large coolant loss around back of engine on 2.0 diesel

[danieldavid]

hi Eddie, Petro or anyone who has advice, looked through the 10 pages of entries on forum under coolant but seem to be for petrol not diesel typically, hence new thread. had a coolant leak last year, on forum, from front, possibly egr, solved with k seal, lasted 6 months till recent hot weatyher, smelled coolant while in traffic. presently it takes about 1.5L of water in 5 mins, even with engine off and expansion tank cap off without pressurei can hear it drippping onto under tray etc, attached a pic, the brown water is pooled in middle of pic. need to fix before using again. Does anyone know what its likely to be on diesel, whether theres a vulnerable pipe at back, or likely to be thermostat housing. i cant think its any risk of block damage as temp hasnt gone over 90, though fan going on. 1.5L seems to fill it, so must be litres in it still though wont be using till fix. Ive heard these take 8 to 10L of coolant, 1.5L missing i assume, possibly more, thanks for any advice

 

[EddieJ]

From you pic and info I’d be on the thermostat housing. You can spend a few £ and buy a pressure test kit to confirm. Would recommend really good flushing of the system too to get all the muck out.
The end where the hose goes on, on the smaller ones suffer from degradation and the hose starts to leak, pop in rad weld and get a wee while longer then the rad weld lets go of the cavitated bit only now as a big leak
As well as splitting of course.

 

[danieldavid]

many thanks Eddie, ill try to strip it out tommorow, wasnt sure if the diesel and petrol had similar piping to rear of block, i found a video by the carflix person on youtube who struggled to swap one over, will give a try tommorow, i realise where lots of water is is on the transmission housing, so might make sense its leaking very close to the thermostat housing, good advice thanks. Its emptyimg 1.5L in around 5 mins then finding a level, i realise now that both pipes fron expansion tank are going to radiator, not to engine, that must be why its not overheated above 90, the thermostat would be in the housing, if leaking from there, it must be high up enough to hold most liquid, i noticed the heater went cold, hopefully it hasnt got too low and everything works once i replace, clean out and refill. I was going to try to swap it out without taking batttery & caseing out, do you know if this is feasible or if i definitely need to take the battery out to get to the thermostat, many thanks

 

[danieldavid]

hi Eddie, started stripping parts around the thermostat and i can now see the leak, theres a jet of water coming out about an inch or two further back than the thermostat housing out of the pipe that points downwards slightly out of the thermostat to the rear, its at 9 oclock on the first diagram on the ebay item attached, just ordered it this morning but guesiing i need the pipe instead, thermostat will be fine as a spare for future as ive got 2 rczs.

https://www.ebay.co.uk/itm/336586112396

i thought this was the dreaded crossover pipe thats an extremely complex and difficult job to reach, but now realise its the pipe coming off of it going to the heater matrix. the below thread has diagrams of what it likely is, no one has responded to it, but looks like ive got the same issue, i think its pipe no 11 in this thread.

HDi Coolant Leak - Identify the Pipe

Hello All, First post, glad to be part of the community! Just downloading the 14GB workshop manual, but in the meantime, I'm hoping for some help. I have a HDI 2.0. The other day, it dumped half a tank of coolant onto my drive... Leak is towards the rear of the engine. I have spotted the pipe...

www.peugeotrczforum.com

i managed to squeeze my hand in and reach the pipe, it completely fell out with coolant rushing everywhere, i thankfully managed to squeeze it back on and filled expansiopn tank and its no longer droping visibly. im going to have to try to work out how its fastened on. i think from diagram its held on by part 70 which might be one of the old fashoned circular clips, i wonder if i might be able to get a jubilee clip on it.

if anyone has had this issue before, but looks like its come loose under pressure rather than burst.....i think

 

[danieldavid]

phoned peugeot, they reckoned they would replace with a jubillee clip now adays as those old circular clips that were tightened with special pliers are obselete, will see if i can manage to replace with a jubilee and tihten, and can see if that was the only leak. it wasnt losing liquid until days ago. hope that crossover pipe never goes at back of engine, guessing would be very difficult to swap over without renmoving the engine

 

[danieldavid]

i realise these arent old spring hose clamps, so i dont think a jubilee would fit, might have to think of another way of fastening it on. in case anyone has had one of the heater matrix pipes push off under pressure and had a solution, welcome to let me know, thanks

 

[danieldavid]

think i might have found the pipe on ebay. no 11 on the diagram in thread above. The fittings are plastic so i cant just put jubilee clips in, ill need to try to work out why its pushed off and if it can be tightened. this is the ebay item with the clips each end of the no 11 pipe, in case anyone has similar issues or knows how to tighten

https://www.ebay.co.uk/itm/116191824811

 

[EddieJ]

Hi David, sorry haven’t got looking in for a few days.
Just make sure and have a good look at the stub the pipe goes on, through heat cycles and cavitation the end of the pipe crumbles away (be sure to recover as much as you can, if it has). Not quite the same thermostat housing but similar enough to show what I am on about. Both ends of yours are like barbed clips, and either can be degraded, .

Just as a quick add in, you can nearly do it with the battery still in, and all the air pipes out, but it’s very tight and doesn’t give much room to look at whats going on. Half an hour will pull the battery and tray out, rem the hidden bolt for the tray behind the passenger inner wheel arch liner.

 

[danieldavid]

many thanks for replying Eddie, just saw your post, earlier today i had a go at trying to work out how to fasten the pipe back leading to heater core, im pretty sure it is the no 11 pipe on the 2.0, i had a look and pipe was fine, the pressure had forced the pipe off the pipe at the back of the engine, on that other thread i sent days ago theres a pic of where the pipe joins the pipe on the engine at the back, i didnt disconnect anything off the thermostat to check any pipes, as the one that popped off goes onto a connection on a seperate big pipe across the rear of the engine that itself connects to the big lower thermostate rear connector. but when i got one of my phones in with light on i could see the existing jubilee clip, i loosened it and pulled the pipe back on and tightened it well, so im hoping this will solve. yes, i thankfully was just able to do with battery in situ though had to take the clamp off the thermostat connected to the fuel lines. will see if it is ok now, only ran for a few seconds and water never dropped, will need to take the undertray off to drain it fully some time i think, threw in a litre of antifreeze though should get to that well before winter so water doesnt corrode anything. yes its a really tight space to work in, thankfully not the pipes at back of engine block... in case anyone else has similar issues with water loss around thermostat, it might be also the pipe connectors just blowing off, or the pipes. the pipes are on ebay if needed but about £50 each or a pair.

ps thanks again for advice, i should buy a snake camera, would make diagnosing so much easier. its so difficult to find where leaks are coming from at times, the thermostat coming in post was reduced on ebay for only £25, will be ideal as a spare as the housings seem to fail as you say, mine might be originals on both cars.

 

[danieldavid]

ps, eddie, i think youve got petrols not diesels, and diesels run colder, but my fan never comes on though it has recently when it lost some coolant from above issue which i stopped using it the same day as precaution to protect it, but in winter here up north, would you expect the fan to never come on in winter, even in traffic, im pretty sure the pipe blowing off is not a pressure leak from head gasket, just a heat and thermal expansion pressure issue that should be contained by system, but if the fan does come on eventually (when it had lost some fluid) is it likely its working normally? ive read if the fan never comes on, thats definitely an issue with fan/relay