once the engine is cooled ALL the way...sitting for at least 8 hours. Check coolant level in reservoir. If near empty, fill up and repeat process to check again. If low again, you are leaking coolant from somewhere, but that doesn't necessarily mean HG...could also be leaking from heater core etc. (that wouldn't cause the noise though)

You can drive with a minor blown head gasket. However if you run it too low on coolant then you'll end up, overheating and warping the heads even further, causing an even worse HG leak.

Misfire won't create noise like you described.

You said it had "7k in seals and gaskets done" How long ago? Can you post a pic of the $7k bill with parts list?

 

Coolant has been constant as of two days ago when I checked. If it's burning coolant, it's burning it slow. BUT I'll double check today. Sorry for the confusion, it was done 7k miles ago not 7k dollars. Also the head gasket was not one of the gaskets done 7k ago. Don't have the list with me but the most extensive it got was valve cover gaskets. My dad suggested that just that one cylinder may be overheating, not enough to cause a major difference in the thermometer is that possible? I'm going to resurface the heads when I take em off so I'm not SUPER worried if that's an isolated issue.

 

one cyl overheat theory doesn't make sense to me because, heat would move through out the engine block. Perhaps he meant something else by that statement....like if (cyl 5 I think you said is the misfire cyl?) that cylinder is not healthy could it make a temp difference? I would say yes for sure its possible. If you are only using the dash temp guage to monitor temps, then you will not be able to see if the engine is running slightly hot..Like at 212 -220 at all times. Hitting those temps temporarily is ok like under heavy engine loads, towing, idling in traffic in Texas for example.

Back to the misfire: What brand and type plug did you use? Did you inspect the plug wire for fraying or melting? How was it?

If the plug is one of the good ones, and the wire is good, then I would do a compression test on that cyl.
And do you feel you could do a compression test? Its actually really easy.

 

Plug seemed ok minus the oil residue on it. New plug is a bosch. Plug wires look good at first glance but I didn't do more than a half assed inspection. May be worth getting a ground wire to do the screwdriver test? May be worth getting a compression tester like you say as well.

 

Turns out it was a blown head gasket on the side of the engine. My dad's been working his butt off to replace it while I'm at college. I'll post some pics soon. Had the cylinder heads machined as there was some warping. Not surprised considering I put like 2500 miles on it while it was blown.

 

 

I've done it. With your motor off and cold, you simply duct tape your vacuum cleaner to your exhaust pipe at the rear of your Disco and turn on the vacuum.

Then I went all around the truck listening. Sure enough, I found my exhaust leak at my passenger side downpipe because you could plainly hear the vacuum cleaner running there so I put my finger where the hole was located.

I wouldn't have ordinarily seen the spot that leaked, but when I could hear it and put my finger on it it became easy to fix.

 

I never ever would have thought to do anything like this on any car to find an exhaust leak.. So genius!