My c4 is playing games I don't like

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

white exec wrote:
13 Nov 2018, 20:46
Try parking up, and leaving a sheet of cardboard/paper under the car, to see whether any drips show up.
If nothing shows up, run the engine and allow it to get fully up to temp, to see whether heat expels anything. (Cooling engines can actually suck in through leaks :cry: .)

Will do. I'll put a cardboard sheet on the plastic under the engine and drive it like that for a few days if it doesn't rain. I think that's the safest bet :)
white exec wrote:
15 Nov 2018, 09:06
Normal working pressure of cooling systems is around 1.3bar. I wouldn't go anything much beyond that for test purposes.

Thanks for that info!

I don't have a pressure tester. My mechanic has one, but he's booked for a week so I'll keep trying to find the fault myself. He did say he would take me in if it's necessary, but I don't think it is.
moizeau wrote:
14 Nov 2018, 21:21
Rad on the condenser/front side, like you say the engine is hot and will evaporate. On a 307, similar, you can just get you hand in. Use toilet roll to check, it finds the smallest of weeps. Just done the rad and condenser on my 407 and there was half a hedge stuck between them, and some feathers. The fitting of AC stops you seeing the front of the rad..If the rad could be the problem, you could remove top and bottom hoses, block them up then use the header tank breather to pressure test in situ, not sure what pressure, but a bike pump with an old tyre valve should do the trick


I'll take that into consideration. That's actually a pretty good idea for testing :)
Thanks.

Simple76
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Re: My c4 is playing games I don't like

Post by Simple76 »

I would advise against a radiator stop leak. They can cause all sorts of problems they are not a real long term fix. I would suggest checking round the outside and underneath radiator coolant normally leaves a tell tail sign.

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

I too advise myself against anything to be added to the coolant.
I'm a mechanical engineer and my experience tells me that nothing can be fixed simply. It's either a proper job of stripping and repairing or a cockup.

My friend tried to plug a hole on his underfloor heating by adding that leak stopper to the system. It did stop the leak, but it also lowered system's efficiency by a lot. That's undoubtedly what it would do to my car. I don't know to which extent but to some, definitely.

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

It's 3°C outside and I've been monitoring the engine temperature using TorquePro.
Well, VTS was always a slow heater, c4 was the fast one. But it's not any more.
It took him good 5 kilometers to get up to 80°C and didn't go much higher. If I pressed the throttle somewhat more(no flooring, normal acceleration), it would get up to 90-92°C, but would get down to 80-85°C again. When idling, it would sit at 80-85°C instead of the usual 95°C. And also, it never reached 100°C and opening temperature for thermostate is 105°C.

Could a faulty thermostate be the cause of the car losing coolant?
Mind you, I've driven it for about 8-10 kilometers, not more.

And also, can the thermostate cost 250€?? What the, on my previous car thermostate was like 20€...

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white exec
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Re: My c4 is playing games I don't like

Post by white exec »

Sounds like the thermostat misbehaving (remaining leaky/open): temp climbs when you maintain power, but then falls off to an unacceptably low figure.
Apart from main dealer price, look at Mister Auto (PSA owned) for the 'stat. Many are one-piece with a housing, which explains the higher price.

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

Nothing pops up at Mister Auto. For now, it's cheapest at the dealer :mrgreen:
I'll drive it a bit more(30 km) tomorrow and see if it's any different. It could be because I had the heater on high(cold feet :mrgreen:) so it was stealing some of that heat from the engine.

If it is a faulty thermostat, I really hope replacing it would solve coolant loss problem.

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white exec
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Re: My c4 is playing games I don't like

Post by white exec »

Not listed on Mister Auto, as you say.
If 'stat is sticking (sluggish to open or close completely) it could explain coolant loss.

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

Interesting, thanks :)
I've driven it 15 kilometers now, and after 10-ish, things seem to be normal.

moizeau
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Re: My c4 is playing games I don't like

Post by moizeau »

If the stat is playing up it would show itself in odd temps, but you would see high ones as well. I guess that would be when the coolant loss occurs (Chris could you confirm that could be the reason behind loss you mentioned, if not I need educating further (again)?)
No idea what car you have, but is it similar to this
https://www.piecesauto24.com/citroen/c4 ... ries[]=316
On another note...did you see the footba....?

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white exec
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Re: My c4 is playing games I don't like

Post by white exec »

Can you post your VIN, so correct 'stat can be identified, if needed?

A 'stat which has gone leaky (eg a torn sealing washer) can give depressed temperatures when driving normally, which will only get up to somewhere near normal when a good bit of right foot (ie fuel) is used - eg a prolonged hill climb. Thereafter, temp will fall low again.

If a 'stat is jammed shut (or nearly shut, so it can't open) there can be localised boiling in the cylinder head/block, which can generate steam, which expels coolant. This will be aggravated by a failed (leaky) pressure cap, allowing boiling at a lower temperature.

If a 'stat is stuck open (or completely missing) engine will be VERY slow to warm up - especially in the case of a diesel (more-so going downhill) - and may never reach proper operating temperature in cold weather.

An indication of whether the 'stat is working can be got from starting the engine from cold, and feeling the pipework leading to the cabin heater. This should warm up quite quickly, leaving the large pipework to the radiator cold, because the 'stat shuts off the rad circuit until the block is up to working temp. If both sets of pipework warm up at the same rate (and this will happen very slowly), the 'stat is leaky/stuck open/missing.

moizeau
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Re: My c4 is playing games I don't like

Post by moizeau »

Thanks for that Chris, I thought I was sufficiently educated until the last bit about checking the cabin heater pipework. I will remember that, thanks.

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

I have an access to service.citroen(free part, anyway) and I've found thermostat's code "98 086 469 80".

I've driven it again this evening and it seems to be fine. It takes about 10-15 kilometers for temperature to get stabilized and from then it acts normal. I guess it heats up slow because my heater is set to high.

As for the football match... They say that the Queen fell into a depression this summer so our team didn't want that to happen again 8-[ :-D

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white exec
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Re: My c4 is playing games I don't like

Post by white exec »

10-15km is an excessively long distance for temp to reach normal, particularly a petrol one.
The setting of the cabin heater won't make a significant difference, as its heat output is small compared to that of the engine block.
The symptom points clearly to a failed thermostat.
Hope you can find a reasonable price for one.

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Cutac
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Re: My c4 is playing games I don't like

Post by Cutac »

Alright then, I'm off to find a thermostat. Which manufacturer does OEM?
I'll take the VTS to compare the heating up process, it's thermostat is a year old and thus probably fine.

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Re: My c4 is playing games I don't like

Post by Cutac »

Yeah, it's not closing, temperature at the lights drops down to 60-70°C.

Facet for 55€ or Magneti Marelli for 90€?