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Old 22nd May 2019, 00:42   #1
Copilot
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Question 2.0 V6 possible overheating?

Yesterday happened something strange.

Got stuck in heavy traffic in the city. Was warm weather in Denmark (around 23º) and after some time the engine temperature rose up to 99º (measured on IKE). Then I noticed some smoke coming out of the engine as well as more engine vibrations followed by a significant loss of power.

As the temperature didn't reach 100º at any point, I decided to turn on the A/C in order for the fan to kick in, which in fact reduced the temperature to 90º.

Anyway, I pulled over and turn the engine off, checking the engine bay. I noticed a spill of coolant.

I wait until the engine temperature was around 70º then I started the engine again and keep driving and everything was fine. No spill, no power loss, no vibrations from the engine and the temp around 91º.


Some facts:

The thermostat was changed a few weeks ago for a reinforced one bought in DMGRS. No leaks found so far.
All the 3 speeds of the Radiator fan are working.


Can someone point me the direction of what could be happening?
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Old 22nd May 2019, 01:54   #2
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Originally Posted by Copilot View Post
Yesterday happened something strange.

Got stuck in heavy traffic in the city. Was warm weather in Denmark (around 23º) and after some time the engine temperature rose up to 99º (measured on IKE). Then I noticed some smoke coming out of the engine as well as more engine vibrations followed by a significant loss of power.

As the temperature didn't reach 100º at any point, I decided to turn on the A/C in order for the fan to kick in, which in fact reduced the temperature to 90º.

Anyway, I pulled over and turn the engine off, checking the engine bay. I noticed a spill of coolant.

I wait until the engine temperature was around 70º then I started the engine again and keep driving and everything was fine. No spill, no power loss, no vibrations from the engine and the temp around 91º.


Some facts:

The thermostat was changed a few weeks ago for a reinforced one bought in DMGRS. No leaks found so far.
All the 3 speeds of the Radiator fan are working.


Can someone point me the direction of what could be happening?
Maybe an airlock from the thermostat change that caused a coolant temp spike that caused a boil over (shouldn't have at 99C, though) and the steam/moisture caused a loss of spark on a front cylinder. Just thinking out loud.

Cheers,
Glenn
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Old 22nd May 2019, 07:32   #3
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Whereabouts did you notice the coolant spillage?

It's quite possible that you had an airlock if the system wasn't refilled by the book after the thermostat change. Air will heat up more than coolant and then if the bubbles find their way out through the expansion chamber they can take some fluid with them. But where you found the spilt coolant would be a great help.
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Old 22nd May 2019, 10:24   #4
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It's quite possible that you had an airlock if the system wasn't refilled by the book after the thermostat change.


Simon
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Old 22nd May 2019, 17:25   #5
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Quote:
Originally Posted by slovcan View Post
Maybe an airlock from the thermostat change that caused a coolant temp spike that caused a boil over (shouldn't have at 99C, though) and the steam/moisture caused a loss of spark on a front cylinder. Just thinking out loud.

Cheers,
Glenn
Isn't normal the temperature reaching 99º or 100º in heavy traffic on a warm day? Then why the fan only starts at 100º? Should start earlier than.


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Whereabouts did you notice the coolant spillage?

It's quite possible that you had an airlock if the system wasn't refilled by the book after the thermostat change. Air will heat up more than coolant and then if the bubbles find their way out through the expansion chamber they can take some fluid with them. But where you found the spilled coolant would be a great help.
It came out from the coolant pressure cap for sure. There was coolant around the expansion tank when I opened the bonnet.

The loss of power and the engine vibrations makes me a bit nervous about what actually could have happened. Maybe a lack of spark in the front cylinders due to moisture as slovcan mentioned?

So seems I need to do a proper coolant refilling following the MGRs method.
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Old 22nd May 2019, 18:44   #6
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Isn't normal the temperature reaching 99º or 100º in heavy traffic on a warm day?
Yes.
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Then why the fan only starts at 100º?
Because that's the way MG Rover designed it.
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So seems I need to do a proper coolant refilling following the MGRs method.
Here it is for you.

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Old 22nd May 2019, 19:33   #7
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And the most important question. How much water did you loose?
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Old 22nd May 2019, 20:20   #8
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Originally Posted by SD1too View Post
Yes.



Because that's the way MG Rover designed it.



Here it is for you.



Simon
Simon I'm confused. Can you help me understanding this:

What is the optimal running temperature of the KV6?
If 98° or 99° isn't normal then the fan should kick in before engine can reach this temperatures, don't you agree? Or MG Rover had other thoughts? 🙄

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And the most important question. How much water did you loose?
Good question. The level was around 2 fingers below the MIN mark placed in the right side of the expansion tank.


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Old 22nd May 2019, 20:32   #9
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Or there again, how much did the coolant drop after the belch?

Sounds to me that you had an airlock but it then cleared itself with the “burp” and then it was fine afterwards. If an airlock then I would have expected the coolant level to go down in the expansion tank after first overflowing, OK you lost some through the cap, but level of drop in the expansion tank suggest to me an airlock.

Mine overheated and vented coolant when I first bought it despite a working fan and minus 12 outside, caused by an airlock, but at a much higher temperature. Didn’t notice any power loss but then again I struggled to get home on barely tickover as the temperature shot up as soon as I pressed the engine. The car had rejected all “professional” attempts to bleed it. It's been fine ever since I bled it and my normal temp is around 95 / 96.

If the machine is happy now I’d continue to use it, monitoring the IPK temperature as you are doing and checking the coolant. Refilling the coolant again and risking another airlock seems asking for trouble.

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Old 22nd May 2019, 22:32   #10
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I think the fan is set to kick in at 104F. Oops, 104C.
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Last edited by slovcan; 22nd May 2019 at 22:34..
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