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

 

[danieldavid]

drove 10 miles, level of expansion tank on max, drove another 20 miles which would have got it hotter and its lost a pint at least. is holding it when cold. more investigating to do, the k seal manufactureres have sent me another pack, so might put it in if i cant find a leak, i thought i could smell antifreeze slightly while i was driving, so might be gassing off slightly somewhere under the bonnet, ive heard of vapour being lost from cap on expansion tank, but i dont think thats the case here.

 

[EddieJ]

You’re right I am all petrol, diesels got too much wrapped all over the engines to get at anything . Diesel thermos unfortunately suffer the same issues.
One of the pressure test kits can be you biggest friend when looking for a leak, flexi cam too. If it’s the expansion cap lid letting by, and you are running coolant, there is normally a white fuzz in the threads before you start to see staining on the outside of the bottle. I’d be cautious about the amount of rad sealer used, it’ll go for your heater matrix and you’ll miss that in a month or two.
Anyhow, good luck with it, and sure keep checking in and let us know how your getting on.

I’ve another one to look at this week, air con stopped working on it too…could be linked, could be coincidence.

 

[danieldavid]

thanks again Eddie, that coolant leak after repairing pipe might have been airlocks clearing, but i leave my heater on all the time which is fine for scotland, even in summer... if it goes cold i know theres a leak, as the temp gauge still says normal even when the water to heater core had stoped circulating.....after that one time, it hasnt lost significant fluid and still at max mark. The smell of antifreeze might have been all the leaked fluid burning off the surface of warmed up engine. ive read k seal is difficult to block things unlike radweld, ive read this in several places, i think it uses a different method of blocking holes. Engine seems fine and undamaged.

 

[danieldavid]

that pipe to the heater matrix popped offf again, tried to put it on back of engine tighter this time, its taken over 3 months to loosen. in case anyone has issues with that pipe connection and pipe is ok, i was able to refit end and tighten up the jubilee clip by only taking off the airbox and air pipe above, fiddly job, but can be done just with a long screwdriver thankfully...

ive got an abs light on, will try to clear code before mot and if it comes back replace relevant part from code, drives and brakes fine, but was looking for diagnostics software, theres lexia 3 connector with dvd, i think its all included for diagnosing all codes incl abs for around £50, does that sound the best to buy? my cheap ancient £5 interface for obd2 only does engine codes, thanks if anyone knows best value option....

 

[danieldavid]

the reason i knew it had lost water was because the heater went cold which i always leave on in case it does but i never get a light for low fluid, will need to investigate, i think theres terminals in the coolant reservour, in case anyone knows most likely cause of the warning light not coming on, if i can fix that i wont have to have my heater on in the summer....

 

[EddieJ]

There is (usually) is a sensor in the bottle, if your reservoir is empty and not showing a condition on the dash, if you unplug it it should flag up on the dash that you need to check the coolant level. That will tell you your wiring is okay and there is an issue with the sensor. It may be that the sensor has failed closed or the two prongs have gathered enough coolant goo to maintain a closed circuit. You could try cleaning before heading down the road of replacing. The sensor is tight push fitted to the bottle and seals via a rubber grommet. It can be pulled out with reasonable force but pulling as close to where it meets the bottle to try and avoid damaging. Silicone grease is your friend for refitting.


Common abs fault areas below,
but could be more, abs pump, abs relay, wiring faults. Obd reader that can show live data from wheel speed sensors will very quickly help.
Big big tip, when rotating either of the front wheels to read speed sensors the door locking can activate, leave the windows down when testing….you don’t want locked out with the key left in the ignition.



Front abs setup as above, clamped to the back of the steering knuckle (with an M6 hex that loves to rust, I changed to M6 hex stainless).
corrosion can build up behind the sensor ‘leaning’ it in as well as muck and debris collecting on the magnetic ring and causing wear to the sensor face or and or mag face. The front sensors are not handed, ie same fits left or right.





The rear abs setup has the mag ring on the hub, upper pic with the sensor protruding through rear frame / disc dust cover.
The little silver clip circled above corrodes and disintegrates and the added corrosion on the mounting point causes the sensor to again lean in and wear on the magnetic ring ring. Also crud build up can wear the ring/sensor faces. The ring can be changed as a standalone item, but to do so you have to pull the hub off and in doing so the bearing inside inner race will be left on the hub shaft, meaning new bearing. It works out better in the long run to buy a full rear hub per top pic if needing to change the ring. Hubs are not handed but on the rear the sensors are.

Re obd scanners, many out there and many will assist you. I personally use the Launch CRP123e for such, I can lift a wheel and watch live data for its rotational speed to aid diagnosing abs issues along with a heck of a lot more.