Hi everybody.
I previously posted messages relating to the usual overheating problems on my Townie, and have gained a lot of useful info from the Archive.
I am still working through the number of possibilites, but have noticed a bit of a quirk in addition to the normal list of faults, associated with this problem.
My Townie runs o.k around town without any loss of water at all, the heater is mega hot, which might point to the fan being faulty or the radiator blocked.
My problem is that no matter how long I run the engine, there does not seem to be any pressure build up in the cooling system! I can safely remove the rad cap (new sort) whilst the engine is hot, without any loss or water.
Is this normal or does it point to something else.
Thanks
Steve
- (#9796) Steve Bowen, 2 Apr 04 15:19
I would suggest the fan coupling might not be as efficient as it should be, to prove it try locking up the coupling, some strong twine would be enough, take it for a run if it doesn't get so hot their is your answer.....get an electric jobbie.
- (#9796) Master_Simon, 2 Apr 04 23:19
If its not building up pressure either the radiator cap is faulty or there is a leak in the system. No pressure will cause the coolant to boil at normal running temperature.
- (#9796) dave Bright (Bournemouth), 3 Apr 04 00:06
If it gets hot but there's no pressure then there must be a leak.
After it's cooled right down is it still brim full under the rad cap? or do you have to top it up? (Sorry can't easily find your previous postings)
What do you observe in the expansion tank? Getting fuller or constant level?
- (#9796) Dave (Sussex), 3 Apr 04 01:16
steve,
by what you say i feel it all points to a new rad cap
it the cap that keep the system at 0.9 bar and you may have a fault on the cap or the wrong cap fitted,as a matter of servicing i replace my cap at every mot
- (#9796) dennis, 3 Apr 04 07:46
Thanks everybody for your replies.
I changed the Rad Cap and Thermostat for the new Toyota parts when I had the Townie in October.
I do not seem to be losing any water at all, and the expansion tank seems to be at the correct level before and after a run.
As mentioned, the heater gets mega hot.
I recently visited friends in Wales, up and down the mountains and had no problems at all on the outward journey. Before returning I checked the rad level and expansion tank and found that I had not lost any water, but on the return journey, the heater hardly got warm at all. But again once back home, I checked the levels and again found that I did not need to top up.
- (#9796) Steve Bowen, 4 Apr 04 15:03
Sorry but should have mentioned earlier that the overheating problems I referred to earlier appear to only happen on a motorway run of between 50-60 miles.
The two occasions that I have been on a motorway journey have resulted in a relay lift home.
On these two occasions, I have lost most of the water from the system.
- (#9796) Steve Bowen, 4 Apr 04 15:08
Overheating on motorways Sounds like a failing viscous coupling.
- (#9796) dave Bright (Bournemouth), 4 Apr 04 15:22
steve
i agree with dave that it sounds like the viscous failing,if it is then you might be well advised to think about a electric fan conversion i am about to convert my viscous to electric soon , i have been reading up on the job and collecting and buying materials to carry out work,got a twin ford fan unit from my local scrap yard £25,been buying fan control materials from demon tweeks motorsport direct
(www.demon-tweeks.co.uk)01978 664 466 give them a phone call and order catalogue i have found a posting i put up awhile back asking about elect/fan and i came across rob drinkwater website with helpful info on the conversion,you will need to do a little bit of homework before you tackle the conversion (meaning that you have a plan and all materials to complete job)
and you must understand the switching of the control circuit using 30amp relays and taking feed from live side of glow plugs,this way after you park up and switch off the fans can still operate to stop local boiling in the system.
once you do your homework and understand then the jobs not so scary.see below
dennis
dennis
tabrettdtec@aol.com
1/28/04 12:38 pm electric fan problems
has anyone who converted to elect fan/fans,did you have any problems installing system and once installed
how well did it stand up against the viscose fan.
any information will be very helpful.
dennis
rob drinkwater
robdrinkwater@hotmail.com
1/28/04 3:53 pm electric fan problems
take a look at my webpage to see my conversion. carried out two years ago, with perfect results. better mpg, more usable power & more stable temperature.
http://www.robdrinkwater.pwp.blueyonder.co.uk/rjd%20computers/towniepics.htm
dennis
tabrettdtec@aol.com
1/30/04 11:14 am elect/fans
many thanks rob,
i found your web site on electric fan conversion most hslpful and now i am prepared to face the job in hand
i will post how i get on.
- (#9796) dennis, 6 Apr 04 11:18
If you're only overheating on the motorway (implies long periods under load), I'd beg to differ on the VC, unless that is, you're holding 80+mph the whole time. The coolant has to be going somewhere, first clean the sealing face in the filler neck, then have the system pressure tested hot AND cold. A good cooling system should hold 0.9bar infinitely, and withstand boiling until 115-118c by which stage even the standard gauge will be heading for the sky...
What model is yours A 4x4 auto's electric fans should be on at that stage.
Bottom line is, whether it's the VC or a pressure leak, by now the result is likely to be the same- a dodgy head/ gasket seal. It's a viscious circle. Even a small water loss will lower system pressure and therefore boiling point, increasing loss.
- (#9796) David Miller, 7 Apr 04 01:10