Troubleshooting coolant vacuum fill failure

What I remember from doing my own procedure was that the hose with the thermostat is amazingly complex and hard to reach to work on it in situ. If I hadn’t first pressure tested the system, I would not have found that one of the clamps I had put on wasn’t seated properly. Vacuum fill wouldn’t have found that, either.

@Rendak,

As folks mentioned - these problems with the coolant system are rather legion with the LR4 (at least the AJ 133 engine I have in my 2010)...and coolant problems appear to be multiplying with newer engine designs (for all vehicles).

It seems engine designs are getting more and more complicated and integrated which puts more stress and strain on all these cooling system parts - causing them to fail. Combined with using all kinds of plastic and rubber parts...that makes these things relatively "unreliable" (i.e. they brake, sometimes at the worst possible times) and something to keep our eyes on. As I noted - I have had quite a few troubles with my cooling system but fortunately nothing catastrophic.

Also, making mistakes is all part of "the adventure" and happens to everyone. So if the hose disconnected for whatever reason, know you are not the only, the first, and certainly won't be the last. It happens to the best of us and here is a pretty funny video of Christian and Vera (from their very popular YouTube Channel LR Time) heading into the Alps for a big test drive of Vera's DISCO 3 after a total rebuild (but not total replacement)...only to have the thing almost overheat because Christian screwed up and forgot to close off a coolant hose clamp- which dumped out all the coolant as they were climbing. Pretty funny (as a learning point) and good news because no one was hurt and the engine was fine - they caught the issue in time.

Just to prove that these things happen - we will see you on the high ground!

Thanks for the kind words, @Land Rover Joe! From one internet stranger to another, I really do appreciate it. And I love LR Time! I haven’t seen this one, but it makes me feel better to know that even Christian makes mistakes.
I’m taking some time away from the LR4 this weekend, but when I get back to it on Tuesday, I’m gonna redo the vacuum fill and pressure test and then start some diagnostics for any signs of overheating. I’m hopeful that because I didn’t get any DTCs at all and because I pulled over and shut off the engine within about 10 seconds from noticing the engine going into limp mode that I didn’t cook the engine. Keep your fingers crossed for me!

Thanks, take your time, and keep us Posted @Rendak !

I will keep my fingers crossed!

As for my build (or extensive service is more appropriate)...engine was buttoned up today and tried to turn it over....only to have continual faults from the brake system which in-turn (I think) shut the whole computer down. So we could manually run the (new) starter motor and charge up the fuel system with the HPFP (by overriding them on the relay board)...we couldn't actually get the engine to run.

I am waiting for two more pistons for my front calipers before finishing the front brake installation / refurb and so the brake system is currently emptied out and there is no pressure anywhere (and the brake lines haven't yet been fully fitted). So the computer must be detecting a major brake malfunction (True!) when going through start-up ("Press the Brake Pedal to Start") and just conking out.

Guess we will have to finish with the brakes first...which gives us the chance to continue cleaning up, painting some corroded parts, and redoing wiring looms.

Good luck again and wish us luck with the next phase (starting engine - hopefully next weekend)!

Having just completed the timing chains, along with replacing the front and rear cross over pipes, water pump, thermostat, radiator and every coolant hose in the engine bay, I can empathize with your situation.

Mine failed the vacuum test and I couldn’t understand why after checking all the connections multiple times. I ended up picking this up and was able to find the cause in a matter of seconds of running it. It also gave me a good reason to upgrade to the brass fitting for the water pump.

Solary Automotive Smoke Machine Leak Detector - https://a.co/d/6zoYOS6

Good luck!

CPalacay said:

Having just completed the timing chains, along with replacing the front and rear cross over pipes, water pump, thermostat, radiator and every coolant hose in the engine bay, I can empathize with your situation.

Mine failed the vacuum test and I couldn’t understand why after checking all the connections multiple times. I ended up picking this up and was able to fine the cause in a matter of seconds of running it. It also gave me a good reason to upgrade to the brass fitting for the water pump.

Solary Automotive Smoke Machine Leak Detector - https://a.co/d/6zoYOS6

Good luck!

Click to expand...

Curious what did you pay for all that work?

Today I got back under the car and connected the radiator hose properly but got another vacuum leak so I put in close to 8 liters of coolant and then hooked up the pressure tester, but this time I am struggling to generate even a few PSI of pressure. No external leaks that I can see either (and no drips or pooling under the car), so like before, I'm worried that the worst has happened and the head gasket is blown. I'm gonna go by Harbor Freight tomorrow and pick up a combustion leak detector kit.

If it turns out that exhaust gases are entering the coolant system, does it make sense to pull the spark plugs and run a borescope to see if coolant is entering the combustion chamber? And are head gasket repairs even worth it on these engines, or am I looking at potentially getting a remanufactured engine?

Really sorry you are having this string of bad luck. Hope things start looking up for you.

Not sure you should run the engine for the exhaust gas test with only 8 liters of coolant in the system (and a massive leak someplace). I’d probably do a compression or leak down test on each cylinder instead.

I suppose the other thing you could try first is running your pressure tester on the coolant system while snooping around with a stethoscope with the cone on it to listen for the hissing of an air leak. If you have a compressor with a large enough reservoir, you can probably get a few minutes of quiet air pressure before the compressor kicks on and makes it hard to hear the leak. If your leak is into a cylinder, you might hear it through the plug hole, but first I’d just try listing around all the coolant pipes.

No idea if it’s worth doing the heads if that’s the problem. I remember reading a mechanic’s post one time saying that the head bolts have a tendency to either strip or get loose after the heads are replaced, resulting in recurrent head gasket problems, so that this persons’ garage wouldn’t even do them anymore (people would return blaming the garage for shoddy work). And, maybe as a result, it seems like people charge really high prices for the work, so it’s a tough question whether it’s worth it.