307 1.6HDI 2007 - Coolant leak

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khaleel01416
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307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

Hi,

quite new to the forum but have seen many peuple find solutions from some of the bright minds on here. so here we go...

started with a failed oil cooler ended up with thick black oil inside the coolant tank was quite bad, ended up ordering a brand new cooler and seals for the housing...turns out was only the rubber seals missing on the housing thus explaining the amount of the leak however after replacing this it was time for the dirty work the flushing and getting the coolant back on its feet.

started by getting a new coolant tank as i realised i was having pressure problems and it was due to the fault of the cap the water kept boiling and overflowing after replacing this there was a huge difference in pressure however it still was not holding pressure for very long turned out it was the rad to coolant return pipe as it was missing the washser after replacing this an the temperatur sensor the pressure was perfect no more boiling and all the pipes went hard and pressurised.

however now it holds water as ive cleared a few airlocks that would have built up but it doesnt hold it for long once i set off and drive it around the block the expansion tank is empty again i am constantly filling it with water ther are no visible leaks at all and for days i was wondering where the water was going now under full pressure looking under the car i found quite a bit of water dripping out just behind the engine block where the coolant hose connects to the plastic housing i cant pinpoint exactly where it is leaking but im almost certain its the plastic housing or flange of some sort at first glance i thought it was dripping off a bolt but turns out its a small hairline leak on some sort of plastic housing just above my oxygen sensor i just dont know how a leak that small can empty my expansion tank out so fast.

what could it be thats actually leaking?

im trying to find diagrams of my engine and the coolant system of my car so i can understand the problem and get it fixed or replaced ive tried to have a fe mechanics look into it but they all struggled to pinpoint the leak until i got a chance to use my friends ramp and have a look myself with a torch and after some tracing managed to find roughly where the leak is, just need to know what the housing is thats leaking.

i know its a lot of information and still probably not enough but any suggestions or expertise is greatly appreciated.

doctle
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Re: 307 1.6HDI 2007 - Coolant leak

Post by doctle »

did you follow the procedure for changing the coolant and bleeding the system?

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white exec
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Re: 307 1.6HDI 2007 - Coolant leak

Post by white exec »

Hi, and welcome.

I am very familiar with what you painfully describe - a failed oil cooler, allowing black engine oil to be injected into the cooling system. It has happened to me twice, and takes a lot of work to get it cleaned up and back to normal.

The oil in the coolant can destroy the rubber seal on the expansion pressure cap, and this will prevent pressurisation, and allow boiling and on-going loss of coolant.

It is essential to remove ALL traces of oil in the cooling system, to prevent new replacement pressure caps from becoming damaged. Detergents, etc are only partially successful at this, and what I can recommend is a Liqui-Moly product: Radiator Cleaner, 300ml, code 2506. Buy two, and follow the instructions on the can. It works really well.

Also make sure you have bled air out of the system really thoroughly, as any trapped air can cause localised boiling and coolant loss.

Another possible cause of coolant loss is a failed thermostat. If in doubt, just replace it - cheap enough, and easy to do while you have the system drained for cleaning.

khaleel01416
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Re: 307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

Hi,

thank you for your prompt response to my post appreciate it.

it is a nightmare but after replacing the tank and cap and after at least 20 flushes the system now looks pretty clean i do get the odd rainbow layer on top of my water but dtill looks very clear when its not gone.

I thought it may be thermostat but it doesnt seem stuck i get the heat coming through and all the farns work, well the second speed fan kicks in good and hard but thats only for when the engine over heats the low speed fan kinda works when it wants to.

so far im almost certain i can see the leak i just dont know where the housing leads to its the plastic housing that my coolant tank hose connects into.

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GiveMeABreak
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Re: 307 1.6HDI 2007 - Coolant leak

Post by GiveMeABreak »

Post your VIN up so I can get you some details of the cooling system, which is what I think you want.

khaleel01416
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Re: 307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

Hi sorry for the late reply was having some troubles with my login details (noon problems) thank you for everyone's help

And yes that's exactly what I need a diagram of the coolant system would be amazing

My vin number is as follows: VF3**************[VIN obfuscated, can be read by forum staff] 85063014

Seems like right one, found it on the windscreen just under the wipers.

Thank you again appreciate it!

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Re: 307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

GiveMeABreak wrote:
26 Sep 2019, 10:06
Post your VIN up so I can get you some details of the cooling system, which is what I think you want.
Just to update I decided to throw some k seal in ( admittedly knowing it's not the most trusted product) hoping for the little leak to heal which it did for a little while until POP all my coolant started instantly leaking out from under the engine.

Decided to take car to a friends garage which is where it's currently at with the sub frame and few things stripped off it's the plastic housing that connects to block the coolant expansion pipe goes into the same plastic housing, it kinda goes across the back of the engine.

Seems like it's going to be a big job to get that replaced.

Will take a picture of the plastic housing tomorrow but here's one of the part prior when it was only leaking.
Attachments
This was a picture taken before today's incident , it's the weird flange V looking plastic with the flat end that's now completely blown off. That is the pipe I'm trying to locate and replace.
This was a picture taken before today's incident , it's the weird flange V looking plastic with the flat end that's now completely blown off. That is the pipe I'm trying to locate and replace.

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Re: 307 1.6HDI 2007 - Coolant leak

Post by RichardW »

307coolantpipe.JPG
Not as expensive as I feared at £79.24....

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white exec
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Re: 307 1.6HDI 2007 - Coolant leak

Post by white exec »

Just a few afterthoughts...

- The sandwich-type oil coolers usually fail internally, when their steel/aluminium innards corrode and perforate, allowing higher pressure oil to enter the lower pressure cooling system. If either of the two large square-section O-rings (one under the oil filter, an identical one under the cooler) failed, all you'd get is an external oil leak, but no oil in the coolant.

- Internal corrosion of the coolers (especially those with some aluminium innards) is not unknown, and is made more likely by coolant quality/strength being neglected. "Mixed metal" components are particularly vulnerable.

- One more known cause of oil-in-coolant is related to the head gasket, where the oil way feeding the cylinder head (often a simple small O-ring sitting in one corner of the gasket) goes leaky, and allows oil under pressure to get into an adjacent waterway. If you're lucky, an oily corner on the outside of the block might give a clue to this.

- Thankfully, oil in the coolant will float to the top (less dense that the coolant) and largely accumulate at the highest point – usually the expansion/header tank. The thick oil slick there can be "fished out" by dipping the tank with pieces of rolled up kitchen tissue. The oil will cling to it, leaving mainly clean coolant behind. Expect to have to do this fishing out dozens of times in succession, with engine running, and with short spells at high revs. When everything looks pretty clean, and staying that way, finish off the cleaning procedure with the LiquiMoly 2506 fluid. That should leave the system really clean.

- Use a good quality ready-mixed coolant mix at full strength. Do not use tapwater. Do not mix coolant types or brands; stick to the same one for all topping up. Coolant colours mean nothing; there are no agreed standards.

You likely know all this already.
Have just added some bits after my saga here a while back.

khaleel01416
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Re: 307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

RichardW wrote:
27 Sep 2019, 20:19
Image

Not as expensive as I feared at £79.24....
Thank you so much for this really appreciated that exactly what I needed will get the part of dealers.

Goes to show real heroes don't wear capes thanks guys!

Thank you Chris for the thorough explanation will definitely keep that in mind.

Will give you all an update hopefully once it's back out, hopefully this will come to use to anyone else experiencing the same problem.

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Re: 307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

Just an update car came out of garage yesterday and yes had the leak all sorted! Wasn't too bad buddy charged me 60quid for labour and had car in garage for 3 days most of it as we were waiting for the part.

However now after filling car up with antifreeze the water does not seem to hold in the expansion tank.

I fill it up take it for a drove check again all gone!

Its driving me crazy this coolant issue in this car there is no visible leak anywhere at all water just seems to magically disappear and that too quite fast.

I just changes expansion tank cap twice the last one being brand new from auto part store for my car.

However I've realised it's when the car gets pressurised the water disappears.

I just don't know where it goes.

Checked the oil cap no obvious signs of head gasket.

Another thing to add now my digital temp gauge is just flashing and not displaying temp I've realised also the faster I drive the faster it overheats, my heaters start to blow cold, hence no water in the expansion.

When I remove the coolant cap a little water comes up with the release of pressure however within seconds that gets sucked in too and car needs more coolant again.

Is there anyway to bring this coolant back to life a d just have the car working like every other average car lol.

Thank you all for all your support wouldn't have got this far at least had it not been for some of the smart minds on here, much appreciated.

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white exec
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Re: 307 1.6HDI 2007 - Coolant leak

Post by white exec »

Is it possible that when the car was refilled with fresh coolant, it wasn't thoroughly bled of trapped air.
Many systems have a specified bleeding procedure.
An air pocket can cause localised boiling, which expels coolant. Attach a bottle to the overspill pipe from the coolant tank to check whether any is being expelled.

doctle
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Re: 307 1.6HDI 2007 - Coolant leak

Post by doctle »

Is there any damp inside the car?

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xantia_v6
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Re: 307 1.6HDI 2007 - Coolant leak

Post by xantia_v6 »

I think that the only way to find a coolant leak that only occurs under pressure is to test it under pressure while the system is cold, with a pump kit like: https://www.ebay.co.uk/p/DA-YUAN-YT1058 ... 6367&rt=nc
or some home-made alternative.

If the level in the header tank rises when the cap is removed, it indicates either that there is air in the system, or that one of the cooling system hoses is expanding under pressure. Some of the hoses (e.g. the radiator hoses) have loose external cloth braiding, and if that tears, it allows the hose to bulge when the system is under pressure, lowering the coolant level in the tank.

khaleel01416
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Re: 307 1.6HDI 2007 - Coolant leak

Post by khaleel01416 »

white exec wrote:
02 Oct 2019, 07:29
Is it possible that when the car was refilled with fresh coolant, it wasn't thoroughly bled of trapped air.
Many systems have a specified bleeding procedure.
An air pocket can cause localised boiling, which expels coolant. Attach a bottle to the overspill pipe from the coolant tank to check whether any is being expelled.
I did attach a bottle to the over spill and it seems to sputter with little bit of coolant until I rev it with each rev it shoots a fair amount until I stop and then it also stops filling the bottle I'm guessing that's normal?

I'm just struggling to understand what it could be and how the coolant is there all fine after I fill a nice 2 litrss of mix I bleed the system for a good 15 minutes I then close the cap and take it for a drive check it after literally a few minutes the whole tank is empty again fill it up take it for a spin and empty again I have checked the foot well inside no damp or water after replacing the water intake hose and having full pressure zero leaks anywhere just disappears it has to go somewhere logically I dont think that much water can just evaporate within that short amount of time had a brand new expansion tank cap for my car from dealers part store.

Could my issue be the expansion tank itself as I've had a brand new cap however the thread end on the neck of the tank itself seems quite worn and if I tighten the cap too hard well just a tad over hard after it's quite tight it kinda loosens up again.

Not sure what it could be I'm starting to just give up but hoping it's just something as silly as the tank itself.