Steam Vapour From Exhaust But No Other Hg Symtoms

[MrMoonstone]

Hello, I'm making my first ever post here on this forum and I really hope that the knowledge and expertise I have already read will help me make sense of an issue I have with my particular C5.

 

My C5 is a 2005 facelifted mk1 2.2 HDi 138bhp Exclusive estate auto with 160k miles.

 

I believe I have cooked the head gasket but the symptoms don't match my experience with older diesel and petrol CX's / Xm's and I would appreciate confirming my thoughts with those who know the
C5 well, or certainly better than me, as I have only owned the car for just over x2 happy years with no issues.

 

On the way into town on a reasonably quick moving dual carriegeway it started warning of excessive engine temperature so I stopped immediately and checked the rad which was cold so likely an air lock?

I limped the car home later after allowing the engine to cool right down and checking water levels and the temp gauge seemed to yo-yo from normal at the 80 or so vertical to max in seconds so I wasn't even sure if a sensor was sending a stable signal?

 

On checking the car a few days later, as a precaution I fitted a new thermostat and bled and levelled the water and the engine starts and runs sweetly and stable. The water doesn't drop in volume that I can discern and doesn't pressurise the expansion tank, the oli is clean and its level is on the mark and the cap doesn't show moisture build up nor mayo creaming in the oil nor does the dip stick. Outwardly the car seems fine. However it has started to steam white clean water vapour out of the exhaust and hoping it was just trapped water in the exhaust I have sat the car idling for around 20 minutes and the temperature seems to sit at around 70 and not go any higher - it doesn't even seem to get hot to get the fans cutting in. I have tried a dose of K-seal in the hope any minor water to air leak could be highlighted but this has made no difference.

 

What am I missing, is this a small head gasket failure or is there another way water can get into the exhaust via for example the induction / exhaust pipework autobox heat exchanger or turbo etc.

 

I can get help from my son to change the head gasket but have read online it's a tricky job and the cost of maybe gettting a new head matches a whole engine to swap out that would require similar time to remove/fit and could be a better option using a known quantity donor. Is the gasket reapir job as bad as some say online?

 

For a fair price locally I can get a full bar the cat 100k 2.2 HDi engine but it now turns out it's a 172bhp twin turbo version - is this compatible with my car / loom engine management? I need a to gain a lot more knowledge about whether this engine would fit/work?

 

Any advice/guidance would be most welcome.

 

Charlie.

[paul.h]

Welcome to the forum.

 

First thing will be to check the temperature sensor since these often fail on Citroens giving a false high temperature indication. A new 1 is only around £20. If you have a code reader that gives live data you can see what temperature it is giving, should be around 15°C before starting the engine first thing and then gradually rise to around 83°C when the thermostat should start to open and the radiator top hose warm up. Then possibly get to around 90 ish with the fan starting at about 96°C if it gets hot enough. Without the code reader the engine temp gauge will be just below the mid point when the thermostat opens.

[MrMoonstone]

Thank you for the welcome Paul, It's nice to know I can talk with someone who knows these beasts better than I?

 

I think events are overtaking me with my C5 now. As I haven't touched the car for over a fortnight after typing the post above I have looked at the car again afresh.

 

Whilst the car started instantly it cut out and struggled to restart and did after running on about 3 cylinders but is idling happily again. It now seems the symptoms have had a chance to worsen and now look like a nailed on gasket failure as the exhaust steaming is far more pronounced and the sucker punch is a white frothy film present in the expansion header though not it isn't pressurised (yet). It must have started to go when I was looking at it last and it now needs full mechanical attention. I want to make a fix as I value the car and haven't seen one with quite the same spec even spending lots of £'s and it drives beautifully and still has a month old MOT.

 

The current situation brings me more to the second query in my first post - what is the compatibility of the 172bhp 2.2 engine I am interested in - is the change purely down to the twin turbo and manifold? Do I attempt an 'upgrade' to make it run 172bhp with likely engine management incompatibilities and potential unsuitability to a highish mile but fully working autoadaptive gearbox or can I plug the 172 head/block in to run in my C5 as is. Does anyone know the differences between the 138 and 172 2.2 engines and whether I can make this engine available to me work and even whether they physically would plug in as replacements to one another?

 

I can get access to a Lexia diagnostic laptop although it may be a case of the blind leading the blind using it!

 

Thanks, Charlie.

[paul.h]

I have no idea if the 2 engines are interchangeable but you could check the parts diagrams to see if there are any common bits. Register on the service.citroen site as an other professional non emergency services and as a member of the Citroen Owners Club http://service.citroen.com/do/changerParametres

[MikeLane]

It sounds like a head gasket problem to me.

The Haynes manual (4745) gives instructions how to change it and this should be a cheaper and easier option than trying to shoehorn in another engine. Get the manual and have a read.

(The manual doesn't include the 2.2l version of the engine but it only differs in having a 8mm longer stroke so...)