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Coolant level sensor retrofit solved. |
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vaho |
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Joined: Jun 25 2015
Member No: #2228
Location: Tallinn |
Great!! |
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PIT |
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Joined: Jun 14 2016
Member No: #2671
Location: Sofia |
Hello guys. I showed the tutorial to a friend with C6. He wanted to know why Citroen didn't install the sensor in the cars and why they stopped installing it on some cars (like the petrol V6). He talked with the main mechanic in local Citroen dealer and yesterday my friend called me. He said the the mechanic told him that this was because of many failures of the sensor. The sensor breaks somehow and water/coolant starts to flow through the cable to the BSI and there were many damaged computers. He also said that there was an official PSA document explaining that failure on many C5 and 407. Many cars were called for service to remove the sensor and install cap on the expansion tank. This sounds a little bit strange for me. But the mechanic told him that he personally remembers that time. So what do you think? |
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vaho |
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Joined: Jun 25 2015
Member No: #2228
Location: Tallinn |
Unbelivable BS, I can not believe that. The coolant tank and Fuse box are at the opposite sides of the car, even if the coolant rises so much that it will flow out from the top of the tank (which it normally never does, you can run the engine the cap off and nothing will flow out) it takes something like a magic trick to flow some 1,5 meter through the cable, up and down. If you can please ask the PSA document, I think there must be something lost in translation. | ||
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David Hallworth |
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Member No: #90
Location: Glasgow |
Have to agree with Vaho on this one. Sounds like someone just didn't want to say "I don't know". David. |
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Hattershaun |
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Joined: Dec 19 2010
Member No: #320
Location: Bedfordshire, UK |
I believe the issue was one of capillary action of water running along cable runs. Not sure if this concerns C6, but definitely concerns the Citroen Relay van (which FIAT build, blame the Italians!). Water was going into the fuse/relay box, causing much mayhem. |
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Tjensen |
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Joined: Jul 17 2012
Member No: #954
Location: Bergen |
I also heard this story from someone with occupational experience with Citroen repairs in their system. He remembered that there was some information from PSA that there was some kind of leak from the sensor that ruined electrical connections and made them stop with the sensor system (Norway) | ||
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gmerry |
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Joined: Dec 11 2009
Member No: #21
Location: Scotland |
Water migrating along cables is a real phenomena: I have seen this happen over distances of more than 200m on subsea control cables and on the automotive front, other Citroens and Fords have suffered this problem with temperature sensors. For the C6 level sensor as per this forum topic, PSA have the expertise to specify cables with water block construction if they wanted to solve the potential water migration problem. I'm still guessing it was a conscious decision to delete the sensors for reasons of cost or similar. For the retrofit situation as discussed here, its a balance of a small risk of a fusebox problem versus a very high risk of engine damage due to loss of coolant. So the answer should be pretty obvious. regards G |
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PIT |
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Joined: Jun 14 2016
Member No: #2671
Location: Sofia |
Yes it is capillary action of water running along cable runs, not like through a hose But this is enough to damage the other side, because it goes directly to the PCB. Connectors are made to prevent water from getting in from outside, but not from inside the cables... | ||
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vaho |
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Joined: Jun 25 2015
Member No: #2228
Location: Tallinn |
well, digging the internet indicates that PSA had indeed problems with sensors but they were electrically failing rather than coolant flowing through the wires. The common claim is that sensors are alerting when there is no reason. I found one thread where the dealer changed the faulty sensor (gave a warning when there was no coolant loss) on Peugeot RCZ to a dummie and argued that the wrong signal could cause some interference with ECU - or something like that. http://peugeotrczforum.co.uk/viewtopic.php?f=6&t=6987 I found one water migration issue also but it is a coolant temperature sensor not a level sensor on a DS3: Had 1.6VTi in today for engine management light and anti pollution fault. Cause of fault was a leaking coolant sensor, coolant then travelled up the wiring loom back to the ECU thus short circuiting the board inside. New sensor, new engine bay wiring loom and new ecu just £1700! This engine is a similar layout to the THP in the DS3, same sensor, same wiring, same ecu....hope this isn't where your coolant is going too :-/ |
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cruiserphil |
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Member No: #38
Location: Celbridge |
Lads, My friendly Citroen independent told me that there was recall on coolant level sensors to be removed. Not sure if included C6 but he was not surprised the C6 was not fitted! PIT's friend's mechanic's memory is OK it seems! Best regards, Phil C. |
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vaho |
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Joined: Jun 25 2015
Member No: #2228
Location: Tallinn |
Ok, did some logical and rational thinking , if I am wrong please correct: First let´s assume that the water migration is possible, which it seems to be. Now in order to migrate to the fuse box there has to be pressure in one end of the wire and pressure release in the other. There is certainly pressure in water tank so if there is a crack in the sensor coolant could rise up into the sensor. The crack has to be below the coolant level though. Next in order to get to the wires the coolant has to get to the sensor circuit board first. At that point the water surely causes sensor malfunction and you already know something is wrong. If it somehow does not malfunction and due to the fact that the sensor connector is sealed and the pressure and water has to go somewhere, it just starts to travel inside the wire to the fuse box where the other end is connected. There has to be very little room inside the wire though, so if the coolant finds another and easier way, it will certainly flow to that direction. This leads to the conclusion that if you remove the sensor connector seal there is no pressure buildup towards the wire anymore and water just flows out of the connector. This happens of course only then if the sensor is cracked. So if somebody is worried just remove the connector seal as a precaution. Worst case scenario then is to get some corrosion on the contacts due to the outside moisture, but that can be sorted out with cleaning. |
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e3steve |
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Joined: Jan 21 2013
Member No: #1163
Location: Warsash, Hants & Palma de Mallorca, Spain |
Removal of the seal seems logical, Vaho. The protection of the connections against moisture ingress can be effected using silicone grease, via a small, stiff brush (Poundland: £1 for ten toothbrushes!). | ||
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PIT |
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Joined: Jun 14 2016
Member No: #2671
Location: Sofia |
This assumption sounds wrong because as we talked this is basically due to capillary action of the water. So you don't need pressure difference on both ends of the cable. | ||
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vaho |
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Joined: Jun 25 2015
Member No: #2228
Location: Tallinn |
Yes you are right. Capillary action (sometimes capillarity, capillary motion, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid In that case the removal of the seal does not help of course. So what can we do? Apparently nothing, beside to check the connector or like PSA did, remove the sensor. I am willing to take the risk though. |
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321dave |
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Joined: Sep 09 2011
Member No: #614
Location: Dublin |
Hi all, how about a drain of some type, or diversion if and when the event were to travel across to the fuse box. What or how could that be achieved? Steve's silicon idea is a good start, how much water were psa talking about? | ||
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