Td5

[Guest Nik]

Gents sorry to keep going on about this bloody car but I have a couple of things I still don't understand. 1. If the water is not circulating for whatever reason why is the car not getting hot? 2. If it is the water pump impella why does the water flow faster when revved up? I know I should bite the bullet ang pull the head off and get it sorted but just want to explore every avenue and fully understand I have done all I can to eliminate anything else. As always any advice it much appreciated. Nik

[Guest 2b cruising]

It sounds to me that you have got circulation.

What faults did you have on road tests after doing the t/stat?

[Guest Nik]

The bottom of the rad is stone cold. Little bit of pressure in the expansion tank but really was next to nothing.

[Guest 2b cruising]

Was this after a run out?

[Guest Nik]

Yes done 5 or6 miles

[Guest Nik]

If it wasn't for rad being cold I wouldn't say there is anything wrong with it

[Guest 2b cruising]

If the pressure was not enough to start pumping coolant out of the header tank, try using it on longer runs.

If it gets very hot at the top hose but not the bottom, it's defo circulation for some reason.

Try running without t/stat in if possible.

[Guest 2b cruising]

If it still runs cold bottom end after this, flush rad out.

Some rads have very fine tubing for the core that can easily get blocked.

Especially if someone in the past has used a rad sealer for a leak. Or even had rad block cos some idiot put oil in one to get at their boss.

[Guest Nik]

Took it on a longish run to a hilly area gave it a bit of stick going up hills temp gauge at half way as normal, don't get hot don't lose water heater fine. May look at flushing rad through.

[IanS]

Rad hot at top and cold at bottom is rad and thermostat working.

Thermostat controls flow to keep engine hot, so with coolish air temps the water getting to the bottom of the rad will be cool to cold.

at lower power the thermostat will be almost closed and restrict water flow through the rad so that by the water gets to the bottom it is cold.

Dont forget that the rad will be sized to still work in death valley at the hottest day of the year whilst towing a couple of tonne trailer up a 1 in 4 hill.

[Guest 2b cruising]

He has already renewed the stat. I've asked him to do a shortish journey with stat out. If same then, go for rad blockage.

[Guest Nik]

After taking it on a decent run all seems ok. Temp good and water seems to be flowing ok and rad is warm. Dilemma now is how do I get antifreeze in it without filling up with air again!!

[Guest Nik]

And thank you all for advice over the last couple of weeks

[Guest 2b cruising]

You must put antifreeze in Nik.

It does more than stop it from freezing.

It also stops sludging and corrosion, especially on aluminium or cast.

It's also getting quite cold now anyway.

Try a cheeky one and do half litre at a time if you have a dedicated radiator drain plug.

Leave rad cap off when draining.

Ensure you get in as much as you drain each time.

When it's coming out of the drain looking like it's neat antifreeze, run the engine till it mixes.

50'/, is a good mix but don't struggle to much to get this as anything is better than nothing.

The freeze point of -18 at 50'/, is correct as that factors in for the wind chill factor when travelling at speed.

HTH. Ken.

Edited October 12, 2015 by 2b cruising