'93 4.0L Replaced Seized Alternator, but now engine lumbers

[ElRayathon]

Coming home a few days ago while driving about 65-70 on the interstate when the engine started squealing and then started to lose power, so I got off to the side of the road ASAP and shut off the engine. It did sound like it was about to stall as I shut off the engine.

As I'm shutting the engine off, it did overheat and opening the hood I saw boiling coolants in the overflow and what looked like steam from under the valve cover (but that could just have been coolant sprayed all over the inside of the engine compartment.

It turned out that my alternator had seized. Also, about a week before, my temperature gauge stopped working and the thermostat and water pump were original, so I replaced:
alternator, Thermostat, thermostat housing, temperature sensor, water pump & serpentine belt,all at the same time.

Once I got everything back together, the Jeep was hard to start, and when it did, the engine was shaking badly and sounded like it was lumbering and about to stall.

I'm pretty stumped as to what else could have broken to cause these symptoms.

Ray

[4.3LXJ]

By lumbering, could you possibly mean misses and runs rough?

[ElRayathon]

By lumbering, could you possibly mean misses and runs rough?

It's running rough and the engine shakes pretty bad. It doesn't sound like the times it's miss-fired in the past (almost like a pause); it sounds uneven, like it's on the verge of stalling. What would a misfiring cylinder sound like?

One suggestion I got was to let it run and remove one spark plug wire at a time and see if it gets worse or stays the same.

Ray

[4.3LXJ]

A shaking engine usually means a miss. And yes, let it run and pull one plug wire at a time and when it doesn't make any changes, that is the one that misses. Better be checking your oil, and you might want to have your coolant checked for exhaust gasses.

[ElRayathon]

... Better be checking your oil, and you might want to have your coolant checked for exhaust gasses.

Too late. I did a "While I'm at it" oil change and the coolant is already (mostly) gone because of the overheating and the pump change. The oil was regular needs to be changed black.

Ray

[bigjim350]

Too late. I did a "While I'm at it" oil change and the coolant is already (mostly) gone because of the overheating and the pump change. The oil was regular needs to be changed black.

Ray

He meant to check it now for signs of a blown head gasket or cracked head caused by the overheating. The rough running could mean your getting water in a cylinder

[4.3LXJ]

I didn't want to cry doom on this, but yes that is what we need to determine. Might just be a head gasket though

[ElRayathon]

Update.:

This morning I verified all the vacuum lines were connected, nothing broken, etc. and checked that all the spark plug wires and coil lead were seated well.

I then started-up the engine and let it run for a bit. It was rough at idle, but smoothed out to how it normally drives at RPMs over ~1000. It would still run rough when I took my foot off the accelerator. So I took it for a test drive and it drove as it has for the past few years, except that it stalled when I took my foot off the accelerator at stop signs. When starting after the first stall, there was one big puff of white smoke after I restarted the engine, but after that one time, there wasn't any more. I had to restart the engine twice to get back to the house. Total drive time less than 10 mins.

When I got it home, I checked the "coolant" (right now plain water + cooling system flush) and there was just a little oil-rainbows on top -- very little apparent oil. I don't know if that's the cleaner doing its job or fresh oil from a leaky head gasket. I also checked the oil and there was some stuff on the end of the dipstick that looked like heavy cream. The oil was changed yesterday afternoon.

[msmoorenburg]

if it looks like fine wet sawdust you have a blown headgasket


oil from blown headgasket
http://1.bp.blogspot.com/-KzhLGA4ZOTo/TlPNy6zShrI/AAAAAAAAAJo/vDjrbnTLybQ/s1600/headgasket001.jpg

[4.3LXJ]

Raymond, I hate to be the bearer of bad news, but it sounds like you have a blown head gasket. It is not the end of the world, but it will need to be replaced

[ElRayathon]

if it looks like fine wet sawdust you have a blown head gasket ... oil from blown head gasket ...

Yup. That's what it looks like at the tip of the dipstick.

The other thing that should have given it away this morning was that even cool, the cooling system was under pressure this morning and when I opened the radiator cap to see if there was any oil in there before I started it up, the water+cleaner bubbled out and over flowed.

Ray