Thermostat V6 190 leak & re-fitting

[Arctic]

Originally Posted by P63500S

I have changed two thermostat's on two kv6 engined cars and found both stats were leaking from the o rings.

My advice to all members is to use gasket sealant on the o rings of the stat and pipes.
After two years and counting no more leaks

Hi Nicholas
What gasket seal did you use ? and if you notice I too went 2 yrs with out no leaks but only 3,700 miles so hopefully you using gasket seal you may last longer time will tell us.

I still need to sort out my thermostat yet which looks like it will be after the nano meet now Arctic

[trikey]

I have changed a few KV6 thermostats, I think the key to stopping the leaks is to ensure the surfaces of the engine where the O rings seat are perfectly clean, I clean using scotchbrite before fitting the new parts.

[Arctic]

I have had the misfortune recently to find that my thermostat is leaking into the V of the engine.

I have recently found a leak from the thermostat on my MG ZT 190 V6.
I check the car once a week for all hose leaks etc, all fluids levels be it oil or water, so as per usual on 9th March Sunday I did all the relative checks and everything was fine.

In the mean time I took delivery of a new coolant cap which I had purchased from a vender to see it's quality for the price that is another story, anyways on the 12th March coolant cap arrived the very next day 13th March i thought i will change the cap and see how it looks and works with regards to the original.

Once i took the original cap of the header tank i could see that the level of coolant had drop from the max mark to a fraction below the minimum mark only checked three days ago all was well and have only driven the car 30 miles in those three days, so i take of the engine cover look into the V and there is the problem looking me right in the face coolant loss from the thermostat albeit only a little but never the less a leak.
1

As you can see this is very fresh coolant as it is as red as blood, now my MG ZT 190 was fitted with a new thermostat on the 21/01/12 and as only covered approx 3,700 miles since it was fitted. Fig 2
2

I was surprised to find this in the mean time i have not driven the car and ordered a new thermostat which arrived 18/3/14. Fig 3
3

Well I finally got round to finding enough time to change the thermostat Saturday 29th March, first I decide I will take of the engine cover and check to see if the leak as got any worse, the answer was no Fig 4/5/6 below.
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5

6

So task begins I take off the under tray so I can remove the bottom coolant hose to drain the system and the first of the nightmare shows it's ugly head green A/C fluid on the under tray Fig 7
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As the car is on the ramps at this present time I look up directly where the A/C fluid was in relation to it on the under tray to be greeted with even more green fluid on the under side of the compressor Fig 8
8

I then look closer only to find also that the oil cooler maybe leaking also but yet to prove this Fig 9
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Then I decide to shine a torch all over the under side of the engine and find even more leaks, around the gear box. Fig 10
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further up more leaks from the timing belt cover, now this happened just after I had the belts changed in 21/12/2012 the car was taken back and the camshaft oil seals where replaced, due to them leaking not long after the belt change, I kept an eye on it for a while but now it is back again Fig 11
11

This engine was as dry as bone until the belt change in 2012 coincidence ? if so the camshaft leak is not that's for sure, rubbish seals I would say, there is also a leak along the back where the exhaust bolts to the engine I still have to find this source maybe the rear bank cam seals ? Fig 12/13
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13

There is also a leak around the oil filter or it is traveling to that point from some where else Fig 14
14.

I will post how I removed the thermostat and refitted over the next few days keep looking in Arctic

[SD1too]

Hello Steve,

The various oil deposits may well have got there by dripping or running from a point higher up. There may also have been spillages when the cambelts were changed. As you say, the seals at the end of the camshaft may be responsible since it's said that they're difficult to fit (perhaps the garage refitted the old ones). It's unlikely that your engine will have sprung several oil leaks since October which aren't connected with the cambelt work. I would clean off the oil as best you can and re-inspect first with the engine running at idle then after a short journey at low road speeds (to limit the spread of oil by airflow due to the car's movement).

I agree though about the green deposits on the underside of the compressor. Was that removed by the garage when replacing the belts? Again, if you can, I would wipe off the stains then see if they return.

In the meantime proceed with the cooling system repairs.

One question Steve: with your skills, why on earth didn't you renew the cambelts yourself?

Simon

[Arctic]

Originally Posted by SD1too

Hello Steve,

The various oil deposits may well have got there by dripping or running from a point higher up. There may also have been spillages when the cambelts were changed. As you say, the seals at the end of the camshaft may be responsible since it's said that they're difficult to fit (perhaps the garage refitted the old ones). It's unlikely that your engine will have sprung several oil leaks since October which aren't connected with the cambelt work. I would clean off the oil as best you can and re-inspect first with the engine running at idle then after a short journey at low road speeds (to limit the spread of oil by airflow due to the car's movement).

I agree though about the green deposits on the underside of the compressor. Was that removed by the garage when replacing the belts? Again, if you can, I would wipe off the stains then see if they return.

In the meantime proceed with the cooling system repairs.

One question Steve: with your skills, why on earth didn't you renew the cambelts yourself?

Simon

Hi Simon.
I thank you for your input always appreciated, spillages from when the cam belts were changed, were cleaned up at the time and later on by me.

New cam seals were fitted at the time of the change of the belts as I was there watching, I did however have to take the car back because they were leaking after a very short time, and they were changed again, the oil was also present after round the oil filter after the belt fitting this was pointed out when I took the car back for the second set of cam seals to be fitted, the oil filter was again changed, the car as only travelled 3.700 miles since the belt change.

Simon the reason I did not change the belts myself at the time were several, I had never done V 6 belts change before, I did not have the tools, and also I did not have the time as I bought the car to save which I knew would need belts, new clutch, tyres all round, a couple of doors and more, but it a been an on going project and looks like it still is now.

I think i will as you say clean up and then see if I can see where the point of the leaking is coming from, the A/C was filled at the same time as the cam belts were changed but by the time i took it back to have the seals changed it had leaked.

I was told that the condenser pipe seals were leaking, but at the time of filling this was not pressure tested just vacated and re-filled and no dye was inserted to check for leaks.

I then changed the condenser along with the fan had it all refilled at a different place by a machine which cost £50.00 and is supposed to be state of the art.

At the last mot I had in January I asked them to check the A/C as I felt it was not blowing cold enough and they found it to be low on gas, they re-filled it and Saturday was the first time I have been under the car since the MOT.

So once I have it up and running I will pop it back round to them so they can check it again. cheers Arctic


PS do you think the compressor could be leaking from the gasket at the top right hand corner of the photo below, the gasket seems to be pressed out ?

[SD1too]

Originally Posted by Arctic

.. do you think the compressor could be leaking from the gasket at the top right hand corner of the photo below, the gasket seems to be pressed out ?

It's hard to tell from a photo Steve. You're in a better position to judge that. But I can't see how a leak from there could travel upwards around the casing then stop neatly at the pipe unions (seen in the picture you provided by e-mail). A mobile company's detection equipment would probably help.

Simon

[Arctic]

On the 13th March I discovered I had a leak from the thermostat on my MG ZT 190 I noticed this as the coolant in the header tank was low, so I checked in the V of the engine and sure enough I could see the red coolant not much but enough to have to remove and replace the thermostat.

Below is how I removed and fitted the thermostat I hope this helps some other members if they have to do the same job, remover the under tray before starting the task,the thermostat I removed had only been fitted for 2 years with limited mileage of about 3.700miles.

First remove the engine cover two 8mm bolts Fig 1
1

Remove the cover and put it in a safe place with the bolts Fig 2
2

Using a torch and shinning it through the gap in the manifold I can see the leak Fig 3
3

The next step is to remove the air filter box from the engine bay, loosen the hose clip on the throttle body inlet hose Fig 4

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Pull off the small air induct hose pipe Fig 5/6
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Next you can pull up the air box it may be stiff as it sits in the holes and is held in by the lugs under the box Fig 7/8
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You now need to release the Shannon tube from the air box Fig 9/10
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Air box removed put it safe with the engine cover in the boot of the car out of arms way Fig 11
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You may see a little oil in the air induct hose this is normal and can be cleaned out before re-fitting Fig 12
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There may also be a little oil in the throttle body again do not worry Fig 13
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You can now see the three hoses that are connected to the thermostat and the bleed screw Fig 14
14

Later you will also need to remove the bottom hose that is the reason for removing the under tray before starting the task. Fig 15
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The next parts to remove are the breather hoses, the first one is the one connected to the vis motor & throttle body and the front Fig 16/17/18/19
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These hoses are removed by depressing the red locking collars Fig 20/21
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You will have to use a screw driver to depress the locking collar connected to the vis motor Fig 22/23
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The last locking collar on the top breather pipe is connected to the top of the throttle body and is black an again a screwdriver may be used Fig 24/25
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You can now pull back the engine bracket and feed the hose past it Fig 26/27
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With the hose removed again put it in the boot for safety Fig 28
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You can now remove the second breather hose Fig 29
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Start at the front cylinder head again depress the collar Fig 30/31
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Them move to the collar on the manifold Fig 32/33
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The last part of this hose to be removed is the T piece, this is held in by a white collar Fig 34
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This white collar needs to be pressed in at both ends and twisted to release the hose Fig 35
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Once remove inspect it and make sure it is in good order no cracks or splits and put it in the boot Fig 36
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Next step disconnect the vacuum hose from the idle control valve Fig 37
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Place this hose to one side for now Fig 38
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You can now unplug wiring plug from the throttle body Fig 39/40
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unclip the next plug underneath by depressing the metal spring clip Fig 41/42/43
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With the two wiring plugs removed set them out of the way Fig 44
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Next we turn our attention to the throttle cable Fig 45
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lift the throttle lever and remove the cable 46/47
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We now need to remove the throttle body it's self which is secured to the manifold by four torx 30mm bolts two above and two below Fig 48/49/50
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You will need to use a long reach socket and ratchet with 30mm torx start with left top bolt Fig 51
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Next bottom left Fig 52
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Bottom right Fig 53
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Last top right Fig 54
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Once removed inspect and clean up with a bit of WD 40 and in the boot with it Fig 55
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You can now put a container under the bottom radiator hose and remove it to let out the coolant Fig 56/57
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This hose with the bleed screw in it will be removed once the coolant as be drained off Fig 58


To Be Continued

[trimani]

Had same leaking problem after 12 months. I am now fitting Metal Bodied one from Kaiser.

trimani

[Simon.h]

I bet this is where your compressor is leaking from-

http://www.the75andztclub.co.uk/foru...ght=compressor

[Arctic]

Originally Posted by Simon.h

I bet this is where your compressor is leaking from-

http://www.the75andztclub.co.uk/foru...ght=compressor

Hi Simon.
Thank you for the heads up I will be taking a closer look next week sometime, now that I have fitted the thermostat cheers Arctic