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