rumor of too many detergents, true synthetic companies (such as Mobil1 and Amzoil) have further refined their base stock to the point that they have less detergents (and other harmful additives, please don't get me started) than dino oil.

Bottom line, regardless of how many miles you have on your engine if you want to protect it, use synthetic. Interesting read, look at some of the trials performed on the motors (some with high miles, some new) and the results between the two oils:

http://www.getahelmet.com/jeeps/tech/syntheticoil/.

dynamite44 said:

its a bad idea to put synthetic in an engine thats that old and has that kind of milage on it. what happens is the gaskets such as the rear main seal, oil pan, valve cover.... erode over time, but leaks are prevented because little bits of junk from the oil go in and fill those small passages in the gaskets/seals. when you run synthetic, you're putting an oil in the vehicle that has a lot of detergents. those detergents will clean out the inside of the motor, but more than you want. next thing you know, its going to be springing oil leaks. one more thing to fix.
at the most i'd put a synthetic blend, but would never go all out synthetic in a motor with 120k on it.

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