V6 Overheating, please look at video

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Ascension

Member
Posts
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Hello,

I thought i'd start a new thread as the old one was under a different heading and that problem was solved thankfully.

So i'm trying to diagnose the ongoing overheating problem on my v6 freelander. Coolant starts to boil in the overflow bottle after about 20 mins idling. I've have already changed the thermostat with no change. Top radiator hose gets hot but bottom hose stays stone cold so logically I think I'm left with either faulty water pump or clogged radiator.

If I understand the cooling system correctly, removing the top hose as shown should give a good flow from the water pump correct?
I suspect the flow shown in the video is insufficient but I wanted to get a more experienced opinion if possible.

Also I have flushed water through the radiator and it's definately not completly clogged up but I guess it still may be the problem.
I was just looking at how to change the water pump, let me tell you I hope that is not the problem!

It actually all looks reasonably straight forward except for the part where you use special tools to lock of the top cam pulleys. Is this part essential or is there another more DIY way to go about it perhaps?

Anyway, here is the video of the coolant flow

https://www.youtube.com/watch?v=TRug8-jU7f4

Thanks
Ben
 
Hi
Not entirely sure about the v6 but be patient there are a couple of guys on here who no them inside out I,m sure they will be along soon and will be able to help you .
Regards Trev
 
A couple of points spring to mind. First off. The KV6 must never be run without the water jackets full of coolant. Running the engine with the top hose disconnect is likely to cause head gasket failure at the fire rings. The liners are very thin and so heat up excessively in seconds without coolant.

From the video, the water pump is working. The symptoms you describe suggest that the there is air in the coolant jacket, maybe coupled with the pressure cap not holding the pressure.
 
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I meant to add that the over flow bottle and cap are new, with the cap appearing to hold pressure well, at least until the coolant in the bottle starts percolating.

Also I had a hose filling up the over flow bottle as I filmed the video, and only had the engine running for around 40 seconds so hopefully no damage was done there.

So I guess if that flow seems reasonable I will probably need to take a closer look at the radiator. I have a small inspection camera, maybe I can stick it in there and see how the passages look.

I suppose it might also be prudent to have the coolant tested for a head gasket leak at this stage. The engine has done virtually 0 miles since it has had rebuilt heads fitted by the previous owner but judging by the quality of work i've found else where I would not be surprised if corners were cut with the head work and fitting.

I honestly thought the water pump flow would/should be stronger than what it is in the video that's all.

Thanks
Ben
 
Ascension said:
I meant to add that the over flow bottle and cap are new, with the cap appearing to hold pressure well, at least until the coolant in the bottle starts percolating.

Also I had a hose filling up the over flow bottle as I filmed the video, and only had the engine running for around 40 seconds so hopefully no damage was done there.

So I guess if that flow seems reasonable I will probably need to take a closer look at the radiator. I have a small inspection camera, maybe I can stick it in there and see how the passages look.

I suppose it might also be prudent to have the coolant tested for a head gasket leak at this stage. The engine has done virtually 0 miles since it has had rebuilt heads fitted by the previous owner but judging by the quality of work i've found else where I would not be surprised if corners were cut with the head work and fitting.

I honestly thought the water pump flow would/should be stronger than what it is in the video that's all.

Thanks
Ben
Click to expand...

If the bottom rad hose is colder than the top hose, the radiator is doing what it's supposed to.
The KV6 bottom hose will generally be about 10° above ambient temperature, even after a good run on a hot day.
The water pump flow goes through lots of different paths, not just the radiator. This gives the impression that it's not working, however yours is.
I could see the new tank in the video but it's not uncommon to have a duff new cap.
I think you problems are air trapped in a coolant jacket. This expands causing the symptoms you describe. Has the cooling system been bled correctly and completely?
 
Don't ferget there's a bleed screw at the rear of the engine in the pipe near the bulkhead and one on the bottom of the engine at the front near the o2 sensor in the eggsource.

Cooling systems should stay sealed as they need to keep the pressure in to stop the coolant from boiling. The v6 can go to approx 109 degrees C before the rad fans come on. Hence loosing pressure or having no pressure is a big problem. Are the hoses stiff to squeeze when hot compared to being softer when cold?

I tried to do a sniff test on my v6. Never again. I would be interested to know how others do it as it releases pressure which isn't good. Don't follow the method I used below from the instructions it came with:

Engine running - check
Engine hot - check
Tester filled with fluid - check
Undo coolant reservoir cap - shiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii*

The coolant instantly started to boil as it spluttered into the coolant reservoir. I could hear it boil in the big top hose by the rad and inside the engine. I quickly put the reservoir cap back on within seconds and it continued to splitter coolant into the reservoir so I turned it oft straight away.

The tester I have is the type which allows pressure to pass through it, bubbling through the test fluid (2 sections of it) and out the top. It stand in the coolant reservoir opening at the top and should seal into it. Even when fitted correctly it allows pressure in the cooling system to escape and boil too as the pressure escapes through the tester.

cgqcYv2.jpg

coolingv6 cgqcYv2
 
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Did you pressure test the overflow bottle cap? Did you test the thernostat in hot water before installing ? Both have been know to be faulty from factory, especially the reservoir cap
 
I had a whole lot of stuff typed out but somehow it got lost so i'll try to condense what I can remember. Some questions, some answers, and some statements to provide possibly relevant information.

I tested the thermostat and it appeared to be operating correctly

I did not test the overflow cap as I don't know how, but the car has done the same thing with two different caps. Not definitive I know but it's something to keep in mind.

I was not aware of the bleed screw at the front/bottom of the engine, does this need to be opened to bleed the system or is it just a drain?

Once the system starts to warm up, all hoses feel pressurized.

The overflow cap appears to be holding pressure as it only starts to vent once the coolant in the bottle starts to percolate and the thermo fans have come on indicating the coolant temperature is up there. The temp gauge pretty much stays in the middle also untill the above point where it starts to climb, although I have not seen it above the hot mark.

I do hear boiling coolant in or around the thermostat area as well.

When I open the rear bleed screw when the system is warming up I mostly get water coming out under a bit of pressure but it also looks like some air might be coming out also, but no matter how long I leave it open it never seems to change to just water coming out. To try to explain it, it kind of sounds like a fairly serious case of diarrhea haha

The bottom hose pretty much seems to stay at ambient temperature right until the rest of the system is blowing it's top. And when it does get hot I get the feeling it's only from convection but I could be wrong.

I've had to move on to an engine swap on another car at the moment but when I get a chance i'm going to see if I can find another bleed procedure, and run through the process yet again and see if I can get a different result.

I appreciate all your comments and suggestions so far :)

Ben
 
It would also help to look at the temperature with an ODB2 code reader. I would bring the cap to a place that can pressure test them. Lookup Ford 150 pressure cap failure in youtube (same cap). It's un believable. I would also pressure test the entire cooling system to make sure.
 
If you haven't used the engine bleed screw then you have air in the engine I would eggspect.
 
If you haven't used the engine bleed screw then you have air in the engine I would eggspect.

With the engine cold remove the coolant reservoir cap and fill to the top (way above max).
Undo the bleed screw at the front of the engine and let the air out of the engine as coolant flows. Don't wear yer best t-shirt. This should stop the bubbling in the engine. fit bleed screw.
Fill the coolant reservoir to the top again and undo the rear bleed screw. Keep topping up the coolant reservoir to push more water through as required. Fit the bleed screw.
Fit the coolant reservoir cap.
Start engine and watch. You'll find some air will be pumped out and start to fill the coolant reservoir with air, along with a flow of coolant. Stop the engine and refill it as required. When the engine starts to get warm open the rear bleed screw and let any air out. Wiggle the pipe a bit as you do it. Fit bleed screw again.
Switch engine off and top up the coolant reservoir to max then take it for a short drive. You will find revving the engine above tick over as you drive will flush more air out into the coolant reservoir.

The above is what I did to mine recently when changing the coolant.
It helps a bit if you can lift the rear wheels as that gets more air out.
On my test drive I went up/down a hill to help with this.

NEVER let the pressure out of the cooling system when it's warm/hot with the engine running.

Nodge will be able to confirm the proper process to get the air out.

Edit:
After a few days I got a small amount of air out of the rear bleed screw so I will add that to the list above. Mot much, but some. This was after my test drive, when it had cooled down. Only do this when the engine is cold and don't let the coolant reservoir drop low when doing it. I filled mine above max and bled it down to the max level, whilst on level ground.
 
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Hippo said:
If you haven't used the engine bleed screw then you have air in the engine I would eggspect.

With the engine cold remove the coolant reservoir cap and fill to the top (way above max).
Undo the bleed screw at the front of the engine and let the air out of the engine as coolant flows. Don't wear yer best t-shirt. This should stop the bubbling in the engine. fit bleed screw.
Fill the coolant reservoir to the top again and undo the rear bleed screw. Keep topping up the coolant reservoir to push more water through as required. Fit the bleed screw.
Fit the coolant reservoir cap.
Start engine and watch. You'll find some air will be pumped out and start to fill the coolant reservoir with air, along with a flow of coolant. Stop the engine and refill it as required. When the engine starts to get warm open the rear bleed screw and let any air out. Wiggle the pipe a bit as you do it. Fit bleed screw again.
Switch engine off and top up the coolant reservoir to max then take it for a short drive. You will find revving the engine above tick over as you drive will flush more air out into the coolant reservoir.

The above is what I did to mine recently when changing the coolant.
It helps a bit if you can lift the rear wheels as that gets more air out.
On my test drive I went up/down a hill to help with this.

NEVER let the pressure out of the cooling system when it's warm/hot with the engine running.

Nodge will be able to confirm the proper process to get the air out.
Click to expand...

This is the V6 bleeding procedure ^^^^. Thanks for taking the time to write it up Hippo ;)

A "Hints & Tips" section would be handy for stuff like this!

I will just add. Once this procedure is completed, any remaining air will come out over the next few hundred miles. So keep checking the header tank, adding coolant when it drops below the MAX mark (when cold)
 
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Thinking back... after a few days I got a small amount of air out of the rear bleed screw so I will add that to the list above. Mot much, but some. This was after my test drive, when it had cooled down. Only do this when the engine is cold and don't let the coolant reservoir drop low when doing it. I filled mine above max and bled it down to the max level, whilst on level ground.

I would also like to add the optional dropping of the bleed screw. After a lot of messing about to try and find if I washed it out with a jet of water. It can somehow hide on top of the ird out or reach or sight. the ird has strengthening strips which hide things.
 
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you say theres a bleed screw on front of engine? where is this ?

all i can find on my v6 is a bleed screw on the pipe work going into the bulkhead which i assume is to help bleed the heating
 
The engine bleed screw is documented but I often get the feeling it's missed as peeps may think there's only one, which is the one by the bulkhead at the top rear of the engine.

The lower bleed screw on the engine is used to get air out of the engine which would be trapped somehow if it isn't bled from there. I'm guessing when I say this... I think it's a case of the flow of coolant out of this bleed screw allows coolant to flow through the engine with a bit more force, which in turn helps to push air out. If this isn't done then the engine will have hot spots due to air trapped inside, which isn't good news. Sadly a lot of peeps don't know of the engine bleed screw and cause themselves engine problems.

When draining the coolant system it's betterer to drain as much as you can by removing the coolant reservoir cap, then the bottom radiator hose. Then remove the engine bleed screw. If you don't do it in this order you risk flushing more dirty/contaminated coolant through the engine from the rad etc which isn't ideal.

Engine bleed screw is located above the front O2 sensor on the v6.

jimFBml.jpg

DSCN5100 jimFBml
 
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Thank you for the picture, always easier with a picture.
I haven't had a chance to play with the car yet unfortunately but now I know exactly what to look for, so thanks :)

Ben
 
Hi Guys,

I just bought a 2003 V6 Freelander. It's losing coolant from the expansion bottle from the cap. I will replace it asap and hopefully that'll solve the fluid loss. My V6 Freelander runs very hot. Is this normal? After about 20 mins of normal driving the fans kick in and it sounds like a jet is about to take off! Again, is this normal?? By the way the temperature gauge inside the car sits bang in the middle. Thanks.
 
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Andythedrum said:
Hi Guys,

I just bought a 2003 V6 Freelander. It's losing coolant from the expansion bottle from the cap. I will replace it asap and hopefully that'll solve the fluid loss. My V6 Freelander runs very hot. Is this normal? After about 20 mins of normal driving the fans kick in and it sounds like a jet is about to take off! Again, is this normal?? By the way the temperature gauge inside the car sits bang in the middle. Thanks.
Click to expand...

It sounds like you need to replace the pressure cap and possibly the expansion tank as well. The caps are known to fail and tanks are known crack around the neck.
For ease, it's best to start your own thread is it gets confusing for others trying to follow or offer advice ;)
 
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