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Just a thought
Posted: Wed Mar 10, 2010 11:36 am
by haydn callow
For those of us that have the winter pack exaust recirculating valve still in position... Would shutting this valve help in getting the engine up to temp when bleeding (i.e. get the stat open quicker)
Logic says it could be a big help
Re: Just a thought
Posted: Wed Mar 10, 2010 2:22 pm
by missfixit70
Yup I reckon so, it's there to get things warm quicker, BUT, bear in mind the risks of them sticking shut as has happened to several peeps before. looks like you should be able to open it back up manually though if it does get stuck?
Re: Just a thought
Posted: Wed Mar 10, 2010 2:40 pm
by mikeonb4c
Is it really worth the bother esp given the issues with them sticking? 3 mins of tickover plus 5 at 2500rpm was enough to get my stat open when I did a coolant change on a cold Monday
Re: Just a thought
Posted: Wed Mar 10, 2010 2:50 pm
by missfixit70
Be an interesting comparison to see if it did make any difference in getting it up to temp.
Getting the stat to open isn't too much of an issue, you've got to continue on & get it to open FULLY, so it shuts off the top recirc & opens up the bottom hose flow fully to ensure it's bled properly, unless you get to that point, the rad won't get full flow & the bottom hose will not get hot, if you don't get to that point you haven't proved the stat is working properly & all parts of the system bled properly. You may be lucky & it will bleed ok by just opening the stat, but personally I'd want to know that the system is able to do what it's supposed to when it's put under heavy load
Re: Just a thought
Posted: Wed Mar 10, 2010 3:07 pm
by haydn callow
Mike..it isn't a bother...just a switch to "flick" it is only a thought and I do not recall seeing this mentioned before. I cannot get a stat open in 8 mins from cold and I have done a lot of different Bongos...I would say 30 mins was pretty good
Re: Just a thought
Posted: Wed Mar 10, 2010 10:29 pm
by mikeonb4c
haydn callow wrote:I cannot get a stat open in 8 mins from cold and I have done a lot of different Bongos...I would say 30 mins was pretty good
Apologies Haydn - getting my stages mixed up. 10 mins at tickover and 6 mins at 2500rpm as per workshop manual worked fine for me and Ronhud when we did both our Bongos on Monday. 30 mins sounds surprisingly long but you're the guvnor so I'm not going to argue. I don't worry about bottom hose getting hot though, just as long as its warming so I know coolant is flowing round the system. Maybe that explains the difference. Bottom line is it takes however long it takes as the job can't start until the bottom hose is warm (the workshop manual recognises that by saying to go for another 3 mins at 2500 if the hose hasn't started to warm). I wonder how many Bongos may have sluggish stats
Regarding the switch flicking, as Kirsty has said it is the stories of things sticking that makes us flag up caution. Otherwise I imagine it is simple enough.
Re: Just a thought
Posted: Wed Mar 10, 2010 10:37 pm
by missfixit70
So if you didn't get the bottom hose hot, how do you know the stat is working properly over it's full range & it's bled properly? As I said above if you don't get it hot the stat hasn't opened fully forcing all the flow through the rad.
Re: Just a thought
Posted: Wed Mar 10, 2010 10:50 pm
by mikeonb4c
missfixit70 wrote:So if you didn't get the bottom hose hot, how do you know the stat is working properly over it's full range & it's bled properly? As I said above if you don't get it hot the stat hasn't opened fully forcing all the flow through the rad.
The workshop manual says it needs to be warm. By the time you've continued with the sequence in the instructions, it's hot. Its how I did it last time and had nae bother so I guess the workshop manual is giving sound advice. I guess the sequence in the instructions are laid out so you can do the job safely without running and gunning the engine more than necessary.
Re: Just a thought
Posted: Wed Mar 10, 2010 11:31 pm
by missfixit70
So you did get it hot then, that's ok.
Re: Just a thought
Posted: Thu Mar 11, 2010 12:17 am
by mikeonb4c
missfixit70 wrote:So you did get it hot then, that's ok.
Indeed I did
And in rather less than 30 mins
Maybe me and Ronhud just have very healthy stats
Or maybe we're about to wreck our Bongos
Re: Just a thought
Posted: Thu Mar 11, 2010 2:12 am
by missfixit70
mikeonb4c wrote:missfixit70 wrote:So you did get it hot then, that's ok.
Indeed I did
And in rather less than 30 mins
Maybe me and Ronhud just have very healthy stats
Or maybe we're about to wreck our Bongos
Not being pedantic or owt
but I just looked through the "official" workshop manual bleed procedure in the fact sheet, if you follow it as it says, the minimum it should take is @48 minutes up to @60 minutes.
Broken down - 10 minute idle, 6 minute revs (extra 3 if bottom hose cold), 4-5 x 8 minute cycles of revving & idling.
30 minutes suggests it hasn't been bled proper from that.
Re: Just a thought
Posted: Thu Mar 11, 2010 3:28 pm
by mikeonb4c
missfixit70 wrote:mikeonb4c wrote:missfixit70 wrote:So you did get it hot then, that's ok.
Indeed I did
And in rather less than 30 mins
Maybe me and Ronhud just have very healthy stats
Or maybe we're about to wreck our Bongos
Not being pedantic or owt
but I just looked through the "official" workshop manual bleed procedure in the fact sheet, if you follow it as it says, the minimum it should take is @48 minutes up to @60 minutes.
Broken down - 10 minute idle, 6 minute revs (extra 3 if bottom hose cold), 4-5 x 8 minute cycles of revving & idling.
30 minutes suggests it hasn't been bled proper from that.
I'm not at home so can't check the manual but 4-5 x 8 minute cycles doesn't sound familiar. I did try and type up what the translated Mazda workshop manual said and put it on here some time back. If I've typed it correctly it says (inter alia):
16.Start the engine and idle for approximately 10 minutes to warm up
Caution
If any of the following phenomena occurs, stop the engine to lower the water temperature as filling is incomplete. After water temperature is lowered, repeat steps from (15)
(1) Water temperature rises too high
(2) Cooling fan operates
(3) Steam comes out constantly from the air bleed hose
17. Perform the following operations after the engine is warmed up
(1) Keep the engine running at 2500rpm for 6 minutes
Warning
When checking the lower radiator hose (radiator side), be aware of burns or getting caught in the cooling fan.
(2) Check the lower radiator hose (radiator side) is warm. If it is cold, keep the engine running at 2500rpm for 3 minutes, then check again if the radiator hose is warm.
(3) Fill with coolant up to the radiator reservoir tank flange surface
Warning
When attaching the air bleed hose plug, the air bleed hose should be facing upwards as it could cause a burn if it leaks on you
(4) Attach the air bleed hose plug as shown in the diagram
(5) Attach the reservoir tank cap
(6) Keep the engine running at 25000rpm for 5 minutes
(7) Keep the engine idling for 3 minutes
(8) Keep the engine running at 2500rpm for 5 seconds then return to idling status. Repeat this 4 to 5 times.
18. Stop the engine and check the coolant level after coolant temperature has lowered.
Which I think (though my arithmetic is poor) would give about 28.5 mins max (10+6+3+5+3+0.5) or 24.5 if all goes well (10+6+5+3+0.5 - as it did with me and Ron). The warm hose check is conducted after 16 mins, which is where we came in.
I wonder who wrote the factsheet on our website . I recall Ron having something with him printed off from our site when he arrived and that we soon discovered it was not telling quite the right story, so we decided to go with Mazda's advice and discarded it.
There has been more than one occasion where our factsheets have been either incomplete or wrong. It is one of my bigger concerns with our site i.e. that people elect themselves as experts, enshrine their view in a factsheet, and newcomers trustingly follow it, possibly at risk to themselves (I think the tyre loadings factsheet was just one case in point)
Re: Just a thought
Posted: Thu Mar 11, 2010 4:32 pm
by mikexgough
I always allow an hour or so to bleed..... just in case of mishaps..... I'm not in the market to split hairs of how long it takes/should take/bleeding method etc......for me It's not bled until the air is out and the bottom hose is giving out sufficient heat, enough to indicate that the stat to have opened.....
Re: Just a thought
Posted: Thu Mar 11, 2010 4:36 pm
by mikexgough
mikeonb4c wrote:There has been more than one occasion where our factsheets have been either incomplete or wrong. It is one of my bigger concerns with our site i.e. that people elect themselves as experts, enshrine their view in a factsheet, and newcomers trustingly follow it, possibly at risk to themselves (I think the tyre loadings factsheet was just one case in point)
Re: Just a thought
Posted: Thu Mar 11, 2010 4:40 pm
by mikeonb4c
mikexgough wrote:I always allow an hour or so to bleed..... just in case of mishaps..... I'm not in the market to split hairs of how long it takes/should take/bleeding method etc......for me It's not bled until the air is out and the bottom hose is giving out sufficient heat, enough to indicate that the stat to have opened.....
I agree. Ron and me allowed 1.5hrs for each car to allow for the really difficult bits like getting the bung out the bleed pipe
