Engine temp rise after shut-off

[llitvack]

Thanks for this suggestion.
I will ask the mechanic the question about Mazda/aftermarket thermostat. It's clear to him and to me, though, that the engine is not overheating. There is pressure in the hoses, and the system is not leaking
If it is indeed operating at a higher temperature, is that a problem, or does the Bongo need to operate at 87-90 degrees?
Good wishes from Leon

[Bongolia]

Was it a genuine Mazda thermostat or a pattern part? If a pattern part, maybe it is operating at a different (higher) temp.

Second that.
Did you put any additive in as you had planned?
Where does the Haydn pick its reading up from is it in the waterway? If no has it been dislodged and refixed in a different position?
Are the fans kicking in OK?

[llitvack]

Hi folks.
The replacement was an aftermarket thermostat, which the mechanic claims opens at the same temperature as the old one.
After reading this thread

http://igmaynard.co.uk/bongo/forum/view ... =3&t=39193

I'm starting to,think that an original Mazda thermostat might lower the operating temperature. I haven't checked the fan yet.
Also, in response to bongolia, we did put in an additive.

Comments anyone?

[Bongolia]

Yes I think thats a good idea to swop out that stat.
Is it possible that the temp pick up position has been moved/disturbed or is it in the water way?
What additive, was it the K thingy?
It would be interesting to know what temp the fans cut in at too.

[windywatson]

Re the coolant additive/leak stop. If you checkout the system and find & fix the leak then an additive wouldn't be a good idea. They are really intended as a get out of jail card if you spring a leak & want to stop it until you can effect a repair.
If you run with a leak stop additive as normal and your vehicle develops a leak you wont know. In my book it is important to know if there are any parts of the coolant system that are starting to fail so that you can get it fixed. Otherwise you may find that when you do find out its turned into a catastrophic leak just when you don't want it. That's why members install low coolant alarms, a much better solution to monitoring the coolant situation.
The same applies to running tyres with an additive to seal punctures, if your tyre is damaged but the damage is not evident because the air leak is stopped, you may be running around on a ticking time bomb. I used a sealant in my tyres as the van is LPG & I don't have a spare. I was advised against this by the technical officers of the Caravan Club because there had been instances of tyres running with large nails through the tread unbeknown to the driver until major failure.

Cheers

[llitvack]

Dear WIndy,

That's good advice; thank you.
I'm going to change the water pump and thermostat (and, of course, the coolant), with the hope that the engine will run somewhat cooler. The leak stop fluid will, therefore, be drained out as well.
Yet I still wonder if it is problematic for a Bongo engine to run at 95-97 degrees after the thermostat opens?

Good wishes from Leon

[mikeonb4c]

Dear WIndy,

That's good advice; thank you.
I'm going to change the water pump and thermostat (and, of course, the coolant), with the hope that the engine will run somewhat cooler. The leak stop fluid will, therefore, be drained out as well.
Yet I still wonder if it is problematic for a Bongo engine to run at 95-97 degrees after the thermostat opens?

Good wishes from Leon

My concern about leak stop additives etc is whether they may coat/silt up the narrow channels in the radiator matrix. Whilst draining to fit new thermostat and water pump i wonder if there's a practical way to check freeness of flow through the radiator(s). But, quite likely, it might be the thermostat that's causing the issue. Most car owners would never know about that since they don't hav an engine block temp monitor.

[cmm303]

Dear WIndy,

That's good advice; thank you.
I'm going to change the water pump and thermostat (and, of course, the coolant), with the hope that the engine will run somewhat cooler. The leak stop fluid will, therefore, be drained out as well.
Yet I still wonder if it is problematic for a Bongo engine to run at 95-97 degrees after the thermostat opens?

Good wishes from Leon

Certainly put in a genuine Mazda thermostat.
If there has been leak stop in, I'd give the system a thorough flush and reverse flush the rad and both heaters. Draining alone leaves quite a bit behind.
It might bring back your coolant loss problem if that wasn't properly identified and fixed.

Running at 95-97 shouldn't be a problem but obviously less margin if that is "normal".
The rad fans come on at a buttock clenching high temp (I think that was Northern B's description ). I tried testing mine on the drive and wimped out - I don't have a head temp gauge but my modified standard gauge was heading for the H tick, equivalent to around 100-105, very approx. (I knew the fans worked, having tested them with resistors in lieu of the sensor, and measured the sensor resistance). I'm not sure if the actual trigger temps have been stated here but they are designed to come on only when the cooling system is running flat out and not coping, first at slow speed then high speed.

[Northern Bongolow]

to take some of the guess work out of this leon buy one of these below and have a play.

http://www.ebay.co.uk/itm/Handheld-Non- ... SwrklVe5uw

[Bongolia]

Where does the Haydn pick up its temp reading from, just interested to know.