High coolant system pressure, exhaust gas leak?

[kingy1912]

Hi everyone,

Currently having issues with high coolant pressure and disappearing coolant. There is no smoke or steam evident from the exhaust just disappearing coolant and high pressure. Don’t notice any bubbles feeding back up the system but the header tank was replaced due to oil cooler leak. The inside of the tank is darkened and has a black film inside of it. When rubbed off it looks suspiciously like exhaust soot but the coolant does not really have a smell of exhaust gas coming from it.

Garage were the first ones to mention it as we found a leak in the hose coming from the header tank. Hose was replaced but still coolant disappears. We have now noticed coolant leaking from the seal on the radiator degassing hose that plugs in to the header tank. I suspect this is simply because of the higher pressure in the system.

Garage suggest an engine overhaul is best and I would normally agree but it has 370k on it and not long to go until we need to move it on.

I am currently swaying with using some of the KSeal Uktimate in it. However the overwhelming number of reviews are positive but there is a number of them suggesting it either made their problems worse or blocked their hoses and matrix up.

I am wondering if anyone has used the stuff in the HDI engines and know how it reacts?? I’m thinking that maybe a full bottle is too much for some coolant systems and folk are having issues because there is too much in the system?

Also seen steel seal but the reviews look worse for that.

Thanks

[oilyrag]

Adding K seal & the like - once done there's no going back and seems either temporary or disastrous! Would suggest cheaper options of replacing the filler cap to make sure that the system is running at the correct pressure and secondly using a simple Radflush & Radweld type product. If you have an overflow tube then divert it into a drinks bottle to see how much you catch.
If you still have concerns you can get the coolant checked for products of combustion - assuming that any possible oil contamination from the oil cooler change was dealt with at the time.
A further thought is that the system may be being over-filled - run it near the minimum indicator and see what happens.

[kingy1912]

Adding K seal & the like - once done there's no going back and seems either temporary or disastrous! Would suggest cheaper options of replacing the filler cap to make sure that the system is running at the correct pressure and secondly using a simple Radflush & Radweld type product. If you have an overflow tube then divert it into a drinks bottle to see how much you catch.
If you still have concerns you can get the coolant checked for products of combustion - assuming that any possible oil contamination from the oil cooler change was dealt with at the time.
A further thought is that the system may be being over-filled - run it near the minimum indicator and see what happens.

Hi oilyrag,

Thanks for replying! I have been put off the idea of using Kseal ultimate but I am thinking about trying Radweld plus by using half a bottle first to see what happens. I have seen a lot of people having better success when using less. It does appear that if it’s not measured for the system size and there is too much it causes issues. I’ve seen folk saying they have a thin gel like coolant after using these products. I have used some in the past and never experienced that kind of issue tbh.

Anyway as far as overflow goes there does not appear to be one unless it is the same as the degassing tube running from the top of the radiator to the header tank. When there car is running and given a bit of gas there does not appear to be much coming from it.

I filled it yesterday with about a quarter litre of fluid and so far after about 200 miles it has not used very much if any coolant at all. However there is still a lot of pressure there and definitely more than I have noticed before. 

I am due to pick my K9 version up from Citroen later after warranty work so will look in to buying a new cap in case it is defective. It does not appear to have anything coming out of it so either the pressure is not high enough to release via it’s valve or it is defective.

When the oil cooler was replaced the system was flushed and refilled. However going on the basis of how much oil was stuck around the top of the header tank it’s wasn’t very effective. That is one of the reasons I had it changed.

The garage also replaced with a grey/black coloured coolant that Citroen supplied so it is hard to tell if the coolant is actually picking anything up due to the colour. There is also no where near enough fluid been added to water this down as the only OAT antifreeze I can find anywhere appears to be pink in colour.

Also tried running it near the minimum mark but you can only gauge it when you release the pressure or wait for a full cool down. While it is hot the pressure is pushing the fluid from the min mark to the very bottom of the header tank. You can see about a half to one inch of fluid in the bottom where the hose comes out the bottom. Once the pressure is release it comes back up to the minimum mark. So it appears to sometimes use coolant but other times it does not. The system has been checked for leaks and none can be found. I would assume if it was leaking that pressure would not built the way it is as when the thermostat housing and cooler were leaking pressure was minimum.

I fear it really needs further investigation and at 370k it’s maybe better to retire her altogether. A full strip down and the money required to investigate it wouldn’t really be worth it.

I also thought about the EGR cooler but I have no idea if exhaust gas and coolant would have a chance to mix via this source???

Engine runs fine, accelerates fine and idles smoothly considering it has 370k on it. Absolutely no smoke or sweet smells from the exhaust either so if it is burning coolant it would appear to be minimal at worst.

Thanks

[oilyrag]

It's very difficult to get rid of oil contamination from the cooling system, and the remnants may be what you are seeing. Some folk suggest washing machine tablets, but that attacks aluminium, so maybe not so good!  If the pressure seems high (really hard hoses when hot) the it could be the cap - not sure what it is rated at on yours - maybe 14psi?  You'd expect changes in level due to expansion/contraction and filling to minimum,cold would be best.
Good luck!

[kingy1912]

Yeah I’m not completely sure what the pressure should be and finding the data is hard. If I stop the car and screw a few turns it hisses like mad. If I were to scre it off it pops up like fizz from a shaken bottle of fizzy juice and spews out the side of the cap. I’ve never seen that in any of my berlingos to be honest. I’ll replace the cap and see how that goes but for now the coolant use seems to have stabilised.

[Kieron G]

After I changed head gasket on our DW8 the residual oill seemed to collect in header tank for a long time. It looked really bad, I kept absorbing the top layer with rags and eventually I got nearly clean coolant. If oil cooler was defective the situation might be similar. 370.000 miles is really impressive. Ours has a mere 200,000. I'm glad I took the trouble to change the gasket and reset valve shims as there was no apparent wear on the bores and the valves hardly needed grinding in.

[kingy1912]

After I changed head gasket on our DW8 the residual oill seemed to collect in header tank for a long time. It looked really bad, I kept absorbing the top layer with rags and eventually I got nearly clean coolant. If oil cooler was defective the situation might be similar. 370.000 miles is really impressive. Ours has a mere 200,000.  I'm glad I took the trouble to change the gasket and reset valve shims as there was no apparent  wear on  the bores and the valves hardly needed grinding in.

To be honest they do that no problem my 2010 B9 has 354k on it all used for private hire. My newer K9 has 62K but I’ve had issues already with water pump bearing, strut tops and the adblue injector. Now it’s sitting in Citroen waiting on a driveshaft that is on back order. Thankfully all the work was done under warranty. The only thing I would say is it burns about 1/2 a litre of oil per 1k so to counter this issue with the newer one I have halted my oil change interval. It really does run very well and over the last 5 1/2 years it’s had 13500 quid spent on it all in on total care and maintenance. Servicing, faults and repairs, tyres etc.

So far the coolant seems fine but I changed the header tank because the oil coming from the cooler got stuck all around the top of it. There is a funny little bit at the top which means I could not get in to clean it so I decided best option was to change it as it looked horrendous.

I got a bottle of Radweld plus and it treats 21 litres so I just put a quarter bottle in. Took it for a 30 min drive at various speeds. Brought it home and the coolant level was resting just under the top of the cap. I topped it up before I left to just under the max.

The engine is also running even smoother than before but that could just be my imagination lol

[oilyrag]

Yeah I’m not completely sure what the pressure should be and finding the data is hard. If I stop the car and screw a few turns it hisses like mad. If I were to scre it off it pops up like fizz from a shaken bottle of fizzy juice and spews out the side of the cap. I’ve never seen that in any of my berlingos to be honest. I’ll replace the cap and see how that goes but for now the coolant use seems to have stabilised.

Do avoid, unless you like Hospital food, unscrewing the cap when the coolant is hot - the water is well above boiling point and will cause you serious damage!!

[kingy1912]

Yeah I’m not completely sure what the pressure should be and finding the data is hard. If I stop the car and screw a few turns it hisses like mad. If I were to scre it off it pops up like fizz from a shaken bottle of fizzy juice and spews out the side of the cap. I’ve never seen that in any of my berlingos to be honest. I’ll replace the cap and see how that goes but for now the coolant use seems to have stabilised.

Do avoid, unless you like Hospital food, unscrewing the cap when the coolant is hot - the water is well above boiling point and will cause you serious damage!!

Yes of course that is why I screwed it off a little at a time. However I have had 2 berlingo prior to this one and they have never held pressure in the cooling circuit like this?????

[kingy1912]

Hi all,

I mentioned a few months back that i was having issues with exhaust gas in the coolant and coolant disappearing. The car has not been used much but is going to be required to get back to work again. I am looking to see if anyone has had experience of the EGR and cooler on the 1.6 blue HDI?

Engine still runs smoothly considering the mileage, no smoke/vapour from the exhaust or smells either and also no puddles under the car. The cars also heats and cools np and no sign of overheating. I strongly suspect that it may be a leak coming across from the EGR to the cooler.

Coolant system has had a new cap fitted to the tank and no change, no water in the oil and no oil in the coolant either. System still over pressurising, also holds pressure for days after not being used although it is not a huge amount more a kin to opening a bottle of fizzy juice.

Added K seal and no change has been noted.

I feel the only option is to get it stripped and check to see if the seal between the EGR and cooler is leaking but the garage is quoting me a hefty figure of around £300 to strip and inspect. A fair amount considering we don't really know the issue. However on the basis that it does not seem to be showing too many other knackered EGR/cylinder head symptoms i am looking to see if anyone thinks it is worth starting here.

If anyone has any experience of this kind of issue then some advice would be appreciated.