T25 Overheating

[ghost123uk]

What is the consequence of running without a thermostat for a few days?

Won't do any harm for a day or 3, just won't get as hot as it should !

p.s. = Don't forget what Martin said a few posts back, test it all out, bleeding, driving a day or 3 without any antifreeze in (as long as we don't get a sudden cold spell !). Then when happy all is OK, drain again and put the required 50/50 mix in it.

p.s.s. It would do no harm to undo any hoses that are low down in the system when draining it, just to make sure you get all the old coolant out. I do drain the rad by taking the hose off at the front (a bit tricky) but many don't.

[kevtherev]

Radiator Bleed screw is on the top of the later rads.

it''s on top of all the radiators I should say

[Oldiebut goodie]

It would take a genius to get air out of the bottom of a radiator full of water and air. Maybe the laws of physics have changed recently!

[kevtherev]

perhaps the poster is confused by the coolant flow picture..
The rad on a T25 gets warm at the bottom first..

[Nitmoi]

The picture of the radiator parts is rotated through 90 degs. That was why I mentioned it.

I understand older rads had the sensors in the wrong place at the top. I imagine the bleed screw was at the top on older ones (makes sense) but I never saw one.

I took out the thermostat today and it appears to be running well and runs a bit slower which is a plus.

The old one behaves well in a saucepan but might have been jamming in situ. There was a load of old sealant inside the cover holding the stat in place too!

[isaune]

OK - I'm all set to start the drain and refill operation in the morning.

Bit nervous but hey?

Two little questions:-

I am assuming I need to be lying on the ground under the van at the back to release the hoses - is that right? In which case, do you think it will need jacking up? That's not a problem - just a bit scary.

Secondly, the clips on the hoses look like nothing I've ever seen before. Is there a knack to getting them off? Looks to me like you squeeze the 2 ends together with pliers and they open. Is that right?

And putting them back is a case of holding them open until in position then letting go?

Finally, when it comes to flushing through with plenty of water - where do I stick my hose - oo er missus!!

In the Header tank maybe?

Sorry with all the questions - just want to get it right.

Thanks again for advice.

Ian

[kevtherev]

I can see my hoses from the bottom grill
Use a set of mole grips to compress the sprung clips and ease them off the stub

[isaune]

Ahhh. You're talking about the hose at the front, Kev.

I was going to drain it from one of the hoses near the engine down under the van.

Sounds much easier doing it from the front grill.

Thanks a lot.

Ian

[ghost123uk]

Those clips are a serious pain in the butt (unless you have the special tool).

Mole wrenches, pipe wrenches, hacksaw

Replace them with jubilee clips (or buy the special tool )

[Ian Hulley]

Those clips are a serious pain in the butt (unless you have the special tool).

Aka 'Tw@t clips'

(unless you have the special tool).

I use waterpump pliers, most are fine depending where they are on the engine BUT if some numpty has let them spring into the wrong place it's trouble o'clock.

Ian

[isaune]

Hi everyone

Sorry to resurrect this old post.

Anyway, a quick update is that I eventually had the system drained and refilled by a mechanic and, although he said he didn't think the refill took the recommended 16 or 17 litres, at least the 50/50 mix was right and, by and large, the van has been trouble free for the past few months.

My reason for writing now is just a little niggle which is playing on my mind.

About every few hundred miles or do, the red temp light starts flashing and a little top up of fluid (maybe half a pint) makes it ok again.

Well, we are now about 400 miles into our 6 day French road trip (see "100 miles from Calais" post on camping forum if interested) and the van has been impeccably behaved until a few mins ago when the red light started flashing. This was after around 70 miles at about 70mph.

Ok, I know my next step is to let it cool down and top up both the tank behind the number plate and the one by the engine but I have just checked behind the number plate and that tank is virtually full?

Is that normal?

Also, the fluid in that tank is cold?

Is that normal?

TBH I can live with a half pint top up every few hundred miles but, as I say, I just have this little niggle that something is not quite right.

Any ideas please?

Thanks

Ian

[frenchwesty]

Seems similair problem I have just had also. We have a 1.6D CS engine and we live in France, just got back from a 70 mile trip camping for the weekend. parked van up all was fine even on motorway no probs at all entire journey. After uloading took her to village car parks down a steep hill and all of a sudden temp guage shot from halfway to maximum and red light flashing but no fan coming ON as it normally does if she gets hot. Turned engine off and rolled to a stop, checked coolant tanks the one under number plate full, the one by engine was just under minimum so filled her up, started her again and seems to run fine no flashing red lights or running hot at all, hope all is OK!!!

sounds just like your problem maybe a samll leak somewhere possibly or worse??

Good luck

[isaune]

Thanks Frenchwesty.

Yes. I do think I must have very small leak somewhere but damned if I can find it.

However, unlike yours, I think my flashing light means low coolant level as opposed to temp too hot.

And I am happy to say my fan clicks on and off like normal.

I am just confused that the tank behind the number plate seems always to be cold, even at the end of a long journey????

[kevtherev]

it's cold because it's just an expansion chamber... there's no flow through it

[isaune]

But what's the point on an expansion chamber if the hot water doesn't "expand" into it when hot?

And if the main system is a little low, why doesn't it draw coolant from this tank?