Coolant leak.. Thermostat housing? (part no please?)

[guysy]

Well my grandad who also has a 1.2 calls me to tell me he has coolant pissing out, after a while with a torch that put out as much feking light as a candle in a jam jar we both with our minimal mechanical knowledge thought it was a head gasket problem, looking under the air box (1.2 engine) i could see coolant underneath and resting on the gear box...

The only thing that made me think oh maybe head gasket was looking underneath i saw steam in the same place below the air box, i thought it was coming out of the engine block but after some research on here i think its a f**ked gasket on the thermostat housing... if it is that's good because he was expecting a large bill...

So i was thinking clamp the hoses (is this ok?) then take them off and inspect the housing...

A few questions:

Anyone else think the housing is likely to be the problem?

Just for info are the d4f engines common with head gasket failure

If im changing the housing shall i change the thermostat too?

Does anyone have the part no for the housing please?

EDIT: nicking a picture from another thread on here... just below the housing was where i saw the steam so it seems obvious now where the problem is... i think

 

[MicKPM]

The D4F is normally a bomb proof (Mechanically) engine but is known for the thermostat housing matey... Change this with a new, genuine item (Around £35 iirc) and fit a new stat to (between £8-17) then refill and bleed the coolant circuit. The housing is plastic and so eventually goes brittle allowing the plastic moulding for the seal to break thus causing the leak.

Mick

 

[guysy]

Cheers for the reply mate im glad someone has the other thermostat housing threads don't have many replys!

Yeah i thought id read that these engines are pretty good if maintained, im glad ive found the problem im going to get down to renault today and get the parts then fit them, with new housing thermostat and coolant...

One thing... when you bleed the coolant and top it back up... when you are bleeding the air out do you leave the coolant tank lid off? or just screwed on but not tight?

Then when you use the bleed nipple on the housing, do you just unscrew it till clean coolant is coming out with no air?

 

[guysy]

Well after all if was the thermostat housing, im updating this thread even though the problem is solved because a lot of problems get asked, but after the initial ask not many update the thread to say yes it was this and this is what fixed it...

So yes it was the housing... im not sure how but the inner wall of the housing was cracked so the gasket rubber ring was under pressure and with water flowing about made it flap about until it broke... so there was a cracked housing and split rubber gasket...

Once the coolant was drained and removed and then the old housing it was clear that this was the problem, so both me and my grandad where pleased it would be easy-ish to fix...

A new housing with a new thermostat inside cost £37... 5L of green coolant (although a chat with one of the renault mechanics telling me they now use blue stuff and green doesnt matter despite hearing type D green only) was £12...

Then the only other problem was the bloody gasket did not come with so i had to order and come back the next day for a gasket costing £3.50 for basically a thick rubber band!

All in all not bad... some gasket sealant was added on the face of it, bolted back on and new coolant and some air bleeding and back on the road... Happy days.

Pics, because they always help if you want to know what your dealing with:


Old and cracked

So if you have a leak under the air box on a 1.2 thats most likely your problem!!