I picked up my '02 Disco (90k miles) a couple weeks ago from a private seller. The headgaskets had been replaced in it a few months prior so I felt pretty good about getting it. Well I think either the job was done wrong or there is something else wrong. I do not think the PO was trying to get one over on me as when I told him I think the head gasket is bad he said he would buy all the parts necessary for me replace it. Here is what I"m looking at

Symptoms:
-Sometimes after sitting it misfires (4/6 or 5/7 for the first 30-60 seconds (coolant leaking into chamber overnight?)
-Waterfall noise
-No coolant in resevoir this morning, pull cap and air rushes out and it fills back up (sat overnight in the driveway so completely cold)
-Coolant loss, not at large amounts, but about a quart every tank/tank half
-Stark white plug on #6
-Slight tick to engine. Seems pretty constant, sounds like a lifter but doesn't change with RPM or sometimes goes away when I raise the rpms. Always there regardless of temp. Maybe exhaust gases passing through the headgasket?
-I do want to note that the coolant warms up and then stays at the 1/2 mark on the guage and never rises past that
-Tried the GM Pellets at the advice of his mechanic

What's been done:
-Prior owner replaced headgasket, wires, plugs. I do not believe the heads were machined/checked as his mechanic said there "were no signs of overheating"
-I regapped plugs because the gaps were all off by .05 to .1
-Compression test; came out to 150 or 155 on all cylinders
-Tried to bleed the coolant system with no luck
-Filled resevoir from half full twice in the last 800-900 miles

I still want to do a leak down test, but I'm 99.9999% sure the heads are going to need to come off. What I am looking for though is how do I know if a sleeve has dropped when I pull them or does it sound like I just have a bad headgasket? The cylinder heads are going to go to a machine shop so they will be checked/resurfaced.

 

Why cant you bleed the system? is there a reason?
The correct method is listed on the same page a few post down.

Once that is done you can pressure test the system and see where the coolant is going.
If you think it is leaking into the cylinders rent or borrow a bore scope after pressurizing the system pull the plugs and see if the bores have coolant in them.

 

Brandon, if you want some help with this issue, PM me your number and I'll be glad to walk you thru what to do and look for.
Yes, the heads will have to come off, yes you could do a coolant pressure test, but you already know it is leaking.
Did the PO say the engine over headed before?

 

Mike I did ask him and he said that he never saw it overheat and the mechanic said that there were "no signs" of overheating and that was the basis on making the decision for the heads not being gone over.

I haven't asked, and at the risk of being an idiot, I am assuming that they were originally changed for leaking externally. When I told him that the coolant was IMO leaking into the combustion chamber he seemed suprised like it had not been doing that before.

Looks like I'll just order the HG set from British Pacific today or tomorrow and start tearing it down.

I'll PM you my number. I know I'm new on the forums, but in the research I've done, I've seen you offer help to a bunch of people. So thank you ahead of time for myself and just in general for all the help you have offered on this forum.

 

Hold on ordering the gaskets and bolts, there is a better place to go for good UK parts for less.

 

Thanks for all the insight Mike, it is much appreciated.

 

Just want to follow up with this thread in case anyone ends up here when searching for symptoms.

There is coolant in the 4 and 6 cylinders on the passenger side. *Headgasket looks brand new (PO said it was replaced in Feb). *So either the dude that did it in Feb torqued it wrong or the head is warped orcracked. *We'll find out when they go to the machine shop I suppose.

The one question I do have is the #8 sleeve I can catch with my fingernail... does that mean it's slipped? The head doesn't have an imprint from it smacking it and that cylinder seems fine? Maybe that's why 4 and 6 weren't sealed? I do know that all the head bolts took effort to get out except for the passenger side one next to the firewall.









Compared to the good side



Here's a not so interesting time lapse of tearing it down. I'm gonna say it took me 5-6 hours.

 

Good job on the pictures.
One of the heads was machined already. You can see the machining pattern on it.
If that head is warped, it has to be replaced. If you machine it again, you may increase your compression too far up.
Middle cylinders look affected as you noted.
Best to post pictures of the liner you suspect.

My guess: Head is warped. Was not machined correctly
or
The cylinder head was not torqued correctly.

Do you know if the PO did it him/herself?

Or an Indy shop did it?
How many miles on it?

 

The prior owner had the repair done at an Indy shop. He said the heads were not touched. I see what you are saying about the machining marks. They exist on my block as well..... wonder what's up. Can a machine shop tell how much has already been removed?

Here's a pic of the cylinder I can feel it on. I only can slightly catch my nail on the portion at the very back.

 

Well got the heads back from the machine shop. Had the pass side one pressure tested and had both of them milled. They only took 5 thousandths off so they weren't off much at all.

I did however start to think about this problem more.

1. The head pressure tested good.
2. There is gunk in #4 and #6 and equally as much thick sludge in the very bottom of the intake manifold. I got some on my hand and definately smells like coolant.
3. I'm loosing coolant and air pressure was building in the coolant system.
4. Head gasket looked fine.

The only coolant ports I could find between the head and manifold were on the back side of the block. The coolant would need to travel across 2 and 3 cylinders to make it that far. I doubt it would be the block because here is no coolant in my oil. I really don't think its a sleeve. They are flush with theblock and I've turned the motor over with the heads off with my finger on the sleeves. They don't move at all. There are also no indications of a moving sleeve marking the head either. Additonally, since I checked all of the valves for leakage, there should be no way for a leak in the engine to make it into the intake anyway, especially considering the cylinder is under vacuum. I doubt it's the PCV oil or a cracked throttle body leaking coolant. Both of those would distribute the problem among all the cylinders I would think. Maybe the lower intake is cracked, but it doesn't appear any coolant passages are in that part of the manifold. It looks like they are only up front.

I'm at a loss. Maybe someone who has worked on these before can share some advice. Have any of you seen a coolant leak that made it to the middle cylinders? Looking for some input before i stick this thing back together and have the same problem. I poured water into the I take and exhaust ports. I didn't find anything out of wack except two exhaust valves on the drivers side head need to be lashed because they weren't sealing. No biggy I'll just drop that off tomorrow at the machine shop.


Here's some pics. This is the two ports that are pretty nasty. It looks like normal PCV system oil, but it's really thick in only these two ports. Like still wet thick. The sludge doesn't make it past the upturn in the runner. The only thing I can notice is that it has a "crusting" that looks like maybe coolant that evaporated running along the gasket, but I'm not sure if that's just left over gasket. Opinions? Is that possible to run from that coolant port along all of those cylinders, effecting the middle two the most?



Other side for comparison: