Mk1 Coolant leak problem.

[getawayturtle]

Hello, the other night after a drive I noticed a lot of steam coming from under the bonnet. There was a loud hissing noise coming from the back of the engine, and by the looks of it the gearbox is absolutely covered in coolant. There doesn't appear to be anything leaking down the front of the block.

Unsurprisingly I reversed the car and found this on the floor:


I don't have my tools atm to have a proper look, as I would like to get the coil pack etc out of the way. I'm hoping it's just a hose that goes into the back of the engine? Just hoping someone on here might have previously had a problem coming from the same area.

Also, I'm worried, could this have blown my thermostat? Because I know the cambelt has to come off for that.

It literally couldn't have come at a worse time.

My car is a 95 mk1 1.8, Thanks for any replies.

[Oldandslow]

If it's at the back of the engine then it's probably the heater matrix hoses. Especially if there's a bit of an oil leak from the back of the head, CAS o ring, weakens the rubber.

[getawayturtle]

Thanks, I replaced the CAS a couple of months back trying to fix a running fault (it didn't work!) and the o-ring in the old one was toast. Never even crossed my mind to wipe the hoses off while I was fiddling around there.

[HaylingJag]

i had a leak from my heater hose going through the bulkhead, disconnected both and joined them with an elbow to prove the fact. Decided last winter it was too cold without the heater so connected them back up, put up with topping up the coolant, i thought. Low and behold no more leaks!!!!! been good as gold for the last eight months!!

D

[getawayturtle]

HaylingJag said:

i had a leak from my heater hose going through the bulkhead, disconnected both and joined them with an elbow to prove the fact. Decided last winter it was too cold without the heater so connected them back up, put up with topping up the coolant, i thought. Low and behold no more leaks!!!!! been good as gold for the last eight months!!

D

Interesting, does the coolant still flow to the heater if the heater is switched off? Just wondered if I would getaway with driving it until a replacement hose arrives.

I stuck my hand round the back of the engine earlier, the hose has gone all soft and can definitely feel the coolant leaking from it. At least it's a cheap fix!

[MX-5 Lazza]

The coolant always flows though the heater matrix, even when the thermostat is closed.

[pewe]

There's also a blanking cap almost directly under the CAS which is recommended for replacement on older engines. It runs horizontally in the opposite direction to the heater hose take-off at the back of the head. In the absence of an appropriate plug I used some small diameter silicone hose which I plugged with a stainless bolt covered in silicone gasket cement and nipped up with a hose clip.
HTH.
Cheers, Pewe.