Its me again!!!!
I wont bore you all with my story of my townie, surfice to say I've got it back but the mech cant gaurantee it wont go BANG!
Sooooo gotta sell it, BUT why does the temp guage go up and down when driving??
It goes up to overheat...then drops down to normal, all I'm doing is driving in a staright line, no pressure on engine, so WHY?
Take the other nite temp guage going up & down but THEN goes right into red (& beyond) got home gently took of rad cap and sooooo much air comes out, fills it up drive of and STILL the temp guage goes up (& down
I'm a plumber (by trade) it seems to em as if the whole bloody coolant system is filled with AIR!!!!

I know how to get it out of central htg BUT how do i get it out of my townie????

thnaks Guys (&Girls)
- (#11736) Jeffers (yes me again), 24 Jun 04 15:31

souds like you might have a sticky thermostat. Have you changed it recently, and if you did, was it a toyota 30mm one or a 25mm aftermarket? the after market stats can jam in the receiving plate right behind the thermostat.

If you remove the radiator cap with a hot engine, normally arround 100 C but will be higher if its near the red mark, then you will lose pressure and the coolant will boil. This can look like air, but is more likely to be steam pressure.

- (#11736) dave Bright (Bournemouth), 24 Jun 04 16:31

Same principle as plumbing....vents from highest point.
I drilled out an old rad cap...added a gasket or 2 , and some hermetite....bit of tube..into an upside down bottle (bottom cut out)......fill the bottle half way, extending the head. Massage the hoses etc. (when cold).
Make sure you have the right townie rad cap with the negative vacuum float + ensure its sealing well....checking through to the pick up tube in the expansion tank.
Personally, I think its a shame toyota didn't fit those little bleeder valves in strategic hoses, like peugot/renault etc....

- (#11736) chris turner, 24 Jun 04 16:56

Well, the gauge shooting off into the red and back down again is a good indicator for no coolant...

So, as Chris says, check for tiny (impossibly small) leaks, as it's likely that your system is unable to draw a vacuum, and thats recuperate as it cools down. This'll empty the system over a period of time.

But there's no black magic to filling and bleeding. Ensure front heater is set to hot, fill (at filler neck), start engine, top up as necessary for the first few minutes. Then put on the rad cap, go for a drive, then let the system go stone cold. You can then remove the rad cap, and coolant should be visible in the filler neck.

If not, you've a leak. If it blows coolant out at idle when cold, you've a h/g problem. Plenty of info in the archives on both subjects...

- (#11736) david miller, 24 Jun 04 22:24

my liteace had the same problem turned out my rad was almost fully blocked so it was not releasing enough cold water back into the system when the stat opened
hope this helps
regards keith

- (#11736) keith wright, 26 Jun 04 08:54

i had similar problem with always having air in system. found a tiny hole in rad. when system under pressure and hot it was blowing out, when cooling, instead of drawing water in from expansion bottle, it was drawing air in from hole, so checking level in bottle always appeared correct.

- (#11736) eddie arrowsmith, 27 Jun 04 15:28

I had exactly the same problem. It would jump up and down, then go right off the scale and stay off the red line even on starting up.

It did not seem to be overheating. There appeared to be plently of coolamt. But it scared me.

I took advice from this board and replaced the radiator cap with the new recommended one on Ace Answers (about £12) from a Toyota dealer.

It solved the problem completely. Now the temp gauge is solidly at about 11 o'clock.

Good luck

- (#11736) Malcolm Stroud, 28 Jun 04 08:14