2000 P38 – Expansion Tank Crack

[CaptainTeebs]

I recently bought a 2000 P38 with 67K miles and fell in love with it instantly. I have no mechanical training, but I wanted to do everything I could to learn and take good care of the vehicle. I had it checked by a separate Land Rover specialist who replaced a few worn-out parts and gave it a clean bill of health. I bought a Nanocom and began to try to familiarize myself with all of that. The point is, I want to spend the time and money to take great care of this relatively low mileage Range Rover.

Even so, the expansion tank cracked within a week and began spewing coolant all over the freeway. I pulled over and towed it to a local shop that works on Land Rovers regularly. I know that a blown head gasket is at the top of the list of potential causes, but I'd like to be quite sure that is the culprit before shelling out for a big ticket repair job. The problem is that I don't have a mechanic I inherently trust for this vehicle yet, and I don't have the expertise to evaluate whatever diagnosis the mechanic gives me. 

When I talk to the mechanic in the next day or two, I'd like to be a little more prepared than I currently am (which is not at all). What are some questions I should ask? What parts of the vehicle should I ask him to show me so I can see / photograph them for myself? What are some alternative causes to rule out? What's a reasonable price for head gasket repair / replace (I'm in Los Angeles)?

Thanks! 

[Escape]

That's tough luck...

Seeing you're in the US, I'm guessing it's a 4.0 or 4.6 V8?

First off, are you sure the tank is cracked and it's not the pressure cap releasing? That will still point to a problem, possibly even head gasket failure, but could be an easier fix as well. To split the tank it would probably have to be exposed to excessive pressure for some time. But that doesn't necessarily mean the problem is still present, so could still be as easy as replacing the tank.

- what was the temperature reading before the coolant spewed out? Steady and normal, or rising?
- are you sure the coolant level was OK?

There are a few simple checks you can do if you get the engine running again:
- check for pressure in the various coolant hoses (the big one at the top of the radiator is an easy one to check), they will get harder as temperature rises but should not feel like they're about to burst
- check for bubbles in the expansion tank
- check for traces of exhaust gases in the expansion tank

It's a bit of a shame the car is already at a mechanic, and one you don't fully trust it seems. I'd try to refill (after replacing the tank if it is indeed cracked) and recreate the problem, under more controlled circumstances.

Replacing the head gaskets isn't that difficult. It's one of the first big jobs I did on a Land Rover. So don't rule it out, you only need basic tools and willingness to learn and try. 😉

Filip

[CaptainTeebs]

Thanks Fiilp! Yeah its the 4.0 V8.

Temp was totally fine before the leak began, steady and normal. Coolant had been filled by a Land Rover specialist less than a week before. I've attached a photo of the leak in case you wanted to see.

Happy to say I've had a good experience with the mechanic! He's found nothing wrong with the engine when he tests it, and so it may just be old cracked plastic. We'll replace the tank and see if the issue reoccurs.

Thanks for the encouragement! I'd like to use this vehicle learn, project by project, but it can be a bit daunting for a novice. Great to have found this community!

Jefferson

[elbekko]

Yeah, that looks more like an age-related failure. Living in a hot climate probably doesn't help with that.