2002 disco II - 65K mi.

I have been posting and searching this forum for past few months about my cooling system. Truck runs good but is losing coolant with no apparent leaks( about 4-5 ounces per 100 mi. of use). I have confirmed that there is combustion gas in the coolant. I had decieded to have head gasket changed. Took it to a good rover mechanic. He advised against head gasket replacement because he thinks it has a slipped cylinder sleeve. He discovered signs of coolant on #4 cylinder spark plug. He used a camera to observe top of piston and said it appears too clean. Sign of steam from slipped sleeve or craked head in his opinion. I sought a second opinion and got same answer. Both recommend new engine. Truck runs good other than coolant loss, acassional sticking thermostat and hose blowing off. Finally my questions, is coolant on spark plug a proof positive sign of slipped sleeve or craked head? Is new engine the only solution?

 

Normally the HG leaks coolant at the front and rear cylinders. See pix from a blown gasket, that rectangular channel is the water path way. So coolant in the "middle" cylinders is a bigger issue, it can indicate a cracked block, coolant oozes up between the cylinder wall and the liner, and into the cylinder, where steam cleaning takes place.

You can put a dye in the coolant, run truck, pull plugs and inspect for flecks of the dye.

Now for repairs. If it were just the sleeve, that can be replaced by another type of "lipped" sleeve called a top hat. But the cracked block is a different animal. Many salvage yards near me sell whole engines for like $200, you pull, or pay some one to. You'll almost always have to do HG, maybe more. If it was just a cracked head, you could buy a head for $60 used. But it is the cracked block that your mechanic is talking about.

Now to the bandaid. You have two pros tell you that engine needs replacement. You need some time to find a solution, and let available funds for this build up a little more. There is a product called K-Seal, and there are others on the market. They basically use a liquid chemical sodium silicate for a glass-like bond when exposed to high heat. Some extra stuff is mixed in (copper in the case of K Seal), aluminum flakes, nano fibers, etc., depending on brand. You pour it in the coolant, it seals the crack. Well not always. But in your case you don't seem like you could hurt the truck any. And it may slow it down enough for a few months. Or longer. When used for radiator problems, frequently the thermostat is clogged or the lower part of the radiator is clogged, and overheating gets worse. In your cooling system only has to support 15 - 18 psi, so one would think that a patch on the block, covered by a steel liner, with mucho pressure from the cylinder on the other side of the liner, would be a good place to try. A patch on an external HG leak is a lot harder to hold in... Of course, expansion/contraction may fool with the patch.

If you don't have steam produced at lower temps, you could install an in-line thermostat and run truck at 160F, heat would be weak, mpg somewhat less, but block would not be expanded so far. Hard to figure unless you know that white smoke / coolant loss only happens above a certain engine temp. Most likely it happens at any reasonable temp, and more at higher temps.

 

Thanks for the advice. I have been thinking about trying some type of sealer but was afraid of damage to radiator and thermostat. That doesn't seem that important at this point. I also thought I might just continue what I have been doing; keeping coolant full and bleed air as suggested in the "how to's" on this forum. Logic tells me to sell it and cut my losses but like most of you, I really like the rover. I'm not sure how to approach a new engine. One mechanic says another rover engine will be more of the same. He recommends I find one that has been rebuilt with modified sleeves that won't slip. Where would I find one and how much will it cost? I have some money in emergency savings but don't want do something foolish. I'm not in a hurry because my wife has a nice dependable vehicle and I have a company truck for work. The rover is more of a hobby truck, an expensive hobby!!

 

First, find a new mechanic cause yours is a fool.
Second, never use sealant of any kind in a Disco, you will plug up the veins of the radiator and loose your engine.
You have a typical head gasket failure causing both a coolant leak as well as exhaust leak into the coolant.
Start looking for a new mechanic.

 

It seems that mechanics are reluctant to replace head gaskets on DII because of history of cylinder sleeve and block issues. If these issues are present, would they be obvious during gasket replacement procedure?

 

I re-read your post. I made a mistake, because I need new glasses and did not see the cracked head phrase. You can get a used head for a very modest price if needed. The machine shop charges about $100 to level the head, if warped. So a garden variety HG job may do the trick. Or you can DIY $300 parts, $200 for machine shop (both heads).

However, coolant in the middle cylinders can also be a sign of cracked block, and if that is found, repairs will be higher. As to slipped sleeve, you did not mention any tick, that is also something that can come with a slipping sleeve.

 

We have had posts of seeing coolant oozing between the block and sleeve. But there is an engine block pressure test that runs air pressure up to about 80 PSI inside th block, and you squirt soapy water on parts to look for bubbles. Have to take a lot of things apart to do the test.

You can put dye in the coolant now, run truck, look for flecks of dye on the various spark plugs. Middle ones can be a bigger problem.

From the indy shop viewpoint, they don't want to have the job come back or be disputed with credit card company because of the sleeve issue. And if you asked them to start on an HG job, they take off the top part of the engine, then what? Since it is a hobby truck, perhaps you do the head gaskets. Or find an indy shop that is Rover-ready. Metro Atlanta must have plenty of them.

 

There is a ticking noise. Sounds a lot like an exaust gasket starting to leak. That may be what it is.

 

Well, a tick can be anything from a slipped sleeve to a cracked oil pump, a cracked flex plate, or problems with the SAI system, sticky lifter, etc. And I just recalled that Hartwell is not exactly metro ( I used to commute to Atlanta from Easley, just up the freeway on the other side of the lake ).

 

Hartwell is about hour and half from Atlanta metro. One of the mechanics I took it to is in Atlanta and the other is local. I appreciate all the opinions and enjoy reading this forum. It seems the ball is now in my court and I need to make a decision about what to do.