Does anyone have any advise in purchasing a a 4.0 from a junkyard. I've found a few with less than 100k for $500-$600 and am going to go take a look at them soon. My plan was to pull the plugs on it, see what the oil looks like, and check for metal shavings, and go from there. Does anyone have any suggestions as to what to look out for? Any help is appreciated.

Thanks,
Taylor

 

Pull the oil pan & check a rod and a main with plastigage. You should probably change the oil & water pump since it would be wide open anyways. Make sure you can exchange it if it's FUBAR.

 

See if the crank turns. X2 about exchanging it. Check freeze plugs, look at flywheel for cracks. Pull valve cover check out valve train if you can.

 

My advice? Don't buy it unless you're going to give it at least a minor overhaul (bearings, rings, cleaning, hone cylinders, and the like.)

Bear in mind that you don't know what the engine has been through before it got to the JY, and you don't know how weathered it's gotten since it got there.

Chances are good you won't be able to check the oil - it will probably be drained. And, many junkyards drain the oil by drilling holes in the sump, so don't expect the sump pan to be in good shape (ditto axles.)

 

$600 seems kinda high for untested JY motor

 

x2, check your local craigslist. I you can't find an engine you can probably find a wrecked running XJ.

 

and don't focus so much on mileage. These engines are good for well over 250k with proper maintenance. That's what I look for signs of

 

you can buy remanufacture engine with warranty for 1000-1500 check ebay
some of seller give you warranty up to 100,000 miles

 

X2 on craigs. I get 150k mile 4.0s for 2
$200-$500

 

1) everything in the scrapyard has "less than 100K miles", lol. No it doesn't.
2) get a warranty- at least 30 days
3) find a donor with severe body damage. If the body is good it's there for drivetrain reasons. A recent wreck is good, the longer they sit the more they rust internally.
4) Plan on doing rings bearings and gaskets at minimum. Be pleasantly surprised if you don't have to. If you can pull the pan and valve cover before buying- do it and take a good look. Check for oil sludge in the airbox. Check for super-clean plugs that indicate burning coolant. Run your finger around the exhaust to see what it was burning when it was last run. Any sign of water or coolant in the oil pan, dipstick or under the VC- move on. Even though they drain the oil there should still be a light oil film. If not it's sat too long.
5) I agree wholeheartedly on finding a running donor on CL if you can. There is no substitute for seeing the motor run. If that isn't an option, *then* go the salvage route.

 

My advice (Which someone just beat me to LOL) is to find one that looks like it was well cared for but which was involved in some sort of side or rear impact crash that resulted in the insurance company writing it off as "totaled". If a 4.0 is in a Jeep that looks rough or isn't seriously damaged then I'd assume it had an engine or transmission problem.

 

If you see big globs of orange (or any other color) RTV around the valve cover, water pump, and oil pan, walk away from it.

 

You want my opinion because I worked in the salvage business for almost 10 years.
1. Buy from a reputable yard that offers a good warranty. Find out what their warranty entails for problems. Also see what types of warranties they offer, the better they are the more the yard takes pride in what they are selling. My old work offers a 1 year parts and labor warranty with engines and transmissions, they check their stuff out or else they would be screwed with labor issues.
2. Find out what basic testing they do on the engine. Some do full compression and oil pressure testing and run the engine.
3. I would buy a engine off craigslist unless I heard it run in person. Don't buy prepulled from some yokle. You might be buying his core.
4. expect to replace basic gaskets, not rod and main bearings or honing the bores. Then its a bunk motor and if you buy from a reputable yard you won't have the problem.
5. 99.9% of the yards will not let you tear into the engine so you can look at the bearings. Why would a business have some 16 year old kid root around in his engine?
6. What type of yard are we talking? A full fledged yard or a you pull type yard?
7. Get in writing the engine mileage on the receipt
8. Look at how the business looks, are they a clean looking yard or a grease spot on the horizon.
9. To get many different options try www.car-part.com you can look up a application and see what yards have inventoried.

I have bought many engines and transmissions from different yards and have not one problem. If you do some home work and honestly don't go for the cheapest option (get what you pay for) you will find a great new engine.

 

I'll 2nd checking www.car-part.com . I have found many good deals there, but you many have to look at a bunch of listings and make some calls to find one. A very large selection of jy's from across the country.

 

If you dont hear it run dont bother.