I bought a 2003 Discovery 2 with a blown head gasket. The gasket blew out of the two inside cylinders on the right bank outward toward the exhaust manifold.

When I pulled the head, all 5 of the head bolts inside the valve cover required a 3 foot breaker bar and serious muscle to break loose. All 5 of the head bolts outside the valve cover (the ones above the exhaust manifold) were removed with a 3/8 ratchet with no breaker bar, and just a small push.

Has anyone ever seen head bolts loosen themselves on this engine? Or did the overheated engine put enough stress on the bolts to stretch them? Or did the previous mechanic forget to torque the bolts?

The blown head gasket was a composite, so I assume it has been fixed once before. Also, the head is clearly warped at almost .004" out of straight.

Thanks,
Keen

 

When I tore apart my parts truck, some of the bolts were no more than finger tight. The rest (sans 2) came off with no more than light pressure on a ratchet. Either the overheat stretches them or the PO of my parts truck 2 owners ago fixed it or had not fixed VERY wrong.

 

How long have you had it?
maybe someone JUST put head gaskets on it?
Sorry just saw your pics.

 

I've had my parts truck about a year or year and a half now. The truck actually seemed really well taken care of (mechanically), but there had been some blow by between the 6 and 8 cylinders for quite some time. There was considerable erosion, probably a 1/4" deep and almost 1/2" wide, right into the block between them and more than that in the head. Scrapped the head ($20 in aluminum!) and the bare block will turn into a glass top table. Front cover was pretty gashed from a broken oil pump too. I think the owner 2 owners ago took really good care of it, but the previous owner had it three months before they decided to drive it with no coolant in the engine and I got it for 1k.

 

I would check the block for damage before going much further, it could be damaged from being run like that.

 

"When I pulled the head, all 5 of the head bolts inside the valve cover required a 3 foot breaker bar and serious muscle to break loose. All 5 of the head bolts outside the valve cover (the ones above the exhaust manifold) were removed with a 3/8 ratchet with no breaker bar, and just a small push."



YEP, I'm experiencing the same thing on my son's '97 disco with the 4.0 V8. There is a pattern to follow per RAVE (which I don't have), I can't imagine that would make much difference in the disassembly? My guide is Engine Refresh (top end) | PaulP38A.com
I have broken 3 sockets on one of the bolts. I can't locate my impact socket set, so bought another one, but now need a bigger breaker bar...

 

remove the bolts from the outside in, the opposite that you torque the head going on.
otherwise you will have so much pressure on the last couple bolts you will have trouble removing them

 

Thanks for the replies. I believe I know what happened to this Rover. I pulled the timing cover to inspect the oil pump (2003 Disco, right?) Turns out the timing cover gasket was blown, and a bunch of coolant poured into the crank case. PO apparently had no idea there was a problem until it over heated, expanded the aluminum head, and stretched the outer head bolts past their yield point, and the gasket blew.

I have taken the head to a proper cylinder head shop, and had it milled. Block is OK, checked for warp and blow by erosion. New gaskets and seals all around. New oil pump gears too. Hours of stinky dirty cleanup and gasket scraping. Yuck.

 

Chadley,
Here is the link to the RAVE manual: land rover service factory manual RAVE download land rover resource, service manual, workshop factory manual, download, rave, vehicles including discovery, series, defender, range rover, freelander, LR3, Handbooks, Catalog, Catalogue, Land Rover Inte
Working on a rover without this is like going into combat with empty magazines!

 

Many people have reported the 'loose head bolt' syndrome, and I'm convinced it's a result of the TTY head bolts stretching during the normal heating and cooling process of the engine, which is exaggerated by the Disco's unusually high thermostat and underhood temps.

I'd suggest you use ARP studs instead of bolts when you rebuild to avoid the same problem later, use a 180 degree thermo, and possibly consider hood vents to bring down underhood temps.