Well I was able to get the heads off easily enough. Cylinders 3 and 6 both had blown the inside of the head gasket right out. The valley pan gasket was bent and cracked in the back left corner. I cant say yet if that fixed the problem until I finish putting the intake back on but as far as I can guess I say that was the culprit.

If I were you Id pull the codes and then do a compression test to see if your issue is the sa,e as mine.

 

So started putting everything back together and it turns out whomever worked on this engine before stripped the head bolts and retapped the block. So now Im at a cross roads do I save the money for a new block or is there some way to salvage my existing one and fit head and exhaust studs.

 

Well it started up and ran well, until it started throwing misfire codes again. I'm at the point where it's going to get a new engine. I'm tired of dealing with possible slipped sleeves and stripped head bolts.

On a positive note I was able to re-tap and mount new head bolts and exhaust studs so good practice with a tap and die there.

 

Sorry to hear about the bad news.

Good luck.

 

the rest of the truck and drive train also have 200K miles on them, you may want to take so time over the holidays and see exactly how much money you are going to have in to it? its going to cost you another $1500 for flanged block.

 

Eh it is what it is. It's can't be worse than my old Audi quattro or Porsche 924. I'm kinda addicted to working on it. There is so much space and everything is big and chunky.

Most of the drive train is new, drive shafts, transmission, transfer case, only the axles aren't new but sometime in the future I would like to get lockers so they will get renovated. I've already re-built the brake system. The chassis is solid with no rust, the body and interior are immaculate. There is some minor wear to the drivers seat and the right rear tail lamp has a small crack in it. All the switches and buttons work and after a good detailing my wife couldn't tell the difference between mine and some of the CPO Discos we were looking at.

So all in all I think it is worth the extra time and effort. Plus with a new engine I won't have to worry about slipped liners and all the other problems.

 

Deuce, I just did a HG on my 2000 Disco II and am having misfires on the three rear cylinders (4,6 and 8) on the passenger side. I replaced the HG (my first time), replaced the plugs, and swapped the wires (they are pretty new, so I wanted to make sure they weren't the problem before I ordered new ones... they weren't the problem). I have a spare set of coils, but I haven't swapped that out due to laziness and the fact that misfires on 4,6 and 8 would be from both coils, not just one.


When I did the HG kit, I noticed 4,6 and 8 cylinders were pretty sooted up. The rest were clean. My disco has 120,000 miles and though this is a replacement engine, the mileage is pretty close to that.


I'm still trying to figure out the misfires. I have a code reader and I am getting a bevy of 02 sensor failures (most likely because of the antifreeze they had to deal with for a couple of months), gear ratio 3, lean... standard stuff... but the 4,6, and 8 misfires are new and fairly consistent on heavy acceleration or when pulling a trailer. I have yet to notice any coolant loss, but it has only been a week.


A couple of your comments caused questions to pop up. I am NOT a mechanic, but, like you, my older cars (rover and a 1983 Mercedes) are labors of love. So, not trying to seem stupid, what is the significance of the valley gasket in your analysis? I have never seen the inside of an engine before a week ago, and to my untrained eye it looked like the valley gasket just functioned to keep dirt off the rods and keep oil from splashing out. I was careful with all of my torques, but I am thinking that portion of the valley gasket did not get tight enough. Second, the valve cover gaskets... I have read that oil can seep out of them to the spark plugs. I don't smell hot oil in my engine compartment. But should I check those? What to look for? Third, I have a compression tester/gauge but I haven't used it yet. Can you tell me how that helped you diagnose your problem? Fourth, did you try a pressure test on the cooling system? I haven't done that yet, either. If so, how did the results of that test help you? I wonder if putting another 5 pounds of torque on the bolts surrounding those cylinders might help if there is a gasket leak. I do have a cheapo torque wrench...


I can turn wrenches and follow instructions, but that doesn't qualify me to figure out what's wrong. Hoping you can shed some light given your recent experience...


Best,


Charlie V

 

There are multiple things that cause a misfire. Most spark or fuel problems can cause misfires. This community always jumps to head gaskets, but really there are many other things to check first. You've changed the plugs, but that still leaves wires and coils, and then also the entire fuel system. Also, if you are seeing sensor codes, they could be contributing to or causing a misfire.

What I would do is clear the other codes, then see if you still have the misfire under load. If you post your codes here, we can try to help you diagnose them.


1. I haven't gotten into the valley of this engine, but the valley pan gasket does what you think it does. A bad VP gasket will just leak, not cause a misfire.

2. If the valve cover gaskets are leaking, you will see a trail oil leaking from them and smell burning oil.

3. A compression tester tells you if the cylinder is holding compression. So it would help you diagnose a bad head gasket, cracked sleeve, damaged piston ring, or bent valve.

DO NOT torque the HG more!!! These blocks are very prone to stripping out bolt holes and you WILL damage your block if you do this.

 

Check that om the head bolts. Last thing I want is a stripped bolt, anywhere.

I cleared the codes this morning and will post the results after some driving today.

I do not smell burning oil or see a trail in the front of the valve covers... Not sure about the back without removing the manifold.

I checked the cylinder compression last night but it was so cold I couldn't get my fingers to work properly and didn't tighten the fitting properly, resulting in very low figures that probably aren't right. In any case, 4 and 6 registered 10 psi lower than all of the others, but, again, it was a poor test. I have a large compressor and can do a leak down test with he right setup; read about that last night.

 

your coils are 2&3 4&7 8&5 and 6&1 so if you are having trouble with 4, 6 & 8 so that would mean you are having problems with three different coils, possible but doughful. I would look for something more in common in those cylinders.