Landrover Freelander Thermostat Problems

[MandyLou29]

Hi Guys. I am a newbie so please go easy on me!! I have a 02 Reg 1.8GS Landrover Freelander. I have recently bought a new (reconditioned) engine for it as the head gasket went for the second time (and has been skimmed numerous times in between). Prior to replacing the engine I was having to top up the water daily and the same thing appeared to be happening after the new engine was put in. We also replaced the thermostat (mod one) when we replaced the engine but turned out this must have been faulty as when dropped in a bucket of boiling water it still didn't open up. This happened with two more after, bizarre coincidence. We replaced it a couple of times and even reverted back to the standard thermostat in the back of the engine but no difference. Head gasket went again within three weeks and I took it back this last week under warranty and had it replaced. They had forgotten to replace the thermostat with the new one I supplied them (Landrover's own standard one that goes in back of engine). So they fitted it as we drove over and when we got there the problem had returned. Long story short, the engine runs perfectly with no thermostat in at all but as soon as a thermostat is put in, be it standard or the modified one, the engine overheats and certain pipes that should get hot stay cold and it gollops water. Does anyone have any suggestions as this car means a lot to me with sentimental value and my mechanics and my Father (who does a lot of the labour for me) are ripping their hair out now and losing sleep over it. I have had the car since new and everything on it has been replaced and is brand new, it is costing me a fortune and everything that goes wrong seems to be a mystery but I really want to solve the problems and keep it. Any suggestions would be greatly appreciated. Thank you.

 

[freelance]

is the core in your rad all furred up

 

[timfreecom]

hi mandylou, do you know if the cooling system was bled of the air in it when the coolent was replaced? tim.

 

[Mantamad]

You say that when the stat is fitted, the engine uses coolant, I am assuming this is not leaking out anywhere and if this is the case, suspect the the HG is not right on the replacement engine allowing coolant into the combustion chamber, either that or the head or a liner is cracked allowing the coolant into the combustion chamber or a liner has dropped slightly and not getting a good seal against the cylinder head.

By keeping the stat out you are not allowing the engine to reach the correct operating temperature so the cooling system will not be pressurized to the same extent therefore there is less likelihood of coolant escaping.

Before condemning the engine, check that the cooling system is bled properly, your radiator is not blocked (as suggested above) your water pump is operating properly (its not unknown for the impeller to slip and not pump coolant) and that your cooling fan is kicking in properly.

 

[MandyLou29]

Hi all and thanks for your responses. I have read them out to my Dad and here's what he told me: The radiator has water running all the way through it so presumably not blocked, the water pump is brand new and operating fine, and the cooling fan is fully functioning. The water is not disappearing now that the thermostat is not fitted. When it disappeared before it seemed to be evaporating out of the cap as it was overheating and then obviously going into the oil when the HG had gone. The head gasket has been replaced twice in the past two weeks, it's just not changed anything when the thermostat is fitted. Apparently when the thermostat is installed, the lower pipe and the lower portion of the rad remain cold and the top extremely hot, with no thermostat the whole rad gets hot. Bizarre. Surely not every thermostat can be faulty (tried three of each type) so there's something amiss when it is actually installed. The one we tried most recent is the original one that fits in the back of the engine and as I said the pipes at the bottom, lower part of engine and lower part of rad remain cold. Thanks again for your suggestions.

 

[Chaser]

When there was a thermostat fitted was it definitely installed the correct way around??

 

[MandyLou29]

Hi chaser, thanks for your suggestion, yes that was checked and it was right way round. Land Rover are so knowledgeable (not!) that they insisted it can only be fitted one way! We knew that wasn't right so found help elsewhere and yes it was fitted correctly.

 

[Chaser]

Ok. Seems to me if a thermostat won't open then there is no heat getting to it which must point to no circulation to it's spring side. Air lock or collapsed, kinked or blocked hose??

 

[MandyLou29]

We have checked all the hoses and the whole system has been bled many times to sort out any air locks. Still a mystery.

 

[Chaser]

So with the vehicle stationary, if you run the engine with the expansion cap off does it expel all the coolant before the stat opens?

 

[MandyLou29]

We haven't trialled it that way but yes we understand it would as the stat doesn't appear to open at all. Tried Q/Hazel and genuine landrover stat.

 

[Chaser]

Well i would try bleeding while running with the exp tank cap off allowing it to vent trapped air that way.

For the stat to open it relies on coolant flow through a bypass circuit, the IRD cooler and heater matrix. I still think your problem lies there if coolant is ejected before the stat opens, provided the head gasket and cylinder liners have previously been ruled out.

 

[MandyLou29]

Just checked with my Dad and the other mechanic and apparently that has been done and it's been bled and bled and bled . . . it's a nightmare.

Really want to keep the car and get it running right but everything is a mystery and I am being advised to get rid as we can't find solutions but I really want to keep it.

Thanks again for your help and suggestions.

 

[freelance]

can they try bypassing the ird cooler, and why don't they fit thermostat but drill around the outside so some coolant is always circulating, and one does have to question the waterpump in all this

 

[Northern Irelander]

What stat have you in place at present, was the blanking ring fitted with the Pressure relief Thermostat (PRT)

A cooler bottom hose sounds fine to me, its the numerous hgf, has the head been over skimmed??? 0.2mm is the max.


What temperature does the temp guage sit at when warm?


PS block text is hard to read

 

[Chaser]

Just checked with my Dad and the other mechanic and apparently that has been done and it's been bled and bled and bled . . . it's a nightmare.

Really want to keep the car and get it running right but everything is a mystery and I am being advised to get rid as we can't find solutions but I really want to keep it.

Thanks again for your help and suggestions.

If they are 100% certain that the system is completely purged of air and there are no restrictions to circulation then the stat will open due to contact with warm coolant. So that only leaves a problem with the replacement engine if the coolant is ejected before that happens. Recommend you having a sniffer test carried out for the presence of exhaust gasses in the cooling system to help the diagnosis.

 

[MandyLou29]

Hi Freelance, thanks for your comments, I'll pass them on and see what they say.

Northern Irelander, I don't have any thermostat in at the minute I am running it without as the problems occur as soon as one goes in. When it's not fitted the temp gauge stays at about quarter mark going up to half max but when fitted it seems to stay at half all the time and when it's been really bad it flies up to the top and straight back down but as I said the engine has been replaced twice since then. The HG wasn't skimmed this time it's al brand new. I will ask the question about the blanking ring.

Chaser, thanks again for your comments, I will pass that last suggestion on.

Thanks all

 

[WSLR]

You should always change the coolant pump when replacing a K Series engine or doing the head gasket.

 

[MandyLou29]

The water pump was replaced when the engine was changed, it is brand new.

 

[Northern Irelander]

Hi Freelance, thanks for your comments, I'll pass them on and see what they say.

Northern Irelander, I don't have any thermostat in at the minute I am running it without as the problems occur as soon as one goes in. When it's not fitted the temp gauge stays at about quarter mark going up to half max but when fitted it seems to stay at half all the time and when it's been really bad it flies up to the top and straight back down but as I said the engine has been replaced twice since then. The HG wasn't skimmed this time it's al brand new. I will ask the question about the blanking ring.

Chaser, thanks again for your comments, I will pass that last suggestion on.

Thanks all

When the stat is removed, the engine should over cool. It will warm up very slowly, but when you drive it and cool air starts to move over the radiator, the temp gauge plummets to the bottom.

There is a blockage or serious low flow in the coolant system, check the rad by running a hospipe from the top inlet and let it drain out the bottom. the water should easily run through to the lower outlet when the tap is on full!

The stat ring should be fitted when the PRT is installed, its basically an old stat with the centre part removed, you could easily make one out of an old stat.