Blown headgasket?

It ran fine the other day when I pulled it into the garage. Then I pulled the leaking gas tank and dropped it off to be repaired. I got that back yesterday and today I re-installed the tank. Before I fired the motor up, I installed a thermostat and refilled the anti-freeze. When I tried to restart it, it just wouldn't start. It backfired through the carb and when it did start it only ran on one cylinder. After checking for spark and checking for gas I pulled the plugs to see what was going on and noticed there didn't seem to be any compression in three of the cylinders. I did a compress test and found three dead cylinders. I pulled the valve cover and that's when I saw the big "oh no", milky looking oil. I checked the dip stick and the same thing in the oil pan. Two intake valves were way out of adjustment, so I adjusted them, but it didn't improve the compression. How could it go from running so nice five days ago to this? Maybe the valve adjustment was already this bad, I did hear a little tappet noise but I didn't think it was this bad. I'm hoping it's just a bad head gasket and not a crack somewhere.

Any thoughts you want to share with me?

 

A couple dead cylinders would be hard to miss.....
I'd look real close at the two intake rocker arms that were way out of adjustment to make sure they aren't bent; maybe the push rods as well.
Maybe water had leaked into those cylinders during the tank repair.
water doesn't compress.....

 

Well, I'm going to pull the head today and see what's going on. I will also inspect the rocker arms and hopefully see why the valve adjustment was so far out of spec. Pictures will be coming.

 

Moderators, I hope this is ok, but I started this topic on a thread I had in the build section, but thought the topic now was more suited for this section, so I copied it to here.
Copied from the other thread:

Here's some other thoughts about this motor and jeep overall. I noticed a week or so ago that there were exhaust brackets for dual exhaust pipes. You don't see dual exhaust for four cylinder motors, least not in these older jeeps.
I also noticed the head painted a different color than the block, which didn't mean much to me then like it does now.
I think it's possible that this jeep had a V6 in it and some previous owner pulled the V6 and slapped together this four banger to sell it. Maybe they didn't bother to put a new head gasket in when putting the head back on. Also notice only two out four bolts in the water pump a week ago.
If luck is with me, maybe I can fix this without having to do a complete rebuild.

 

Also, this jeep originally came from South Dakota. The guy I bought it from purchased the jeep in '92. It would be cool if the original owner from SD was a member here and could give me some history. Very slim chance of that I would say.

 

whats your vin number check the vin thread and see what originally came in your jeep for an engine i can remember off the top of my head what letter or the place that tells you

 

assuming it is the 55 you are talking about the serial number should be this The prefix consisted of a five digit code, followed on Special models (only) with a hyphen and and two digits.First three digits: chassis / body
54: Wagon chassis
540: Special on Wagon Chassis
541: Wagon
542: Delivery
544: Wagon chassis w/ flat-faced cowl
545: Wagon chassis w/ cowl & windshield
546: Wagon chassis, stripped
Fourth digit: Engine
2: F-head six cyl.
4: four cyl.
6: L-head six cyl.
7: OHC six cyl.
Fifth digit: power train
7: 2x4
8: 4x4
Sixth & seventh digits: Specials
-03: Ambulance
-04: Ambulance
-06: Cargo/personnel carrier
-07: Rail truck (Wagon?)( commonly called "Hi-Railer")
-14 Traveller

 

I checked the VIN number and that checks out with the VIN data. My engine has a number on it and I can't tell what it breaks down to.

Engine number: 4FR155351

Anyone know if this matches up to any code break down?

 

The latest update on what I found. It wasn't a blown head gasket, it was two stuck intake valves, possible three stuck valves. I didn't have a valvespring compressor so I dropped the head off at a local shop. The shop owner is especially good on older cars and motors.
Today I stopped by the shop to see what was going on and Al (shop owner) showed me some interesting information.
Someone had installed some type of brass guides that Al had never seen in these motors. Two of the guides were pulled out. He said they were never intended for the motor, they didn't even reach the full depth of the valve guide hole.
I stopped by our only parts store, a Napa Auto and ordered a new set of intake valves with guides.

Here's a couple pictures of the head and engine deck.




Too bad the lighting wasn't better and my cell phone doesn't take better pictures.

It looks like another week for waiting on parts.