Hippo is overheating......AGAIN!

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Danielsand

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SoCal
It was good while it lasted. After replacing thermostat, pipes, and the expansion tank, wife didn't have any issues with Hippo for few months. And over the weekend, she barely made it home.

Expansion tank is getting over pressurized, fluid boiling, and steaming. Fans are not coming on. It didn't overheat (didn't let it run when we noticed the problem), and it was brought home on the flatbed.

So what am I looking to replace now? Waterpump? There is no oil in the coolant, and no coolant in the oil (HGF higly unlikely). IF waterpump took a dump, why are fans not coming on? Went from running perfectly on Saturday, to this yesterday.

Imputs/experiences are very welcome!:confused:
 
it could be the sensor for the fans check with a live wire to the fans to by pass anything or even check all wiring if it is a non air con it will have one fan if air con then 2 fans if it only does have one I would think about putting the extra fan in good luck with it
 
My only ever experience of overheating with an engine was a 3.9V8 in a Disco I owned. It was sold by a forecourt as a good car but on our first long run out it overheated. First thing to check was the thermostat to find it didn't have one - so this was obviously not a new problem - and the dealer wasn't interested.

Took it to a Landie specialist and they changed the viscous fan - $500 and didn't fix it. They then checked it more 'thoroughly' and determined both cylinder heads were knackered - so $5,000 this time for new heads and it still didn't fix it. Last time I trusted them, so took it somewhere else. They put a new rad it - forget how much it cost but still didn't fix it. Took it somewhere else and they diagnosed the expansion bottle top. Cheap fix and it held for a while, but went again fairly quickly.

After that I gave up trying to fix it and just got used to steam and water spewing out and filling it up! It overheated for virtually the whole time we owned it which was 7 or 8 years!

From that experience, I'd say if there's no obvious leaks from the rad or hoses, try cheap things to fix overheating, but if they don't sort it, it will probably be cheaper just to ditch the engine and get a replacement - I think you've got a spare engine lying around?

I also gave up on giving my car to garages to fix after that - unless I haven't got time and I tell them what to do.
 
you need to ascertain if it is overheating, or cooling system pressurising , subtle difference in diagnosis i am afraid, but similiar symptom.
 
All good input.

Unfortunatelly, spare engine is not ready yet. Thermostat is new, as is the expansion tank. Bottom rad hose is stone cold, which points to thermostat, but that thing doesn't have more than 4-5 hundred miles on it!

Expansion bottle is definitely over pressurized, but there is no oil/coolant mixing. And the most curious thing is the fans,......ran perfect on Saturday, and DEAD on Sunday.

I didn't have time today to dig into the electrical, but I'll go systematically with powering fans separately from the system (I fully expect them to work this way), and trace the electrical backward to the relays, fuses, and sensors.

Now,.......IF I have some stupid electrical issue (fuse/relay/sensor), would inop fans cause the bottle to overpressurize? More importantly, would inop waterpump cause the same?

I had waterpumps fail on MANY Jeeps, but they did not exibit the same symptoms. I might be the unluckiest SOB on the planet, and I might have a dud of a thermostat, but I doubt it. Especially because I drilled two holes in it, and there should be some flow, even if the thing is stuck closed. And if it is,.........the flow would not be enough to keep the engine at the normal temp range, so it would run hot, which would trigger the fans much sooner than normal, and they are not coming on! That points in two possible directions (if we discount the liners, and complete engine failure)........no circulation due to the inop pump, or electrical failure with fans not coming on line.

IF it's a pump failure,.......fans would still be kicking in (much sooner than normal)!

Am I right in my assesment here?

Sorry about the long post, but I don't have anyone close by to brainstorm like this. And brainstorming with experienced (and caring) people, is what solves 90% of all problems (car related or not).

Thank you.
 
I have seen two Freelander expension tank go bad. And talk to someone who had a bad cap new. I would test the cap to make sure it is keeping pressure and also releasing pressure at 16psi. I would also test the cooling system to make sure there is no leaks.
 
The expansion bottle cap on my Disco was tested and holding the wrong pressure, so a new replacement was bought - and it held a worse pressure than the old one. Took another new one to sort that little problem out.

If water is not circulating, eg stat or pump failure, it would leave your bottom hose cold and possibly not trigger the temp sensor for the fans. The coolant though around the engine would overheat and expand pushing out the expansion tank?
 
it does not matter if you have had the thermostat for a short period they can fail . take it out put it in a pan of water and boil it and see if it opens that the old way of testing
 
you need to ascertain if it is overheating, or cooling system pressurising , subtle difference in diagnosis i am afraid, but similiar symptom.

This^^^^
Also make sure that the pressure cap/ tank is holding the pressure. The V6 runs at 100°C + . The fans don't cut in until 106° C so obviously the pressure must hold to avoid boiling the coolant.
 
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If water is not circulating, eg stat or pump failure, it would leave your bottom hose cold and possibly not trigger the temp sensor for the fans. The coolant though around the engine would overheat and expand pushing out the expansion tank?

This is exactly what's happening. My assesment on the side of the road. Since the stat is new, I discounted that, and suspected the pump. There are no leaks anywhere. Of course I can't see down in the "valley of death", but no smell either until the bottle goes nuts. Lower hose is stone cold, even as the upper is almost melting. The other reason why I suspected the pump, is because I drilled the stat for bypass (I do it on all my vehicles, and it made a BIG difference on my K1200RS is slow CA summer traffic, not so much on Hippo). IF the pump is working (and the stat gets stuck), bypass would not let the temp go into the "danger zone". I could replace the pump (leave the stat alone), and drive the thing. If "all clear", I'm done, if not..........off with the manifold!

I really am not looking forward to do the stat again, but I guess I'll have to rip everything apart in order to verify. As I said before, wife is in love with Hippo, and I have to fix it. To make the things worse, my 06 L322 is down too, due to right front airbag (on bump stops in all four corners).

Now just imagine what expense poor sods that are not able to DIY would be facing!? Spoke with a fella the other day that was selling a NICE Disco (cheap!). Said he needs to get rid of it, because he can't find the shop that,... first wants to work on them (many are refusing), or ....that's reasonable in their rates. Asked me if I can recommend someone. When I told him that I'm working on my own, he looked at me in disbelief.

Ahhh, the joys of owning Land Rovers! :eek:
 
Forgot to ask,........on most cars I wrenched in my life, when the waterpump fails, there is no cabin heat (no circulation through the heater matrix)! How is the Hippo routed? Cause I do have heat in the cabin (plenty of it!).
 
Forgot to ask,........on most cars I wrenched in my life, when the waterpump fails, there is no cabin heat (no circulation through the heater matrix)! How is the Hippo routed? Cause I do have heat in the cabin (plenty of it!).

If you heater is working, that proves that the pump is also working.
I suspect the pressure isn't holding or the thermostat has failed. It is a bypass stat. This means that the bypass valve should open if the engine is revved above 3500 Rpm or thereabouts.
 
If you heater is working, that proves that the pump is also working.
I suspect the pressure isn't holding or the thermostat has failed. It is a bypass stat. This means that the bypass valve should open if the engine is revved above 3500 Rpm or thereabouts.


Thank you. I know you are an authority on V6. I had all the symptoms of failed thermostat present, and I refused to accept that the new thermostat lasted less than 500 miles. It was cheap (most likely Chinese made), but the more expensive ones look the same (and could be also made in China, and identical to the cheapo). So how do you know what are you getting for your money.

Luckily I'm working on it myself. I can only imagine how ****ed off I'd be if I have to pay for the labor all over again.

Since it's a BIG holiday, I haven't done anything on the cars this week. House is full of family, and will be till Monday. Next week I'll gut out Hippo again. Should be easier and faster second time around.

Happy Thanksgiving.
 
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