I see maybe a little greyish smoke when I blip the throttle but it could also be the BG 44K I added to the fuel tank. I know when I first got the Disco she was burning some oil because the smoke was blueish, but lately now it's just the light greyish smoke I mentioned under throttle. Does anyone have experience with Bars Copper Head Gasket sealant?

 

IMHO, and you may not like it, but ANY "mechanic/head gasket fix" in a can is a TOTAL waste of money. Only way to fix a head gasket problem is with a new and properly installed head gasket. If you plan to keep this truck, take the time to determine if you need a head gasket and then save your money to do the repair right once the 1st time.

 

yeah like over rover said fix a head gasket in a can usually doesn't work. But hey for a small leak you never know. If it's not smoking too bad it's probably not a bad leak or a leak at all. If you think it might be a head gasket issue, you might want to do a pressure test. If the test is positive you might want to consider a head gasket kit. However for the overheat problem I would suspect thermo which you already changed so we can eliminate that. Gunked up radiator which you said you flushed. Viscous fan clutch, electronic fan, or leak in hoses or coolant container.

 

If you are consuming coolant I'd agree with "ihscouts" and suspect a blown head gasket. No sense putting any more money into the truck until you have it pressure tested.

 

I have to study a lot, so it's hard to put in time to diagnose the problem with my Disco, especially when the truck is at my old man's place (I really can't wait for Winter Break). I'm going to try to take out the "1 "and "7" plugs tomorrow to see if they're steam cleaned. Please bear with me guys, my apologies for the slow progress and asking so many questions.

As of yesterday I think we can at least confirm it's a head gasket leak but very minimal at that. The coolant was only down about 1/4 cup. I think the problem is slowly getting worse because I wasn't losing coolant before. The exhaust does smell somewhat sweet and when I accelerate I do see a white-grayish smoke screen but very light, it almost looks like condensation from the exhaust.

My only true concern is not the head gasket leak but the fact that the engine could have a crack in the block. I honestly cannot afford to do a complete engine rebuild or purchase a short-block. That being said, I want to ask if there is any way to determine if there is a cracked block without having to do a pressure test with the heads off? It would truly suck if I had the heads off and find a crack in the block. I was looking at XJ Cherokees when I decided to purchase my Disco and I'm trying to decide if I should just cut my losses and sell the truck and get the XJ. I wish I knew then what I know now (cliche). The Disco is much sexier and meaner looking than the Cherokees, and I love the twin sun-roofs and AWD. The 4.0 I-6 engines on those Cherokes are indestructible from what I've read. There is no comparison though, I like the Disco a lot better (might have purchased the right vehicle at the wrong time in my life). Let me know what you guys suggest.

 

Yeah for sure, funny story I looked at a 97 grand Cherokee before commuting to a disco. Definetly worth it though. I wouldnt jump to the worst conclusion of a cracked block just yet though. From what I hear the symptoms are minimal. Worst care you could purchase a used block from a junkyard or something. Anyway the coolant consumption could be air releasing from your recent coolant, change, and the smoke could be from condensation. However if you do suspect a blown gasket do a pressure test. If positive add sealer, and test a couple weeks later, if positive consider replacing head gaskets. If you do then you could do a leak down test to test block.

 

Lol, mr4x4 its just frustrating that I didn't catch this overheating problem when I purchased the truck. The coolant was clean and full, and the oil was black but not milky or brown in color.

 

Here are the pictures of the "1" and "7" plugs. I could not get to the "2" and "8" plugs because I would need a ratchet extension. Let me know if you guys need to see the "2" and "7". I just realized I should have taken out spark plug "3" to compare (do'h). I'm sure the plugs look gunky from the Gumout, BG 44K, and the decarb I did on the engine. I also did a Rotella T4 15w-40 oil change today with a Motorcraft FL-1A large capacity oil filter. It helped somewhat with the ticking.

 

Hmm interesting, plugs look oily if anything.
might want to make sure the pcv valve is still there and hasn't been replaced by a hose. Have you checked your viscous fan resistance, and the electric fans. And is oil still mixing with coolant?

 

Where is the PCV valve you're referring to? I only know of 2 pcv lines. One is on the driver's side valve cover that goes to the throttle body and the other one is on the passenger side that hooks up to the intake manifold, if I remember correctly. There are also two vacuum hoses, one on each side of the intake manifold cover. The viscous fan seems ok, I guess. The fan does not free wheel when I spin it while hot (quarter to maybe half a turn). The overflow and radiator bleed screw coolant looks bright green, no traces of oil. I haven't checked the electric fans because I've had the ac off the whole time the truck runs. Do they turn on as well when the engine is hot? I thought they were only there to cool off the condenser. Thanks mr4x4