My 4 year old 306 Diesel seems to have a small problem. It is used for a relatively short run each day 5 miles each way and each day loses water from the radiator (visible on the garage floor in th evening). It appears to be coming from the overflow tube at the top next to the filling hole.
Does this mean something else is wrong? The fan works fine and when I used to travel 15 miles each way to work it never lost anything after use.
Hope someone has an idea or answer for me.
Regards
Matt
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Matt,
Take great care with this. The P.306 diesel is a well liked car with a brilliant engine. It'll go for over 200,000 miles with care (oil changes, coolant changes, timing belt etc).
But get the start of cooing problems and suddenly you're looking at a head gasket/head.
I've just had to fit a new (very expensive) radiator to a five year old 50,000 mile 306TD. It was hard to find where it was leaking but the core had failed close to the area you are seeing your leak.
If it is really coming from the overflow tube are you sure it isn't being overfilled and just pumping out excess? These systems are sometimes hard to fill and bleed. If it has needed topping up a lot recently was the air correctly removed from the system?
Otherwise things that could cause problems here are......sticking thermostat, leak somewhere losing pressure, head gasket problems.
A mechanic with a cooling system tester should find this problem for you.
David
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The radiator seems to be a weak point on certain pugs.
I have had to replace the radiator on both a 309 diesel and a 405 diesel, the 405 was at 4 years and 55,000 miles, which seemed a little premature.
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Brian,
You are right. I've seen quite a few radiator changes around this age/mileage, on many other makes actually. Often if they make it over this point radiators will then last ages.
The radiators in our Citroen XantiaTD (92,000mls/8yrs) and BXTD (215,000+mls/11yrs) are both original with no signs of failure.
I put this down to the regular 2yr or 24,000 mile change of coolant minimising internal corrosion. I know this was done on both of these vehicles. Or perhaps it's just luck with good or bad batches in production.
My worse radiator experience was with a Daewoo Nexia but I'll bang that on a new thread in a few days to warn (put the wind up?) owners.
David
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I have to agree with both David & Brian's comments. This is just how my first 405 started except for the journey distances and in the end required a new head.
The next 405 started again the same way @ 30,000 miles but I had learnt my lesson in that I had kept a close eye on it from new, got the cooling system checked out immediately, when it was not that, plus overfilling and poor bleeding had been eliminated the head gasket was changed.
Around the same time I had heard that the quality/type of the antifreeze you use could affect this. The product recommended was Comma Coldstream which I could not get hold of round here so I used the product rec in second place which was Pug Dealer antifreeze. Not another ha'porth of trouble in >100,000 miles.
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Thanks for the suggestions so far. I had the coolant changed in Sept last year when it was serviced, it gets regular oil changes (3000 miles) etc and has been a great car so far.
The leaking coolant is very clear no sign of oil contamination.
I haven't checked the thermostat so it could be getting hotter than it should before the fan kicks in.
I can see the full line at the filling point indicated with an "F" but no sign of minimum?? Should I fill it to full or is that too far.
It would perhaps be a good time to get to the garage for a check over.
Matt
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Matt
I've just been experiencing similar problems with my BX diesel (same engine as 306). David W gave some excellent advice on bleeding and I identified a dodgy thermostat which I replaced - the thing stayed shut in boiling water for several minutes, then suddenly creaked open a fraction. Unfortunately I think I was too late - it's off to the garage tomorrow for pressure tests. Like you I've not seen oil in the coolant or any other signs of head gasket damage, but I'm not optimistic. Get it checked now to avoid overheating/warping the head. You might have caught it in time. Good luck.
Chris
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Whilst I have no proof, and perhaps trade members can verify or shoot down this theory, I have a feeling that the water flow through the lower part of the radiator is sluggish, leading to sludge build-up and corrosion beneath the sludge. ( The tubes run horizontally so that any sludge does not drop into a bottom tank as it would with vertical tubes).
If my theory is correct then regular flushing and a good corrosion inhibitor should prevent trouble, but it may be difficult to flush horizontal tubes without removing the radiator.
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There is a lot of anecdotal evidence that when you get this problem you often find a radiator which tends to be cool/cold in the bottom half. This maybe supports Brian's theory.
As an addon to my previous post I have now remembered the chemical which makes the corrosion prevention different in the Comma and Pug antifreeze, its Mono Propylene Glycol as opposed to the normal Ethylene Glycol. No doubt someone will have all the gen as to why it performs so differently.
Matt has a very good question about how full do you fill it, because if the 306 is like my 405's it is very unclear, and the owners manual was as much help as a chocolate fireguard. The cooling system had virtually no header tank or expansion reservoir arrangements and it always seemed to me that any situation where the level was too low would lead to air entrapment and then local head overheating.
For what its worth the method I used, unfortunately after an expensive lesson, was the following. Fill it to the top, ensure you have got all the air out having found all the bleed points, then firmly close the cap and take it for a blast to get the engine nice and hot so any excess coolant will have been pushed out of the overflow. Let it go clock cold and then take off the filler cap, and see what the level is. At this point I constructed a little dipstick device so that I got some degree of measure as to what was happening and how full to fill it in future when the engine is cold.
I feel the problem experienced with this engine is down to poor cooling system design by PSA, lets face it, you do not hear of the same problems when this engine is installed in other makes eg Rover, no doubt Mr L will have a view there.
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Stuart,
There is a real knack to bleeding the cooling system on these Pug/Cit TD cars after any work or water loss.
As you comment there is very little head of water, in particular with the ones without a header tank. Chris mentioned the detailed bleeding instructions I gave him on a Citroen forum...I'm sure they are saved somewhere on the PC but anyway these are the basics.
All of these cars can suffer a problem with trapped air hence have various coolant bleed points. Each model is a little different but look out for them on the radiator opp the filler, thermostat housing (sometimes two), heater hoses, bleed hose from heater hoses on top of engine, on a small hose just behind radiator (BX GTi 16V). Ensure you have found them all.
To fill/top up you need a kind of home made extra header tank so your filling water is well above the bleed points. I use a very large funnel that holds a few litres of water when about 2/3rds full. Cut the bottom of the funnel so that it is a snug fit in your filler (rad or header tank). Fill with coolant mix until bubble free coolant emerges from each bleed hole then close them in turn.
With the funnel still in the filler and about 2/3rds full run the engine at a fast idle until the thermostat opens. At this point there should be a huge dump of air into the funnel. Top it up again if required. Keep the engine running until all the smaller bubbles have stopped.
Stop the engine and then bleed at each point in turn again, take care as the coolant will scald. Then remove the funnel and re-fit filler cap.
Wait until the car is completely cold before removing the cap again and adding/removing coolant to exactly set to the full mark. To be 100% sure run the car for a few days before checking the level cold again. Now you have an accurate position to monitor from.
You can bleed again after a few days if needed....But Very Important......don't undo the bleed screws without having the funnel/extra header tank on each time. They are just as likely to draw in more air without that greater head of water.
The problem air causes in these engines is that it can collect around both the thermostat and coolant sensors, and neither will work properly in air. So it is possible for the thermostat to stay closed and the coolant sensors fail to give overheat warning. On the motorway that may be the head gasket and/or head ruined in a few miles. And that is a very familiar tale to many BX D and P.405 D owners.
Even worse than these Pug/Cit cars is the Renault Espace where the header tank has to be pulled forward and similar bleed points located with the magic funnel in use again.
David
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David,
Now you come to mention it I seem to think I got advice from somewhere to make sure that the car was facing up a slope, but I reckon your method is far superior.
Anyway it worked for another 100k, the cars have gone to a new home and my frequency of swearing has been markedly reduced.
Cheers,
Stuart
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Ethylene glycol is "traditional" anti-freeze; it is toxic. Propylene glycol is becoming more common. Propylene glycol isn't toxic and is, I believe, used as a sweetener (don't try this at home).
Both glycols will break down into acidic compounds under the effect of heat and age; anyone who wants the formulae should go and look at;
www.problemsolved.com/reference_library/HVAC_water...m
Anti-freeze mixtures contain corrosion inhibitors. Because the glycols degrade into acids over time, regular replacement is required to stop corrosion.
I think Renaults and Citroens recommend the use of anti-freeze mixtures made with de-ionized water, because of the lime-scale in most tap water.
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> There is a lot of anecdotal evidence that when you get this
> problem you often find a radiator which tends to be cool/cold
> in the bottom half. This maybe supports Brian's theory.
Are you suggesting that it's possible for the outlet from the radiator to be sludged up and restricted? I reckon if you bleed it and the air keeps coming the headgasket is well and truly in the frame.
> Matt has a very good question about how full do you fill it,
> because if the 306 is like my 405's it is very unclear
And like the BX. The 309, by the way has a proper expansion tank and is dead easy. It's my understanding that one problem with these otherwise brilliant engines is the iron block/alu head combination. Unless you are careful with the rust inhibitors the metals react and then... splish splosh.
Chris
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Hope my missus does not read this with all the talk about trapped air and huge dumps! She will reckon I have found my spiritual haven!
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An easy way to check for air in the system is to crack open the bleed valve while the engine is hot (but not running), and with the radiator cap still on. The pressure in the system will drive fluid and any air out of the bleed valve, avoiding the need for the magic funnel, and ensuring that no air can be drawn in. This works great on my 405 TD which has a screw-in bleed valve which can be just cracked open a small amount. Be prepared with a cloth to catch the hot water!
When I refill the coolant, I use a funnel with a piece of old rubber radiator hose pushed over the "pointy" end so that it makes a good seal against the top of the radiator, and will stay in place without needing to be held by hand.
In order to see the level in the radiator, I cleaned the black paint off the outside of the tank, revealing the translucent plastic underneath. This allows the level to be seen through the wall of the radiator tank, so you can check it with a quick glance. I cleaned the paint off with a fine pan scourer.
Mike Humpherson.
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Mike,
You obviously have your 405TD cooling system well sussed. Any chap who has the funnel already is 99% there.
Just a point about why I don't advise opening the bleed screws without the funnel (exta header tank) on and full. It is right to assume that mostly there should be positive pressure to force out coolant with the system hot and the rad cap still on. But sometimes this doesn't happen due to other faults in the system (slow leak etc) or a peculiarity of the individual car. Then when no water bleeds out many might shrug their shoulders and give up or think of doing it properly next weekend. In the meantime they have just unwittingly let in that gulp of air that could be the first step of cooking the head. OK perhaps a bit over cautious but that's me!
David
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These cars have a weak point in the Heater matrix, which can cause loss of coolant. and is a right B*stard to put right. the end result is the same as a leaking radiator though.
I had a similar experience with a VW Jetta, and the fault was traced to the Heater and this was replaced by VW under a recall, however the car went on to develop a problem in the head gasket after 140 000 miles, whether the two were related is a difficult call.
However I believe you only have to overheat the engine once to move the head slighty and lead to failure of the gasket, especially true with a combination of Iron Block / Ally head
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When I first used a 405 for towing I arrived home to be greeted by a pool of coolant appearing on the driveway. Further inspection revealed that the radiator had sprung a hole. Radiator replaced but why had failed in the first place. Simple logic - harder work - excess heat - more pressure - weak spot failure. But why the excess heat? The Peugots are endowed with two large fans to keep temperature in check. Come to think of it I'd never heard the fans running. An electrical check revealed that the relays for the fans were not receiving a trigger supply. After cutting into the loom I found where the three wires were spliced and the connection was corroded. I did replace the head gasket at a later date as the car did always loose a small amount of water from the radiator over a long period. I later discovered that it was actually weeping from the joints to the heater matrix. The moral to the story is check everything is working as it should!!
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If radiator etc is ok ,try changing the radiator cap, as spring can weaken allowing water to discharge. Expansion tank then overfills and coolant leaks on to road and your garage floor.
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