Peugeot 207 overheating issue

[JmatthewB]

My partners 1.4 207 was serviced the other day at an independent garage. Today on her way back from work she calls me saying the cars temperature gauge is in the red with a stop message on the dash. I told her to turn off the A/C, put the heater on full and see if the temperature goes down, which it did and she made it home. I've just checked the coolant reservoir and it looks very empty (couldn't really see in the dark).

The invoice from the service includes antifreeze put I don't know if they flushed the system or just topped it up. Going back over a year the coolant had been dropping a little so we put some K-seal leak repair into the system and the level stopped going down which we checked fairly regularly. But is there a chance that if they have flushed the system the old leak has been aggravated?

When it was serviced one of the items they replaced was a thermostat, as the temperature gauges hadn't been giving any readings at all for a while. So I assume they'd have had to drain the coolant to do this?

What would people advise to do? Fill-up the coolant and take it back to the garage?

Edited by JmatthewB on Wednesday 1st December 19:58

[paintman]

I would expect it to be drained & refilled with the appropriate concentration of antifreeze.

Changing the thermostat would need at least a partial drain down of the system.

Needs to be bled when refilling as Peugeot use bleed screws in their systems which need to be opened to allow air out.

If anything hasn't been properly reconnected then the pressure in the system will find any leak points.

Antifreeze has a 'searching' effect & it will find any weak spots - which may include your K-seal 'repair' - and leak.

K-seal is intended to bung things up. Which can include small passages in the cooling system.

Look for any obvious leaks.

Top-up & return to garage.

[Maxdecel]

JmatthewB said:

..........Going back over a year the coolant had been dropping a little so we put some K-seal leak repair into the system and the level stopped going down which we checked fairly regularly. ................as the temperature gauges hadn't been giving any readings at all for a while. ........

The first loss of coolant likely did for the thermostat in the first place, filling with new coolant has rediscovered the original leak. Leak stopper is not intended to be a permanent repair.
Returning the engine to it's correct operating temperature (new stat.) will also exacerbate any weakness that exists.

[JmatthewB]

I rang the garage this morning and they're coming to pick the car up.

[JmatthewB]

So it was just the coolant reservoir that was empty of coolant, the system was topped-upped, bled and pressure tested with no signs of any leaks.

Presumably the overheating was caused by the low coolant level but why did the level drop without any leaks? The garage had replaced the thermostat housing as they had noticed a leak from there, could they simply have not bled the system properly? Could a faulty temperature sensor be causing the coolant too get to hot and escape as steam through the coolant reservoir?

[paintman]

We've had various Pugs - 205, 306, 307 - & they can be a bit of a pain to refill even using the bleed screws to get as much air our as possible & it's recommended to use a header tank on top of the expansion tank.
Old plastic bottles with the bottom cut off are a favourite for diyers just need stuff wrapping round the neck to fit the expansion tank neck.

4th pic down in this link shows what I mean (on a 306GTi) www.pugaddicts.co.uk/2012/12/guide-peugeot-306-gti...

Hopefully the garage have resolved the issue, but check it when cold for a few days & after that I'd suggest checking at least once a week as part of your normal checks.

[JmatthewB]

So the garage topped up, pressure checked and tested and found no faults. But again today it’s overheating and the coolant reservoir looks empty again.

[GreenV8S]

JmatthewB said:

So the garage topped up, pressure checked and tested and found no faults. But again today it’s overheating and the coolant reservoir looks empty again.

In that case you need to ask the garage to take another look at it.

[paintman]

Any evidence of coolant leaks anywhere in the engine bay?

You had a coolant loss issue before you put the K-seal in & if your coolant loss rate is much the same then possible your K-seal 'repair' has failed.

Be an idea to have the coolant checked for the presence of exhaust gases.

Edited by paintman on Sunday 5th December 18:08

[JmatthewB]

paintman said:

Any evidence of coolant leaks anywhere in the engine bay?

You had a coolant loss issue before you put the K-seal in & if your coolant loss rate is much the same then possible your K-seal 'repair' has failed.

Be an idea to have the coolant checked for the presence of exhaust gases.

Edited by paintman on Sunday 5th December 18:08

There’s no obvious signs of any leaks. And the pressure test didn’t show anything either.

[GreenV8S]

JmatthewB said:

There’s no obvious signs of any leaks. And the pressure test didn’t show anything either.

That not what was suggested. You should carry out a block test aka sniff test to check whether the head gasket has failed into the cooling system.

[paintman]

^^^^ What he said.

There MAY be a small leak(s) which will only show when the engine & coolant are up to full temp.
Possibly hg or a cracked head.

[TV200]

I had much the same recently - I gave everything a good rinse under the bonnet and then topped the system up. I then ran it and looked afterwards as to where the coolant had leaked. It turned out the only think covered in crystals was the expansion tank. I changed the expansion tank and presure cap (all fairly cheap online) - I think it was probably just the pressure cap, but the tank looked to have small cracks in it. No problems since.

[JmatthewB]

The garage have had it in twice since and can't diagnose the issue. They've pressure checked, fitted new thermostat, checked the coolant for exhaust gases, checked the water pump. All fine.

Partner brought the car back on Friday, I looked at the coolant level and it was slightly under the middle line. She went to work and back again on Monday and the level had now increased to above the max line (checked 3 hours after so should have been cold). Now this morning it has overheated again but this time no hot air was coming out of the heater vents (previous times this had helped to cool the car down).

So I'm guessing either an air-lock or other blockage in the radiator that's stopping the flow of coolant?

Edited by JmatthewB on Tuesday 14th December 08:40

[GreenV8S]

An air lock would explain some of those symptoms, and wouldn't be unusual if it has run low.

Three hours isn't enough for the engine to fully cool down so you may still be getting a slightly misleading reading. If it happens again it would be worth making another check the next morning to see whether that's a permanent change or just heat related.