Dear All,Just fitted a Dave Mason temp.gauge mod.and apart from frightening myself to death,have had the following results.Any suggestions welcome.
Gauge is 20 dot type.
Light running on level 18/19 dots,by accident found that if in 2nd.gear on flat temp.goes down to 15/16 dots.
Slight hill----in the red to max.
Down hill second gear braking cools to mid guage/slightly over.
No sign of head gasket failure,cooling fluid looks ok,no oil or other nasties in it,or in the oil.
Before fitment gauge would run just under to just over mid point.Just cruising around avoiding any nasty hills at the moment,very frustrating.
To add to my story if engine switched of at just below the red,I can come back 10/15 mins later and the engine has cooled to 12 dots,seems a lot to cool down in such a short time.
Want to lock my fan up to see if this runs engine any cooler,can anyone tell me how to do this without causing any damage to it.
Any clues to my prob.guys.Peter

- (#11457) Peter Tucker., 31 Oct 03 5:38

Is this the bridging resistor or the temp alarm?
In either case I would suggest that you have the wrong resistor for your setup, does removing it put all back to normal?
Don,t lock the fan up!

- (#11458) Clive, 31 Oct 03 6:05

Pete, as Clive says locking the fan up might seem a good idea, however you will encounter some unwanted side effects like -
A condensation problem inside the engine , this is due to the engine running too cool to rid itself of the enevitable moisture build up.
Less MPG,s (engines are designed to run at certain temps, thats why we pressurise the rad to cheat the boil limit to well over 110 degrees
A confused post heat cycle from ecu to the heater plugs
lastly , you will knock quite a few bhp,s off by driving the massive fan directly
regards jim

- (#11459) J Adgo, 31 Oct 03 11:06

Clive, Peter has the full modification, not just the bridging resistor.
Of the 30 or so customers who've reported back to me this is an exceptional result - much more movement of the pointer. My first reaction was that the modification is wrong, in which case I'll happily try to rectify that, but I thought maybe the cooling system IS struggling. Note the gauge is just OVER the mid-point without the modification.
I recommended trying to lock the fan coupling purely as a temporary test to see if the coupling has failed. I've read of owners doing that but couldn't tell Peter how. After that I wonder if it may be the thermostat stuck almost closed, or even just an airlock.

- (#11460) Dave Mason (Sussex), 1 Nov 03 1:13

Hi Guys,What a wonderful site,and how confident you can get with all this info and input.Thanks for all your comments,but one thing I have learnt since fitting this mod is where the townie is ok and where it struggles regarding the temp.of the engine.Although I have no signs of trouble as coolant looks good,no major loses,and no nasties in the oil,Iam of the opinion that my system is starting to struggle,maybe coincidence that I fitted the mod.just in time.After finding this site I bought a new rad cap[toyota with plastic float]so that should be no prob.I am going to get the system flushed and new thermostat,and will report back.meantime I am cruising around and adapting my driving to the alarm so should be safe until then.Any other thoughts will still be apprreciated.Peter

- (#11461) Peter Tucker, 1 Nov 03 12:05

The only variable worth talking about is the sender. It might be worth doing a cold and hot resistance check (even better if it's removed and tested in a pan of water...), as if the engine seems OK there might not be a prob as such. Dave, you've got the R/T graph from the manual, no?

- (#11462) david miller, 1 Nov 03 13:46

Peter,
As normal I jumped in without reading and digesting...
Spoke to Dave Mason yesterday at the Day jam, we are of the opinion that you may have a problem that the guage mod has highlighted.
If you are in/near Bristol I'm happy to take a look.
Clive

- (#11463) Clive Bristol, 2 Nov 03 1:24

Hi Peter
Don’t Like to but in here, but as Clive says, we discussed this at the Day jam, and it sounds suspiciously like the thermostat.

Earlier this year I decided to do some work on my cooling system, and ended up fitting an aftermarket thermostat. My temperature gauge started to behave in much the same way as you describe, over heating and over cooling. The aftermarket thermostat was only 25mm in diameter, not 30mm like the original one, so the flow of coolant was severely restricted. I also discovered that it had a larger C Clip on the engine end, and that was catching on the receiver plate mounted inside the engine block. That caused the thermostat to stick as it opened and closed, because the clip had to be forced through the hole, thus slowing the opening and closing time. If your existing thermostat is on its way out, it might well be sticking, so replacing it would be a good idea. Do make sure it is the proper size, and get a new O-ring seal. They are separate parts, and don‘t come together.

If you are going to flush the system consider a descale as well. I read somewhere that if you ask Toyota to flush the system, they don’t descale it, so if your local Toyota dealer is doing the work, you will have to specifically ask them to do a descale.
Good luck
Dave Bright

- (#11464) dave Bright, 2 Nov 03 11:34

So has the sender been confirmed 100%?

- (#11465) david miller, 2 Nov 03 13:11

I've had my alarm fitted for a couple of weeks now and one thing i have noticed is that the temp gauge does now indicate when the thermostat is opening so giving me much peace of mind while drivingexcept on hills where i get very paranoid when the pointer almost touches red but i seems i'm not the only one with this result

- (#11466) brian squire, 3 Nov 03 0:01

Brian,
After a while you tend not to be fixed on the temp guage as much. I still look but depend on the audio alarm for getting my attention.
It's my opinion that the AceAlarm is the best thing you could get for your Townace.
It has highlighted above that there could be a problem, that the normal gauge only suggested, and could have been read as normal!
See Ace Answers for details on how to get yours, simple to fit, easy to use and worth every penny in my book.

- (#11467) Clive (Bristol), 3 Nov 03 2:02

David Miller
I suggested testing the sensor output early on, direct to Peter. He's not equipped to do that.

- (#11468) Dave Mason (Sussex), 3 Nov 03 5:58

Another thing worth adding here is that there's some missing information as well.
In one of our talks at the day jam, it emerged that the normal unmodified gauge was indicating noticeably above and below, the usual static central position on the gauge before fitting the alarm. Hence suspecting the thermostat. Hope that helps
dave Bright

- (#11528) dave Bright, 3 Nov 03 6:17

OK then, I'll just go back to lurk mode on this one...

- (#11529) david miller, 3 Nov 03 8:17

Yes, Peter, a lot hangs on your statement in your very first posting, "Before fitment gauge would run just under to just over mid point." - I've assumed that means "Before fitting the modification". I think this is what DaveB is referring to, two postings up, as "missing" information. Correct us if we're wrong. It's unusual for the unmodified gauge to move at all once the engine has warmed up.

- (#11530) Dave Mason (Sussex), 3 Nov 03 9:54

Dave.Yes,before I fitted your mod my gauge would read slightly under to slightly over the mid point.Before finding this marvallous siteI always thought how constant the engine temp.was and assumed this was good,no wonder so many people get caught out,as I now realise the large amount of temp.variations there actually are.I reiterate that i shall not panic and assume I have a major problem until I have the cooling system overhauled.Meantime I am adapting my driving to the alarm and she is quite happily cruising around.Many thanks to all those who have discussed and commented on this problem,the mod is the best thing since sliced bread for the townie everyone should have one.Whilstwriting I would like Clive totake a look for me.I am in bristol and will contact in the next or so to arrange a convenient time.Again many thanks to you all.Peter.

- (#11531) Peter Tucker., 3 Nov 03 14:03