I'm not a car guy so I'm trying to get a sense for the validity of "Yah, you're going to need to replace the whole longblock" without a full diagnosis.

Partial diagnosis received:

"Thermostat cracked and all fluid drained out causing overheat.
Car turns over without compression.

Remedy: Replace the engine.

I'm getting a second opinion from a shop that works on LR's but my question to the group is - >"Before the catastrophic failure, I think the car ran max of 10 minutes at ~ 30 mph and ~ 1 minute at ~ 40-60 mph before alarms sounded and it shut down. Is that a scenario that would typically lead to requiring a full engine replacement, or perhaps lesser incremental failures?"

I understand that I'm asking people to spitball, and I'm not going to lawyer up about answers; I just don't have the experience to spitball on my own. Help appreciated.


  • Welcome to Motor Vehicle Maintenance & Repair! Commented Apr 13, 2023 at 0:37
  • Did you drive it for some distance with the "Hot" light lit, or with the temp gage pegged? Commented Apr 15, 2023 at 9:20

1 Answer 1


Provided what you describe is accurate and the engine did run for that amount of time/distance without coolant, then the diagnosis is plausible.

There are any number of things that may have happened inside the engine to cause no compression at this point. Valves may be burned, cylinder walls scored, piston rings damaged. Another common problem with overheated engines is a warped block or cylinder head which now leaks to the point of being unable to maintain compression.

So the proposed remedy of an engine replacement is quite possible, even likely.

But if you have doubts about the diagnosis, you can also take it to another mechanic who may have a different take on the problem.

  • It's possible we drove longer than 10 seconds in a catastrophic state, and the alarms only signaled at the end. I had the motor evaluated: the head gasket was blown, the head was warped, the rings were incinerated and there were grooves/gouges from piston slap on 5 pistons. So I had to replace the motor. You were pretty much spot-on. Thank you, and apologies for the late reply! cr.
    – ChrisR
    Commented May 23, 2023 at 0:14

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