How to tell if a 4.0 has been rebuilt

[PhdNPrerunners]

I just picked up my 96 4.0 4x4 5spd for 900. The lady I got it from said that it had 55k miles on the rebuilt motor and tranny but she didnt have proof cause the previous owner lost the papers. It did manage to make it 1700 mile trip from California to Texas and averaged 21 mpg the whole time. Is there anyway I can tell if the motor has been rebuilt? The odometer has 281k miles on it so I just want to see if she was telling the truth or not. Thanks guys

 

[BRUTUS_T_HOG]

well it depends on who rebuilt it. sometimes there will be a sticker on the block or heads with the rebuilding company's name. otherwise you'll have lead slugs in a few core plugs that indicate if the engine has ever been overheated (to protect them from warranty fraud)

 

[Ranger44]

I agree. Look for the slugs on the freeze plugs.

Other than that look for signs the engine has been out. fresh paint? Look clean?etc.

 

[Frank The Tank]

281k......... and your getting better mpg than me at a freshly rolled over 60k.

You allready bought it..... I'd check the basics, and hope for the best after that. If it blows up in 200k miles...... I'd say you got ripped off!!!!

Frank

 

[pxbacher]

Check the motor mounts? If they were in there and did a thorough job, I'd think they might have replaced them.

-Pete

 

[BeaterMan]

i had the same issue with my 2.8L. PO told me that the engine had been replaced/rebuilt years before and that it only had roughly 30K or something like that but had zero paperwork to prove that. The engine was very clean though and burned no oil ect. I decided to do a compression test and it was at the max that it could be so i kinda figured that it "might" have been newer but still can only go off what the PO said.

 

[out cast]

personal experience....
valve cover gaskets... old and cracking... rip off, somewhat flexible and possibly an aftermarket parts manufacturer... rebuilt...