If a D2 is well taken care of, will it need to have the head gaskets done? Are head gasket work just something that happens with all D2s eventually as they get high mileage? Or can you avoid it be taking precautions?

 

Best4x4 has owned several since new and maintained them meticulously, never had to do HG. I have one right now where the owners really cared for it, 140k no hg. I think it is preventable if you are able to keep the engine from overheating.

 

Oh I think they fail without an overheating incident. I've seen it happen to an engine I put every mile on so I know it never overheated. HG at around 120k on the factory replacement 4.6 if I recall correctly.

Otherwise to answer your question I would guess it is a solid 80% probable no matter what you do.

I have no experience with fresh HG's on an inline stat so I'll reserve judgement on that setup.

 

Preventable, no. Prolongable, yes.

Barring a catastrophic event, coolant loss/overheat.

Eventually, age and heat cycles will diminish gasket material.

 

subarus are known for head gasket failures, but hey i have owned a few since 2004, never had a issue, subaru does have this magic blue bottle conditioner they recommend you put in, which i do, never had a leak, keep them cool and maintained and hope for the best

 

IMO, the HG fail is a matter of time. I did not have to do mine until very recently @ 174,500 miles. I know people who did them when their D2 had only 90,000. My car never overheated.

 

I personally think the stretch bolts are part of the issue, they need to be precisely set and any variance is a weak spot. Judging from the ones on my Disco there was a significant difference in the amount of effort to break them loose.

 

We should all defer to The Deputy, who is the professional mechanic (and I mean that sincerely). But "eventually" is an indeterminate term. Eventually applies to (almost?) any component.

If the engine is not overheated, which can warp the heads and lead to head gasket failure, I'd say the head gaskets can last indefinitely, although they may fail eventually.

The head gaskets are very, very narrow at the rear of the heads where the water passages are. Maybe 1/8" to 3/16s"? That's a very small span that is very frequently the location of a head gasket failure.

The precaution is to keep an eagle eye on the coolant temp, and to not allow the engine to run for any sustained period at elevated temps (e.g. above 230°F).

And to answer the subsequent question that was not asked, I see no reason to replace head gaskets proactively.

 

plan to do them. Get ARP studs. and then you won't have to ask this question.....

 

Studs are fine if done properly. I've seen a lot of people ruin blocks by getting the torque wrong! TTY bolts work just follow the proper procedure.