'93 4.0 HO: Chain, or belt?

1993 XJ 4.0L HO
Does this critter have a timing CHAIN or BELT?

When I get to 3K, sometimes 4K, my valve train clatters. Im thinking with 134K on it, it needs a new timing link.

Is it also possible, it needs a head job too? (Not THAT kind of head job...) It did smoke at idle a bit too (used some additive to kill that) so Im pretty sure the valve seals are tired.

The engine has GREAT power, just the clatter concerns me.

Any advice or suggestions would be nice,
Thanx...
Andrew

Chain.

Valvetrain clatter and even a little piston slap is fairly common for the 4.0L; the later models had some enhancements to reduce the noise and vibration somewhat but you're still revving that puppy pretty high.

my '93 sounds a little like a diesel, but it has plenty of gitupngo when i punch it, and she's at 200+K miles. in about '96 or '97 (can't remember which), teflon skirts were added to cut back on piston slap, but there are plenty of folks running original engines with lots of miles, so as long as you do regular maintenance, i don't think you're going to have much trouble.

they do have timing chains, indeed.

MyJeepXJ said:

1993 XJ 4.0L HO
Does this critter have a timing CHAIN or BELT?

When I get to 3K, sometimes 4K, my valve train clatters. Im thinking with 134K on it, it needs a new timing link.

Is it also possible, it needs a head job too? (Not THAT kind of head job...) It did smoke at idle a bit too (used some additive to kill that) so Im pretty sure the valve seals are tired.

The engine has GREAT power, just the clatter concerns me.

Any advice or suggestions would be nice,
Thanx...
Andrew

Click to expand...

As the others said, it has a single timing chain. The chain is very durable and usually lasts beyond 200k miles so yours should still have a lot of life in it yet. Timing chain rattle would be most obvious at very low revs just off idle.
Light ticking from the valvetrain and a little piston slap are normal even on low mileage engines so again it's nothing to fret about.
Smoking at idle and upon deceleration could be oil leaking past worn valve stem oil seals. Not a big job to replace.

Thanx for all the help guys! Thanx very much!

I was a little concerned for a while. At idel, you dont hear it inside, but outside it sounds a bit like a Singer sewing machine. Doah! And then the train clatter at 3K rpm (Sometimes you GOTTA pull out into traffic with a lot of skinny pedel!), I was wanting to check on that.

The stem seals, is this something that can be done with the head on? Im thinking not... but never did anything such as this. I have replaced push rods and adjusted preload on the rockers (On a 4.3L), and I didnt break the engine. Doah! Or, would it benefit to just pull the head and have it redone? (seals, seats, cleaned, etc.. etc..)?

Andrew

MyJeepXJ said:

The stem seals, is this something that can be done with the head on? Im thinking not... but never did anything such as this.

Click to expand...

Every time I've done springs/seals with the head on the car I've either stuffed the chamber with string to hold the valve up, or used an adapter and pumped compressed air into the chamber to hold the valve up. This was in a small engine bay with a 350, so I'd imagine it'd be a little bit eaiesr on a 4.0L.