Temp Gauge Again

[David Edwards]

Right peeps having literally just got in from a week at Dawlish Warren, back to the problem I thought I had cured, lol. Brief reminder: On normal short journeys the needle stays at the 11 o clock. as it always has done, same on motorway runs if I stick to around 60, however if loaded up or going up a gradual long incline, the gauge creeps up to just below the end..put the heater on full blast and down it comes immediately to the "normal" 11 oclock.
Now I have changed the thermostat and had the system flushed which I thought had cured the problem but it obviously has not,lol. Also, although it may not be related, even after a long journey like today from Dawlish Warren to the welcome services before Bristol where we stopped for coffee, upon starting her up..which she does first time no probs...black smoke not white like she was a 1000 year old oil burner. I have checked for leaks and there are none, now apart from ripping the head off to see if there is a leak I am at a loss, she has been pressure tested and all is well, she does use some coolant but where it goes I do not know, there is no milky stuff in the header tank and all seems normal although it does drop. Any help will be very much appreciated, this is driving me mad now.

[missfixit70]

Have you checked the pressure cap on the header/expansion tank, could be leaking.
Did you fit a Mazda original stat, if not that could be your issue, a few people recently have cured problems by fitting a Mazda stat, do a search. They may open at the same time but at the top end it has to seal against the inlet into the thermostat housing from the engine recirc, if it doesn't do that you'll run too hot as it won't force the coolant flow through the rad. I seem to type this every other day
If your gauge is not modified, it is running very hot & you will cook your engine if you continue to drive it without sorting it - if you haven't already.
Get the coolant checked for exhaust gases, try a pressure test with the engine hot & have aread through all the recent threads on cooling/overheating/head/pinhole leaks/porous hoses type issues.

[haydn callow]

The thing is Dave...you can be driving along with the gauge sitting at 11 o'clock all happy and content....what you don't know is what temp you are running...11 o'clock can be anywhere between 60C & 110C you could (in a very fit Bongo) be running at 88C, but I suspect in your case you are running at 100+C, not good at all and once the gauge starts to move you are in deep dodo.
This is why I personally think it is a good idea to do the gauge mod (which costs nothing) this will give your gauge some real meaning.
11 o'clock can be good or bad....how do you know..

[Northern Bongolow]

do a preasure test to find any leaks,but also sounds like a non mazda stat/port face dirty,not shutting off the head flow completely, so you are on an ever increasing temperature curve when working the motor hard until you reach the cap preasure blow off point.
sounds like the system is near the top end limits.are the fans on when the inrease is noted.

[DE-OGZ]

Hi Peeps

Doin my guage mod tomorrow, reading the fact sheet I may want to put fit 110 ohm resistor so normal running shows as fairly vertical just a psycological thing really (I'll try the 100 ohm first tho)

My quick question is "two 1 watt 110 ohm resistors in parallel" does that mean the legs of both resistors in a spade connector to
'T-U 'and the other two legs in a spade connector to 'E'

oh also is there a right and wrong direction for the resistors (direction of flow kinda thing)

Cheers - J

[g8dhe]

Ah, two 110Ω in parallel will give you 55Ω.
I don't think you will find that the wattage rating is critical, it was used to ensure that the leg wire was stiff enough, I went in the other direction and used a very low wattage resistor so there was less mass to support. Its been in place a month now and no problems. Just use a single 110Ω resistor will be fine, going by my experience.

Oh and no resistors are not directional, unless you want to read the colour codes in opposite directions

[DE-OGZ]

Thanks for the quick reply, off to maplin in the morning

[g8dhe]

Just thought did you mean two 220Ω resistors rather than two 110Ω in which case yes that will give you 110Ω?
But again that's making life difficult, just use a standard 100Ω resistor its easier to fit.

[DE-OGZ]

yup i think i did mean 2 x 220 but happy to go with the advice that 1 x 110 will be ok

PS love your web site the pics of lulworth cove are gr8, I do a fair bit kayaking there and abouts.

[David Edwards]

Thanks peeps will try the cap and mod too, if that dont work well..might just get shot of it and get something else, after all its only a car.
Asking a daft question..again,lol, (forgive me but I am in tremendous pain with my shoulder) which fact sheet is it, I take it there is a link somewhere.

[casrockbongo]

Just want to echo what Kirsty has said above about the genuine stat. We had 2 blueprint stats in 2 months and had it all bled up etc. ..etc .. pressure tested, no loss of coolant and so on... BUT our temp gauge would go up when going at speeds on the motorway, or up an gradual incline as you describe. Fitted a genuine stat and gauge sits 'happily' at 11 o clock . .

Although note Haydn's view, as I am not convinced that my engine is not still running too hot . . just not over 110 degrees . . .and inevitably the engine is going to go all wrong (techie term) if it is running too hot for too long . .

[David Edwards]

There seem to be a few different temp variations with the stats, I know one of the stats for my bongo is code j533015, is there a particular one for mine, a 96 on a P plate, wl code, in relation to the temperature some are quoted at 83 degrees some higher.

[Northern Bongolow]

i stand to be corrected but i've only seen one stat for the whole range,but not had a lot to do with the petrol's.

[missfixit70]

With the problems you're having David it'd be daft IMO to fit anything other than a genuine Mazda stat, only one for the diesel AFAIK, I don't think that's a Mazda code is it?
I see you got that off the compatible list as written by Maxheadroom who has now fitted a genuine Mazda stat due to the compatible stat not doing the job properly ( new head now fitted)

[missfixit70]

Thanks peeps will try the cap and mod too, if that dont work well..might just get shot of it and get something else, after all its only a car.
Asking a daft question..again,lol, (forgive me but I am in tremendous pain with my shoulder) which fact sheet is it, I take it there is a link somewhere.

Gauge mod here - http://www.enginesaver.com.au/Tempgauge.pdf or simply fit a Mason alarm which does the same thing & also provides a settable audible alarm & is only 3 wires to connect at the back of the gauges - http://www.townace.plus.com/ie/ietemga2.htm