Problem with 304

It was beautiful here today, so I dropped a new battery in my jeep, and cranked it, but it never fired. It was getting air and fuel just fine, so I went to check for spark. Pulling the plugs on the driver side, I found oil on the spark plugs. I then noticed that there was oil dripping (not spewing or anything) out of the bottom end of my exhaust manifold on that side (its open). All four plugs on the driver side had oil all over them, almost dripping, and none on the passenger side had oil on them.

So what would cause my oil to enter the combustion chamber? Bad piston rings come to mind, but I don't really think that would be the case for that whole bank of cylinders at once, right? I'm kind of confused here. I disconnected the battery and shut it all down for the night. I figure I'll go have another look tomorrow after someone more knowledgeable than myself tells me what I'm looking for. Thanks in advance, guys.

 

possible blown head gasket
compression test should prove this,
Jay

 

I think a blown head gasket would result in coolant in the cylinders or low or no compression, I think oil on the spark plugs usually goes past the rings or valves, how about a little more history, was the engine running OK before the battery install ? Had it been sitting for a period of time ? A compression test would be helpful to tell if the rings are shot.

 

It had been sitting parked for about 6 months out in the cold with a cover on it prior to about a week ago. It ran decently before that. No coolant in the cylinders that I can tell, but that doesn't mean there isn't any in there. I wasn't looking for it.

Lets say I'm able to find out that its just a head gasket and the piston rings are fine for now. Is a head gasket the sort of job I could do myself? No special equipment involved in that, is there? A torque wrench, maybe, but I can always find a need for more tools

 

Take off the valve cover. Check the drain/return holes in the head for sludge. They may be plugged and combination of bad valve seals let oil in the cylinders (I've seen it happen). Would do a comp test first though. No special tools for head gasket, well a torque wrench. Intake, exhaust, and head gasket.



Got the intake off, might as well change cam and lifters, new chain and gears, new intake and 4bbl carb.

 

Pretty tempting idea on the bottom, Bob. Further testing and diagnostics will have to wait, I have a full schedule from now til Sunday. In the mean time, any other ideas are always welcome.

 

A compression test is a good idea, It will give a good idea of the general condition of the cylinder but if it was running good before storage perhaps just clean or replace the spark plugs and see what happens. could someone have fogged the cylinders with oil to prevent rust while in storage, It's a common procedure and could explain oil on the spark plugs.

 

Sounds like possibly bad valve guides & seals, that will allow oil to leak fron the heads into the cylinders, as well as into the exhaust manifolds.

 

No, it wasn't winterized or anything, and it has/had fresh gas in it, so that isn't an issue....I cranked it over a few times in the last six months, but the old battery sat dead so long that it wouldn't even take a charge. New battery solved that, but now I've got this issue, so its still not going anywhere. I'll try to do a compression test on Sunday and get back to you guys with some results.

If I need the heads rebuilt, what should I expect that to cost? Is THAT something I can do? I'm pretty good with mechanical things, but if there are little tricks to it, then I'd be more comfortable handing it off to a pro. I know you guys aren't from this area, but price shouldn't vary too awful much from here to there.

If its a head gasket, how many man-hours am I looking at if I want to do it myself? I'd go ahead and do both sides while I have it torn down obviously. I'm going to skim through the Chilton's manual to see what they have to say on the subject, but their coverage of the 304 was pretty slim at best if I remember right.

I know how you guys love pictures too, so here are a couple.
The Jeep itself when I first bought it, and where it is now.
http://www.facebook.com/photo.php?pid=31004939&l=0b9e1&id=121200401
http://www.facebook.com/photo.php?pid=31004941&l=29b9b&id=121200401

Picture that includes the oils exit point (nicely marked with paint R) )
http://www.facebook.com/photo.php?pid=31004940&l=850a6&id=121200401


I had a guy walking past come and look at it for a while when I was pulling the plugs. He runs an 84 CJ7 and was envious of mine . Anyway, he asked a question that I couldn't answer (not too hard). The last picture here points out an accessory that I was unfamiliar with. Is it an old AC compressor? The heater doesn't even work in this thing, so I find it hard to believe that it once had AC.
http://www.facebook.com/photo.php?pid=31004942&l=a476c&id=121200401


Anyway, that's all I got for now. As always, questions and comments are more than welcome.

 

If you need the heads worked on, it's best to send them out. This is not something that you can do economically - you'd need too much specialized tooling.

I can do a V8 head gasket in an afternoon, if I didn't get bogged down in the might-as-wells.

The main problem will likely be the exhaust manifold bolts. I'd leave the exhaust manifold attached to the head, and only disconnect the manifold from the pipe. Realize that exhaust manifold bolts sometimes break, and the best way to fix them is to take the head to a shop and have them remove the bolt.

Air injection, aka smog pump. Shoots air into the exhaust manifold to burn any remaining hydrocarbons in the exhaust.

 

Machining the heads is quite a variable process and almost impossible to say in advance what the cost will be, as Tim said it is not feasible to purchase the equipment to do the work yourself. This Is precision machining equipment and is a far cry from the days when shops used to hand lap the valves with a suction cup on a stick and some compound. Even the large shops farm out the machine work.
The reason I say it is almost impossible to say in advance what the cost will be is You can get a simple valve job which includes disassembling the heads, machining the valves and seats and reassembling the heads with new oil seals. Additional work and charges can include replacing damaged valves and springs and machining replacement guides and seats. In addition you may need to check for cracks in the head and resurfacing the heads.
Before taking the heads to a machine shop price rebuilt heads so you know what the max cost would be and go to a reputable machine shop and get an estimate .

I had my 304 heads reworked about 2 years ago. I had the valves and seats machined, had the heads surfaced and believe replaced the intake valves, I also hot tanked the heads as well as the intake and valve covers. I don't believe any seats or guides needed replaced. If I recall correctly it was around $190.

 

Alright, I've got the rest of the afternoon to spend on my jeep. I'm going to run a compression test (which the left bank of cylinders will fail miserably) then plan to either find a bad head gasket, or ship the heads off for rebuilding.

If its just a gasket, I may have it running again by sunset. A couple of questions before I even open up the tool box.....

1. Will a bad head gasket be immediately evident? Should I expect to see some deformation, or cracks or what?

2. How much coolant/antifreeze does the stock setup contain? I'm sure it hasn't been changed out this decade, and I don't know how much to buy.

3. Are there any tricks to the 304 that I should be aware of? The Chilton's manual actually did a decent job, I think, but I know they miss things from time to time. Am I going to get hit in the face with a stream of coolant if I forget something? This will be the first time I've gotten this far into an engine, so there is quite a bit of uncertainty. I've got my camera and plan to document it all pretty thoroughly, but there are always those little 'gotchas' in a project this size. I'm heading out for a compression gauge and some lunch, I'll check back in on the site throughout the day and probably tonight as well. Wish me luck!

 

1. Will a bad head gasket be immediately evident? Should I expect to see some deformation, or cracks or what?
- It should be fairly evident, the gasket will be split / cracked.
Frankly, it doesn't matter, you'll have to replace it anyways once you pull the head. So don't sweat it, just replace it.

2. How much coolant/antifreeze does the stock setup contain? I'm sure it hasn't been changed out this decade, and I don't know how much to buy.
- A single jug of full strength antifreeze is plenty, just mix it 50/50 with distilled water from Walmart.

 

Alright, now I really am puzzled.

Compression test yielded these numbers

1-155 2-132
3-152 4-151
5-150 6-145
7-150 8-150

The passenger bank wasn't the one giving me problems, but has a lot more variation in compression, while the driver side checked out great, when there was a lot of oil in the cylinders........What the heck?

Anyone got any ideas now?

 

Alright, so I know I said it wasn't bad gas, but I decided to check and make sure.....Pulled the fuel line off the intake for my fuel filter, and ran about 20-30 oz of S*** brown gasoline into an empty bottle before the typical color of gas started coming out. Put it all back together, pumped the gas a few times, started her up, LAUGHED A LOT, then drove it around the block for about 15 minutes before parking it. Man has triumphed over machine (for now)

 

Cheap fix after all to get it running. Doesn't explain the oil in the cylinders but it runs. Compression wasn't bad except for 132. Even the 145 is tolerable. 10 to 12 lbs difference isn't bad. Run it for a while and check it wet ad dry and see what happens. With that kind of pressure (145 - 155) I suspect valve seals. That you can do on the vehicle. Need a valve spring tool and about 10 feet of 1/4" rope. New seals and valve cover gaskets. That's all. About $30 worth of parts and tool rental.