Hi guys

I've changed the thermostat/ red coolant on my focus MK2 couple weeks back and last Sunday night driving it my rad hose burst from engine to rad upper hose and had be put on truck home, that cost me 50 quid for new hose. 2 lots of coolants 40 quids worth in 2 weeks.  I also replaced the cap as well 

Now I'm not getting any pressure when cap taken off you usually get a little bit pressure.

Driving it last night also I saw my dash stalk digital trick thing go up to engine temp 144 and the gauge temp gauge was halfway and fan was going crazy and continuing after I stopped for about minute.  I know I think u have to take 40 off that's still 104.

Please guys need help .

Thanks

Maximum possible temperature for the coolant is 100^oC unless of course it is kept under pressure. However you say there is no pressure in the system 🤔 This defies Boyle's law and would make your car of interest to the scientific community 😀

You most likely have an air lock in the system. Take the cap off the coolant tank (when cold) and start the engine, let it idle up to normal operating temp, and the air will probably find its way out.

Glycol also increases the boiling point.  Not as much as pressure, but 105c is a reasonable amount for a water/coolant mix.

Bursting a rad hose takes some doing though.  I wouldn't expect that to come from just an air lock.  Perhaps it was already weak and then got bent around while doing the stat?  Or perhaps a clamp was left rubbing against it?  Last time I burst a rad hose it was caused by a blown headgasket.  

Last Sunday

I've also brought coolant sensor why not that cheap. Not put of on yet

3 minutes ago, madman said:

Last Sunday

Did you have to disconnect that one to do the stat?

Thanks you saying about head gasket that's what they thought few years back when my coolant was chocolate milkshake, which was oil cooler in the end

Rad hose was left on didn't touch it. That stat was done couple weeks back battery disconnected, alternator out, steering fluid bottle moved to side, drained coolant from drain off cap. The coolant when hose exploded has covered the whole engine. 

As my car is freezing cold now. Are the coolant sensors hard to do.

I would be concerned about why it blew if you never touched it or anything near it.  Seems too much of a coincidence to just fail from age now.

Coolant sensor should be easy, just take care not to damage the housing.

How the hell u ment to remove the nut.

With a spanner.  You can also use mole grips or waterpump pliers to loosen it, then undo the rest with your fingers.  Looks like it's been leaking before as someone's added PTFE tape already.

How do u tighten it up again no space. 

Tried a spanner no room to turn it. Tried a socket set and drop socket in engine. 

I've not put tape on it.  I've got mole grips and water basin pliers.

 

Just do whatever you have to with the tools you've got.  Or take it to a garage and they'll do it in 30 seconds using a short or bendy spanner.

4 hours ago, madman said:

How the hell u meant to remove the nut.

 

the hose looks worn out - that's what the bulge tells you - wouldn't stress over that

 

how is that easy to reach sensor difficult to reach ? - try the right rear exhaust manifold gasket on a XJS V12 so you can swap out the starter motor

as for the hose spring clips - buy a silly tool that allows you to release without fighting your hands in a small space - most places do them these days

https://www.ebay.co.uk/itm/202812374257?

Had to remove the coil pack above it to access the coolant sensor, still never did it tho. A spanner had no space to turn it and socket wasn't long enough to go over the sensor to reach the nut. 

Coming back home tonight dash stalk trick showing engine temp 145c. Temp gauge halfway and fan going crazy. I've not heard fan in last year as stat been stuck open..

Is this right this engine temp 145c. The  Stat description I brought says operating temperature 98c.

Thanks guys

98c is the correct stat for these.  They are designed to run hot for maximum efficiency.  The fan shouldn't be on all the time though, something is wrong here.  Either there is still air in the system, or the waterpump isn't circulating.  Is the top rad hose hot?  Are the cabin heaters hot?

Hi guys.

Top right when yeah gets hot that's the new one that burst and heater gets red hot can't hold hand over it.

I noticed the temp gauge is moving between first mark 75c and just under second mark 90c. 

Is there a thermostat test you can do, you can't really take it out and plonk it in water. 

Where is the water pump on mk2 ti vct engine, I've noticed couple drips on the under tray underneath all the pulleys, that could be from when hose burst as did lose lot of coolant everywhere. 

Thanks guys

Can't really test this type of stat unfortunately.  But if the top tad hose is hot then the stat must be opening.

The waterpump is driven by the aux belt.  It's the smooth black pulley right in the middle of all the pulleys with 4 bolts through it.

Yeah the upper right hose gets hot very hot, but it if stat was stuck open it still get warm to hot tho.  When a engine is warming up until the stat opens at 98c does the upper rad hose still get warm to hot.

I've noticed bit water on the under tray below all the pulleys would that be pump only or could stat/tank/cap or maybe water left over from the hose Xplosion.

Cheers guys

there are two design of thermostat

 

the cheap simple one

the crazy electrically heated stat - obviously the cars that got this "improvement" have an electrical connection - when the PCM decides it should - it turns on the heater to get it to open quick - when her stat heater circuit died (comes up in diagnostics) it sets the fan to run virtually all the time

11 hours ago, madman said:

Yeah the upper right hose gets hot very hot, but it if stat was stuck open it still get warm to hot tho.  When a engine is warming up until the stat opens at 98c does the upper rad hose still get warm to hot.

I've noticed bit water on the under tray below all the pulleys would that be pump only or could stat/tank/cap or maybe water left over from the hose Xplosion.

Cheers guys

Water can't flow through the radiator until the stat opens.  So on most cars the top hose will stay cold until the stat opens.  Although with this engine having the stat at the other end of the radiator, there could be some heat transfer into the top hose while the stat is still closed.  If you can reach the radiator, that might be a better indicator of whether the stat is open or closed.

Water on the undertray could be from any of those things.  Best thing to do it dry it up and see if it comes back next time you run the engine.

Stat is on middle left near the pulleys and another valve is on top right just behind headlight. 

I know it's coolant on under tray I dabbed it with kitchen roll and it was pink.

U got the under tray from left to right the whole of the lower front car.  This coolant is on little piece of under tray attached to main undertray under approximately air conditioning pump. 

I found water pump 4 bolts on is that a case of timing belt off and cover and expensive job. As before when I had timing belt done he said it was attached to timing belt and only the timing belt was done as water pump was fine. 

Thanks guys

25 minutes ago, madman said:

Stat is on middle left near the pulleys and another valve is on top right just behind headlight. 

I know it's coolant on under tray I dabbed it with kitchen roll and it was pink.

U got the under tray from left to right the whole of the lower front car.  This coolant is on little piece of under tray attached to main undertray under approximately air conditioning pump. 

I found water pump 4 bolts on is that a case of timing belt off and cover and expensive job. As before when I had timing belt done he said it was attached to timing belt and only the timing belt was done as water pump was fine. 

Thanks guys

Yes there's an electronic stat at the top but that just controls the flow back to the reservoir.  (Known as degas)

The actual stat that you replaced controls flow from the bottom of the radiator, instead of the top, so it's backwards compared to most engines.

We really can't guess where the leak is from just by seeing it pool on the tray unfortunately.  You would need to find where it's coming out higher up.

The timing belt does need to be removed to replace the waterpump on these, although the waterpump is not driven by the timing belt.  It's a terrible design tbh.

Had car running for over half hour. The upper right hose cold then at 98c red hot.

When it's below 98 nothing no drips. Thermostat opens at 98 and I can see the expansion tank leaking. The tank looks more full when stat opens up, I took cap off after hour and no air release.

 

Sounds like it needs a new tank then.  Will be cracked somewhere.