Ok, I am ready to pull the trigger on a '03 (outside the danger zone) or '04 disco. Most that I am looking at are in the 100-125k mileage range. How Can I tell if the head gaskets have been done without service records? It sounds like a very expensive repair and want to know if I need to set some money aside? How often do they blow on these? I would think that I would want one that has been done recently, but most un-educated sellers dont want to mention any motor work done on that mileage, me included until I have read posts on this forum. Now I would welcome all disclosure as long is was done by a qualified mechanic.
Thanks.

 

There's no real solid way... just got to look at various things and try and decide if it's new or old or recent. Look at the gaskets between the heads and the exhaust manifolds where they bolt to the head. If the heads have been done recently the gaskets there should be new. look at the wiring harness ties... most will be undone or re used, may be even zip ties in thier place now where previous work required removing the harness out of the way. Look at the bolts on the engine. Look like they've had a socket or a wrench on them? Kinda hard to tell for sure really. Just understand like anything.. it's a used older vehicle and regardless of wether they've been done... they may have to be done again. A head gasket repair is only as good as the tech or shade tree mechanic who did it. The coolant should look fresh if it was recently done as well. Most people would have put a new thermostat in it as well when doing a head job so that could be looked at. Needs replacing at that mileage either way if it doesnt look fairly new. The biggest tell tell sign will be the exhuast gaskets at the heads.

 

Oh yeah. Doing heads is fairly easy if yo're some what mechanically inclined and have some confidence in your abilities to figure problems out... Will save a lot of $$$

 

Thanks GAR!

 

It is a pretty solid bet that with 120k on the clock the head gaskets have been replaced already.
They usually fail in the 70-80k range.
DYI, $500.
Indie shop, $1500.
Dealer, $3500.

 

Im with Spike, the gaskets have probably been replaced if you didnt notice a coolant leak. If it were me buying the truck, I would look to see if there are any coolant leaks and call it good after that. HGs will be replaced -- that's a fact. I would just make sure the truck is holding coolant and pray that they don't need replacement (again?) soon. Even if they do, it's really not that difficult, just time consuming.