Driving my 2000 XJ 4.0 with 132k the other day and noticed some steam coming from the radiator. I was in the middle of nowhere and had about 20 miles to get back to civilization so I pretty much had no choice but to drive it. Coolant was slowly spilling out on the ground as well(leak in radiator) Temp gauge was just barely above the halfway mark, I decided if it got any higher I would pull over. Just then started hearing a really fast tapping sound coming from the engine, would get louder and faster if I pushed on the gas. As I was making my way over to the side of the road the engine shut down, temp gauge goes into the red and oil smelling smoke starts pouring out from the engine, steam pouring from the radiator.

I let it cool down, some oil, a few tablespoons, laying on the top of the plastic cover underneath the engine and under the Jeep as well. When I try to turn it over it almost sounds like just the starter is spinning and that's it, crank pulley is moving though.

I don't know too much about engines myself but a buddy of mine said there's a possibility the timing chain might have snapped? Is there a way I can pinpoint the problem? I'm obviously hoping I didn't fry the engine but wanted to get some opinions before I assumed the worst. Thanks

 

If the timing chain snapped it would have died.

Sounds like the motors junk..

 

It died as I was pulling over to the side of the road

 

Pull the valve cover and see if the valves are opening and closing as the motor spins over. No movement=snapped timing chain.

 

Engine sounds like it is blown from overheating.

 

if the timing chain broke the motor would turn over real rough and prob air lock.

 

Pistons would hit the valves

 

Previous owner of my daughter's '86 lost the timing chain at 158K miles, and they did $2707.28 worth of repairs in 2005. I have the receipt.

That included the water pump, oil pump in addition to the head, rods and machine shop charges.

(and that was a relative of the owner!)

 

remove the distributor cap and see if the rotor spins when you crank it over. if it doesn't move, the timing chain is your problem.

but it sounds like you cooked it.

 

x2
it is very unlikely that the chain broke and if it did the valves wont hit the pistons on a 4.0

over heating can cause many other problems
do a compression check first to see if the rings are unseated

 

not on a 4.0

 

If you looking for a quick answer on the timing chain remove the cap and trun over like stated....but i wouldnt tear into the motor if it doesnt spin as i have seen distributor gears get chewed off many timesnext srep go to the valve cover.......IMO you melted the rings........and have no compression to make it combust.......seen that happen many times....

 

Why not?

 

the 4.0 DOES have dish pistons....the look to be around -3cc they are not flattop with valve reliefs...and it should be a non interferance motor..........meaning if its out of time or a valve is hung wide open...it wont hit the piston......

 

its a non interferance motor