Geting hot.

Wife's Hippo decided to start with its "fits" again.

Coolant expansion tank is BOILING. I replaced the tank, and the cap from the 'donor' car, and BOTH tanks have radial cracks (they look like surface cracks only) around the neck. I picked the one that looked better of the two, to no dice. Still boiling. There is no water in oil, and no oil in water. Heater works fine, a/c too. Temp gauge does not move from the middle (when cold shows "cold", and when tank is boiling, shows in the middle). No codes, no warnings.

Upper rad hose gets warm quickly, bottom one stays cool for a long time (on tickover), and gets hot (as it should) after the run. No leaks in the thermostat valley, no leaks on any hose connections, and no leaks on the water pump. Coolant circulates (indicates the pump is working). Fans work as they should (can't get them to come on on tickover, but they are on after the run, even after the shutdown for a brief period of time).

I just ordered a new tank and cap, and will try that. If no dice, I'll go for the thermostat replacement. If I'm changing the thermostat, I'll replace the manifold gaskets too. Since the oil is clean (and fresh), I'm discounting HGF.

Question, ......what's the pressure rating of the coolant cap? (I have two sitting on the bench, one is 110, and the other 120) The new one will be coming in with the new tank.

The only thing that changed on the car, was my tank replacement. The original tank had a different cap, and it was steaming a little from the relief valve on the cap, all the time after a longer run. This was annoying to me, so I replaced the tank, and that one has a different cap (not interchangable). Wife went for a longer run (100+F air), and the coolant was ****ing out from under the hood. Temp gauge didn't move!

What am I missing here?

Sounds like a normal k series to me

Dont take it on the motorway, and if you really have too take regular breaks and allow the engine to cool down..

My expansion tank is cracked around the top too....but I dont lose any coolant from it...

the cap is 1 bar on petrol and 1.4 bar on diesel .have you taken the smaill tube of you expansion tank and blown down it to release the jiggle pin ?

teddywood1 said:

the cap is 1 bar on petrol and 1.4 bar on diesel .have you taken the smaill tube of you expansion tank and blown down it to release the jiggle pin ?

Click to expand...

No! Didn't know about that. Pls tell me more.

The caps are marked 110, and 120. AFAIK there should be SOME pressure under cap when up to operating temp, but this is MUCH higher.

I will not feck with it, until the new tank and cap are here. And I forgot to mention, this IS V6 2.5L American version. I will eliminate the possible causes in order (tank, cap, bleed, thermostat), and keep going, hoping I won't get all the way to HGF. IF I do,....well that will have to be done too. I absolutely LOVE a good challenge, and won't quit until sorted out. The only thing I don't like, is that the temp gauge is NOT showing me the increase of the coolant temp! Why they ALL do that? My Jags were the same, ....temp gauge is basically an "idiot light", and by the time it shows ANY temp increase, .......it's too late. Fockers. Just trying to make the most profit, on the top of the initial profit they had when they sold it.

teddywood1 said:

the cap is 1 bar on petrol and 1.4 bar on diesel .have you taken the smaill tube of you expansion tank and blown down it to release the jiggle pin ?

Click to expand...

It's a V6. No jiggle valve is fitted.
All new ratchet pressure caps are 1.2 Bar or 16 psi in old money.
Older non ratchet caps are 1 Bar or 14.5 psi.
The inlet manifold gasket won't cause coolant boiling.
I suspect this fault is a pressure cap issue. Can you run the live data to confirm the thermostat is opening fully. My V6 shows 99 to 101° C at 60 mph.
The thermostat was deliberately set to allow the engine to this hot for emission reasons. Obviously running at boiling point puts the coolant under constant pressure.

Edit.
The dash gauge shows normal with the engine between 75 and 115°C. This was done deliberately to eliminate customer concerns on fluctuations of the gauge under various load conditions

Just a word or warning not to necessarily trust your new bottle/cap. I had a problem on my old V8 Disco where the cap wasn't holding the right pressure. I bought a new cap - and that was even worse! If you're still getting problems, would be worth checking what pressure the cap is holding - or get a workshop to if you haven't got the gear.

Thank you Gentlemen. I had an issue with 06 FFRR, showing me "check coolant level" warning. I replaced the tank, and the cap, and the problem went away (easy fix). The tank caps are very similar (ratcheting type), on RR it's rated 120, and on Hippo 110. I must say that the cap (and tank) rated 110, came off of 'donor' car, and both cars are 2002 vintage, and the similar mileage. Original tank/cap set up on my wife's car was different than the one on the donor (different neck/thread, and no rating written on the cap).

Since 06 RR has the similar cap (different rating), I figured it's an 'upgrade', and I fitted THAT (bare in mind that with the original set up, the cap would whistle a little after the long run, but NOT boil over like I'm experiencing now!).

I think I'll wait till the new tank/cap gets here, replace it, bleed, and go from there.

I got a new aftermarket tank (in Canada parts from the uk are just so expensive. Might not be so bad in the USA). I also found the expension tank cap from a Ford Crown Victoria 2001 fits the 2nd generation of the expension tank on the Freelander. Both Gates and Stant make a cap. I had your exact problem, and in my case the thermostat had failed partially shut. I diagnosed using a wifi obd2 and ios dashcmd on an iphone. I swap for the aluminium housing thermostat made by the user Kaiser in South Africa (rather pricy but well worth it ). Never had any temperature issues since.

zefrench said:

I got a new aftermarket tank (in Canada parts from the uk are just so expensive. Might not be so bad in the USA). I also found the expension tank cap from a Ford Crown Victoria 2001 fits the 2nd generation of the expension tank on the Freelander. Both Gates and Stant make a cap. I had your exact problem, and in my case the thermostat had failed partially shut. I diagnosed using a wifi obd2 and ios dashcmd on an iphone. I swap for the aluminium housing thermostat made by the user Kaiser in South Africa (rather pricy but well worth it ). Never had any temperature issues since.

Click to expand...

Thanx. After much thinking, I came to the conclusion that only two possibilities exist. When the engine was changed, system was not properly bled (it was hissing through the valve of the old cap right away, with minimal loss of coolant due to evaporation), and/or thermostat failed later (over boiling from the cap, significant coolant loss, through the cap). Since the heat works, and the lower hose does get hot (after longer run, but not at idle!), I think thermostat is toast (lower hose should be fully "inflated" and warm at idle, as soon as the operating temp is reached, and at idle it feels cold, and partially deflated). MAYBE, .....improperly bled system, caused the thermostat to fail (obviously it's either partialy closed, or opens too late).

So I ordered the new stat, but not the aluminum one. After I checked with the original owner, I decided that if the original thermostat lasted 96K miles, I'll be fine with OEM, for another 40-50K (that's all wife will ever put on the car). $30USD shipped to my door + $50USD for the tank and cap. Cheap fix, and a nice/entertaining day for me in the garage. I've never had Hippo's thermostat in my hand, so I don't know IF I can drill it (as I do on all my vehicles at the time of change)? Replacement thermostats for MOST American vehicles offer "fail-safe" thermostats that already have predrilled hole. Since I drive British and German vehicles only (except the American truck), I drill them all. And two small holes drilled in the stat on my BMW K1200RS bike, made a WORLD of difference (running much cooler, with fans coming on only in stop and go traffic on the side streets, in 90+F weather). Since in CA we are "spliting lanes", it's not that important on the freeways.

Since the garage is not airconditioned, Hippo repair will have to wait few weeks until the temps go back to 80s (howering around 100F for the next ten days or so).

After I finish it, I'll post the results in this thread.

Thank you all again.

You can't drill the thermostat but you shouldn't need to. The thermostat is a PRT or Pressure Release Thermostat. So get the water circulating all you need do is rev the engine over 3000 rpms. This will open the pressure bypass, supplying cool water to the engine via the bottom hose.
It's quite common for the bottom hose to feel cool to the touch.
Here in the UK, the bottom hose gets about 10° C hotter than the ambient air temperature and no more.

The thermostat is quite entertaining to change. At 96K miles, I expect it will disintegrate, requiring careful removal from the block.
Make sure you have the top hose elbow pipe and straight water pump link pipe as all parts will need replacing.
Some silicone grease will be needed to get the O rings to fit the block without getting damaged.
You may find it easier to remove the front inlet manifold from the head too.

Oh and don't run the engine without coolant, even for a second or head gasket failure will result.
Good luck.

I had the same problem, I bought new expansion tank and cap but still have not solved the problem.
When driving 140 kmh, blow water to cap and the temperature gauge up to red.
I removed the intake manifold and the thermostat on the engine block, intake gasket was fine but o-rings thermostat were damaged.
I replaced the o-rings plus a few washes the cooling system and it seems that I do not have problems, a lot of dirt in the cooling system.
.....and installed this pressure gauge ,works well

tonytherunner said:

I had the same problem, I bought new expansion tank and cap but still have not solved the problem.
When driving 140 kmh, blow water to cap and the temperature gauge up to red.
I removed the intake manifold and the thermostat on the engine block, intake gasket was fine but o-rings thermostat were damaged.
I replaced the o-rings plus a few washes the cooling system and it seems that I do not have problems, a lot of dirt in the cooling system.
.....and installed this pressure gauge ,works well

Click to expand...

Great! The difference is, my in dash temp "gauge" doesn't move. Goes from cold to the middle, and stays there.

Danielsand said:

Great! The difference is, my in dash temp "gauge" doesn't move. Goes from cold to the middle, and stays there.

Click to expand...

The gauge in the middle is showing that the engine is between 75° C and 115°C . Use the live data for accurate temperature measurements.

It's done! What a bear of a job in the barn at 100F temp. Soaking wet, greasy up to my elbows, but Hippo is purrring. New stat, pipes, coolant tank and the cap. No more pressure, no hissing, all good.

Thanks to all who offered the advice. I hope I don't have to do it again any time soon.

Danielsand said:

It's done! What a bear of a job in the barn at 100F temp. Soaking wet, greasy up to my elbows, but Hippo is purrring. New stat, pipes, coolant tank and the cap. No more pressure, no hissing, all good.

Thanks to all who offered the advice. I hope I don't have to do it again any time soon.

Click to expand...

Wait. Hold on a damn minute!
You own and run a ranch/farm. You keep horses, you work the fence, you shoot guns. You are, by most accounts, a proper man. Hell you're even pretty cool for a yank.


But you drive a ####ing gaylander?!?!?! Sorry, what?!

Danielsand said:

It's done! What a bear of a job in the barn at 100F temp. Soaking wet, greasy up to my elbows, but Hippo is purrring. New stat, pipes, coolant tank and the cap. No more pressure, no hissing, all good.

Thanks to all who offered the advice. I hope I don't have to do it again any time soon.

Click to expand...

Good outcome.
I change my V6 thermostats ever 3 years with the coolant. I find it avoids drama's of that nature.

the_wolf said:

Wait. Hold on a damn minute!
You own and run a ranch/farm. You keep horses, you work the fence, you shoot guns. You are, by most accounts, a proper man. Hell you're even pretty cool for a yank.


But you drive a ####ing gaylander?!?!?! Sorry, what?!

Click to expand...

Someone hijacked your account Wolf? Or are you just a ####?

GrumpyGel said:

Someone hijacked your account Wolf? Or are you just a ####?

Click to expand...

God some people have no sense of humour

the_wolf said:

Wait. Hold on a damn minute!
You own and run a ranch/farm. You keep horses, you work the fence, you shoot guns. You are, by most accounts, a proper man. Hell you're even pretty cool for a yank.


But you drive a ####ing gaylander?!?!?! Sorry, what?!

Click to expand...

No Lad, I drive one on the left. Given that I was in the car business for a while, I have a trouble with trusting dealerships, service departments, and the mechanics in general. So I work on every vehicle we own.