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Is my temp gauge too high?
Posted: 12 Nov 2020, 09:30
by Ciaoflyer
DJ 2.1 temp gauge gets up to 3/4 before any fans come on. The Van seems not to be over heating and cooling system works as it should, no leaks and fluid goes up and down in the tub behind the rear flap. However, before I rebuilt the engine needle only went to half way before fans kicked in but the system was pressuring due to cylinder head seal hence rebuild.
My question is should the needle go so high, it sits a 3/4 on idle, then comes down a tiny bit, goes back to 3/4 and then slow fan comes on.
Could it be a earth problem as all sensors have been replaced including 2 speed switch in rad. Both speeds work. If I put headlights on it goes even higher but comes down if I switch off. Red light never flashes.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 09:50
by TONYT25T25
Interesting about the headlights affecting the temperature gauge, I noticed that my temperature gauge also increased when I put my sidelights on, haven't found out yet why or if it is an issue, my gauge under normal conditions only wanders past the midway part when stuck in traffic on a hot or warm day.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 10:38
by ZsZ
clean ground connections at the engine, gearbox and behind fuse panel together with steady ~14V at the fuse panel while the engine is running is a key to an accurate temperature gauge
however your statement that the fan comes on on this stage can assume that the gauge is correct but your engine runs hot.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 10:47
by Ciaoflyer
ZsZ wrote: ↑12 Nov 2020, 10:38
clean ground connections at the engine, gearbox and behind fuse panel together with steady ~14V at the fuse panel while the engine is running is a key to an accurate temperature gauge
however your statement that the fan comes on on this stage can assume that the gauge is correct but your engine runs hot.
Thanks for this, how do I make my engine run cooler?
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 10:59
by ZsZ
First be sure that your temperature is actually high or not.
Measure the pipes in the engine bay with an IR thermometer and clean the electrical connections (ground points, temp sender connectors, +ve connectors from alternator to fuse panel) to have accurate gauge.
If the high temperature is proven then you have to address that.
Unfortunately I am not an expert on petrol so cannot help you in that but bad timing can cause overheating AFAIK
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 11:13
by DoubleOSeven
Swap out the 87C thermostat for an 80C one.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 14:23
by Ciaoflyer
Ok, cleaned all earth points and voltage at fuse box reads 13.89. I have reset timing and it now seems to be running cooler, when driving needle sits here... is it still hot?
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 15:05
by TONYT25T25
A bit more information that may put your mind at rest, presume all coolant tanks are at the level they should be, also found this from a previous thread which may help
1. The flashing red light in the temp gauge has two functions.
a. If the gauge is above 3/4 and is flashing it means overheating
b. If below 3/4 and flashing it means the coolant level in the header tank is low.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 15:18
by Ciaoflyer
TONYT25T25 wrote: ↑12 Nov 2020, 15:05
A bit more information that may put your mind at rest, presume all coolant tanks are at the level they should be, also found this from a previous thread which may help
1. The flashing red light in the temp gauge has two functions.
a. If the gauge is above 3/4 and is flashing it means overheating
b. If below 3/4 and flashing it means the coolant level in the header tank is low.
Thanks for this! Light only flashes when ignition switched on and then goes off, all coolant levels are at correct level.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 15:49
by Mocki
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 16:43
by Ciaoflyer
Mocki wrote: ↑12 Nov 2020, 15:49
This is perfect, thank you! Never seen this, certainly put my mind at rest!
Where is this from?
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 18:22
by Mocki
It’s from the VW T25 owners handbook that would have lived in your glovebox when the van was new .....
That said, the gauge takes the reading from the sender , which can be different resistances , I changed one in one of ours just because I changed the water pump and it reads three needles widths higher , swapped back and gauge back where it used to be ....
Headlights affecting the level suggests either dirty earths or voltage regulator on the dash is faulty
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 19:47
by Ciaoflyer
Mocki wrote: ↑12 Nov 2020, 18:22
It’s from the VW T25 owners handbook that would have lived in your glovebox when the van was new .....
That said, the gauge takes the reading from the sender , which can be different resistances , I changed one in one of ours just because I changed the water pump and it reads three needles widths higher , swapped back and gauge back where it used to be ....
Headlights affecting the level suggests either dirty earths or voltage regulator on the dash is faulty
I changed my sensor when I rebuilt engine in the summer and it reads higher than the old, if I can find it may swap back. Where is voltage reg on dash?
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 19:51
by Ciaoflyer
Ok, found voltage reg on brickwerks! Cheap so may replace.
Re: Is my temp gauge too high?
Posted: 12 Nov 2020, 20:02
by TONYT25T25
Must remember this information ref voltage regulator when I get round to sorting mine out, is this the one quoted on Brickwerks which has to be adapted to fit?