Hi all,

My 2006 GP 1.2 seems to be losing coolant/water at a very rapid rate, with no visible leaks.

It can go from the max point in the reservoir, to the min in about 20 miles, however last week when driving back from a holiday (around 70 miles) it never dropped that much at all.

It seems to be quite varying on how quickly the coolant depletes, but slowly getting worse.

On instructions from a mechanic friend, I have ordered a thermostat. He did not think it was the water pump as the coolant was circulating back into the reservoir after running the engine for about 30 mins. Oil seems clean, no obvious gunk under the cap or on dipstick.

Car seems to be running perfectly, not overheating at all etc. (apart from last week when I was on said holiday and the car completely ran out of coolant - bringing the issue to my attention). I also tried radweld plus, but that hasn't had much of an effect.

Searching online brings up pretty varying issues from the tank cap, to the radiotor, head gasket etc. and I cannot pin down what it could be with my very limited knowledge.

Any ideas? Car has done 50k miles.

Thanks!!

Firstly, Radweld, or anything similar is not really a good idea. It is never a permanent repair, and mostly serves to mask the problem. It can also gum up small waterways.

If coolant is being lost, it must be getting out.
A thermostat may cause overheating, which may blow excess pressure out of the rad cap, but there should be evidence of this, with steam, and high temp gauge reading.

If no obvious leaks, we have to look at the hidden areas.
Heater, inside car, but normally will give funny smell and damp carpets. Get under the dash and have a feel around for any dampness, or a sticky feel.

There is a coolant pipe across the front of the engine, these can rust out, and being below the exhaust manifold, escaping coolant will evaporate quickly, making it difficult to spot. Have a grope around, when the engine is cold.

Water pump. These tend to only leak when running, so only allow warm/hot coolant out, which promptly evaporates. It is also behind the cambelt covers, so finding that is difficult. After running the engine for a short time, you need to get under the pump to feel for damp.

Head gasket. Common at higher mileages on the Fire engine. Sniff the exhaust, not too much, try to stay alive. When running, see if there are bubbles in the rad tank. A compression test would be a good idea.

Thanks for the response, some great suggestions which I will try tonight at some point and report back!

The incosistent loss is a pointer for me...

IF its the heater matrix . Having the temp set at COLD may potentially limit flow..therefore leakage.

I has similar with a failed matrix..
I had the additional floormats..so saw no evidence until I had an issue.. and then found they were absolutely swimming in lost coolant

Quick update guys,

I went out and checked the various spots mentioned and couldn't find any leaking coolant. I did however notice it dripping and to some extent, running from the thermostat housing or somewhere in that vicinity.

Could this be the thermostat gasket needing replaced?

I also noticed water dripping from the exhaust back box(!?) after running the engine for a while

Any thoughts on this! Thanks a lot!

Housings are plastic and do occasionally crack, I'd replace the thermostat and housing. Can't remember if it has a gasket or if sealant is used.

Cheers

Ben

varesecrazy said:

The incosistent loss is a pointer for me...

IF its the heater matrix . Having the temp set at COLD may potentially limit flow..therefore leakage.

Click to expand...

Nope.

Coolant flows through the heater all the time. Setting the temp to cold just turns the air flow to cold. No water valve on our cars.

Ben D said:

Housings are plastic and do occasionally crack, I'd replace the thermostat and housing. Can't remember if it has a gasket or if sealant is used.

Cheers

Ben

Click to expand...

Housing is aluminium with one silicone o-ring.

(Tube Fittings are plastic on some models)

Maybe thinking of my old focus. I did change the thermostat on my 8v when I changed the coolant, was a few years ago but remember the pipes at least being plastic.

Thermostat housing seems a common failure point, so if there is a drip, you've probably found the issue.

When petrol burns, water is one of the results of combustion. With a cold exhaust, you will often have drops of water coming from the tailpipe. As the exhaust gets hot, the water stays as steam/vapour until it is out. This is why short journeys rot the exhausts.

Thanks guys.

I have ordered a thermostat and housing, should be arriving tomorrow and I am back at work on wednesday sooooo...

Next question, is this an easy job? I am tempted to have a go myself as my friend isn't available until the weekend and I really don't want to bus it to work!

I'm aware I'd need to drain the system first, unbolt the old housing, disconnect pipes, put in new housing, reconnect pipes and refill the system... is it as 'simple' as that or should someone with very little mechanical knowledge not attempt this? (gotta start somewhere, am I right? )

If anyone could point me in the direction of a guide I would be most grateful

Hi there,

here's an excerpt from eLearn... hope you'll find that usefull.

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

Thanks for the help so far. Thermostat and housing arrived today with part code '55202176' so I am hoping this is the correct one

Car is out of action until this weekend though!

Some pictures of the thermo for those interested...

Drain system using drain plug on NS of radiator, it will help to open the bleed screw at the top OS of radiator too and take off the cap from the tank. Bleed screw is difficult to access, snapped hacksaw blade is ideal (tip from this forum).

Once drained, remove pipes from old unit and remove old until from engine, iirc it is 10mm bolts. Make sure surfaces are clean, bolt up new unit, close drain plug and refit all pipes except the one running to radiator. Fill up system slowly by using a funnel in the radiator pipe, when you notice it dribbling from bleed valve refit top radiator hose to thermostat and close bleed screw fill up coolant tank to max and start engine with cap off tank.

My favourite method for bleeding is

Run engine up to normal temp on gauge whilst watching the level in the tank and checking for leaks, 15 mins should do it. Top up whilst running if the level drops REFIT CAP THEN SWITCH OFF. The order is important here, the car will barf hot coolant everywhere if you switch off when hot with cap off.

That should be the system free of air but to make sure, go for a short drive and allow to cool then check level again. I personally remove cap and leave overnight at this point (place on drivers seat so you don't forget), this will allow air left in there to come out. Check level next day and refit cap.

Make sure you clean all old leaked coolant off pipes etc near site of leak, that way when you check after a few days to make sure all hose unions are holding you'll see new leakage as pink deposits (assuming you use pink coolant).


Cheers

Ben

Hi GandhiMate,

double thanks here:

- one for being the 100th poster to thank me :-D
- second and most important: for the very good pictures you sent, they will for sure be used on replies in the future !!

Best Regards, Bernie

Ben - Huge kudos and thanks a lot for the in detail guide you've written up! I will be keeping that handy when I fit this at the weekend

Bernie - Congrats! Feel free to use the pictures however you wish. I'll update this thread with more photo's of the actual fitting of the thermostat on Saturday... maybe someone could use them in the future.

Cheers guys.

Well... issue resolved *touch wood*

We took out the old stat housing and put in the new one, I think from the following images it is pretty obvious where the leak was coming from.







So... The pipe (not sure what it's purpose is exactly) had completely corroded and actually snapped as we were removing it!

Hopefully this is my issue fixed, the new thermo and housing are in snugly and everything looks good. Fresh coolant is in now too!

Thanks so much for all the responses and help on this thread! I'll see you next week when something else breaks

Thanks again for the update and the pictures GandhiMate !!

BRs, Bernie

Thank you for your post regarding your thermostat.

I have been having a DTC P0300 error in ecu (random mis-firing) and have have been researching what might be the cause, so many things it could be but I believe your post may have given me some direction and insight.

My temp gauge on dash normally reads at halfway but lately has struggled to get above the quarter. When I run a DTC scan I also took a reading of engine temp and it is nowhere near where it should be.

Once I rule out a few other things tomorrow, sparks, HT leads, coil pack, air filter etc. & oil & filter change as well as a top O2 sensor, I do believe my thermostat maybe stuck in the open position, hence why my engine is not coming up to normal operating temp and may be a possible cause for my P0300 error (random mis-firing).

So, along with all these others I will be replacing this also and hopefully it may cure a few problems for me....

:slayer: :worship:

Best of luck..
after 30 months.. you have earned it