Club 80-90 Forums

Hi all,

I recently bought a well looked after1986 Reg T25 that had a Subaru conversion done in 2014 with a pre 2003 Legacy engine.  It's done 5k since the conversion.  It was used only occasionally by it's previous keeper and kept indoors.

I'm using it more regularly but have noticed that the engine temp reads about 3/4 of the way across the dial.  It never budges from this once it's warmed up.  The red flashing coolant light flashes when I restart the engine after having turned it off for a few minutes.  A good example would be when I fill it up. It does it when the engine is cold or warm.  Today it flashed for over 25  miles of driving before eventually going out.

Coolant levels are good and I can hear the fan kicking in and out.  I can see in the paperwork that a new temp sender was dropped in last year.

It has the additional chicken switch and even with that on, the needle never drops below the 3/4 marker.

Anything to worry about or check?

Cheers

Feel the hoses and get a laser thermometer to check actual engine temp, mismatches sender and gauges can be unreliable but if the gauge is steady it’s most likely the temps fine

The only thought I have is a dirty or tired coolant shortage sensor...
Or a shortage indicator module playing up.

But as said already, if it behaves well, and doesn't sneak past the 3/4 mark, then I would not worry.

The gauge is just a guide, not an exact reading of the true engine temperature.
It is easy to become paranoid about these vans.
You just need to balance yourself at a healthy level of paranoia, just so that you don't become complacent.

davidoft1 wrote:Feel the hoses and get a laser thermometer to check actual engine temp, mismatches sender and gauges can be unreliable but if the gauge is steady it’s most likely the temps fine

Perfect thanks, I'll dig out the thermometer

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Robsey wrote:The only thought I have is a dirty or tired coolant shortage sensor...
Or a shortage indicator module playing up.

But as said already, if it behaves well, and doesn't sneak past the 3/4 mark, then I would not worry.

The gauge is just a guide, not an exact reading of the true engine temperature.
It is easy to become paranoid about these vans.
You just need to balance yourself at a healthy level of paranoia, just so that you don't become complacent.

Thanks for the quick reply. Having owned many older cars I'm always on the lookout for 'problems' :⁠-⁠) Maybe it's time to just stop and enjoy this one

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Mine has the opposite problem, when cold the needle sits off the gauge and will only ever reach about 1/3 once warmed up. Everything runs well and the temperature reported by OBDII is stable on long runs. I work on the basis that as long as it's consistent then I'm happy.

Is it using the Subaru temp sender or, modified to use to use the VW one?

My loom was done by Subaru Surgery  (2001 EJ25) over a year ago and I think he adds a resistor to the circuit to get the Subaru sensor output roughly in line with the VW gauge but there may be other ways of doing it.  Do you know who did the loom on yours as you may be able to speak to them and see how it 'should' operate?  Mine acts exactly as it did with VW tbh, flashes on start up as a test, then goes off.  Once warmed up needle sits roughly pointing up and is super stable.

As above, get the appropriate cable/app for your ECU, Mine is an early 2001 preOBD2 car doesn't work with ODB readers, I use the VW spec cable with SSM app on phone.  I don't use often, but after the conversion I used it to check/clear errors codes and and verifying sensors working correctly.

Update on this one.  I got it up to operating temp (3/4 on the engine temp again.)  Checked out the engine with my laser thermometer and no part of the engine was over 90c so I've now confirmed that my gauge is just showing around 90C at 3/4.  I can live with that.

I did notice that the coolant tank was absolutely brimmed and on the top of the coolant tank where the sensor goes it, there was a small amount of coolant.  I'm wondering if this was shorting the circuit and causing the flashing coolant light to come on.  I've removed some and will take it for a run later to see if that's fixed it.   

Is the coolant tank filler (behind the number plate) an expansion tank or just for filling?

 

ManicGTI wrote: ↑18 Mar 2024, 09:17 Is it using the Subaru temp sender or, modified to use to use the VW one?

My loom was done by Subaru Surgery  (2001 EJ25) over a year ago and I think he adds a resistor to the circuit to get the Subaru sensor output roughly in line with the VW gauge but there may be other ways of doing it.  Do you know who did the loom on yours as you may be able to speak to them and see how it 'should' operate?  Mine acts exactly as it did with VW tbh, flashes on start up as a test, then goes off.  Once warmed up needle sits roughly pointing up and is super stable.

As above, get the appropriate cable/app for your ECU, Mine is an early 2001 preOBD2 car doesn't work with ODB readers, I use the VW spec cable with SSM app on phone.  I don't use often, but after the conversion I used it to check/clear errors codes and and verifying sensors working correctly.

Not sure who did the loom on this as it was over 10 years ago.  I hadn't realised there was a port on there so am going to go and have a look.  I've got a couple of BT ODB2 senders so will have a play 
 

symbol_soup wrote:Update on this one.  I got it up to operating temp (3/4 on the engine temp again.)  Checked out the engine with my laser thermometer and no part of the engine was over 90c so I've now confirmed that my gauge is just showing around 90C at 3/4.  I can live with that.

 

Now that you've measured it properly with the temp gun, you can relax mine also stays at about 3/4 (my99 ej20). Over the years though as various components have been changed, it has hovered at different locations too. I wouldn't worry about where it is on the VW gauge (it's pretty all over the place on the original wbx engines too). Get to know your van and you'll know when it's not happy

Enjoy the motor!