Mk3 Oil Cooler wires

[gazpowells]

hi

i,m fitting a oil temp gauge into my car 2.0 16v ABF

there is 3 wires coming out of the oil cooler and was wondering does anyone know
which is the temp signal wire?

thanks   

[rubjonny]

there is a spare hole on the back side of the head, fit it here

[gazpowells]

there is a spare hole on the back side of the head, fit it here

thanks mate

[Paul86S2]

there is a spare hole on the back side of the head, fit it here

If I fit my oil temp sender in this hole (at the back of the head) am I likely to block the oil passage if the aftermarket sender is too long?

Cheers

Paul

[rubjonny]

would have to be pretty long to block it, id be more worried about bottoming it out.  The thread on a VW sensor is about 1cm long

[Paul86S2]

would have to be pretty long to block it, id be more worried about bottoming it out.  The thread on a VW sensor is about 1cm long

Thanks. Yes the sensor is too long to fit into this hole, it seems that most aftermarket temp sensors will be too long. Looked at T pieces to fit into the existing temp sensor hole and the sensor is too long for these as well. I was also advised not to fit a temp sensor into a T piece because it won't get the oil flow to give an accurate reading, ok for pressure sensors but not temp sensors.
You can't add an extra wire to the existing MFA temp sensor because this upsets the MFA reading which apparently also reads the volts back from the gauge.
So I have sourced a sump plug adaptor which will allow the temp sensor to be fitted into the sump plug.

Cheers

Paul

[rubjonny]

its the other way round, temp sensors are ok in a t pice but pressure sensors may get a false reading ifput in one, pressure sensors rely on being in direct  contact with pressurised oil, temp snesors will get heated up ok as long as they get at least some oil flow
This is the very reason the 2 pressure warning switches are on the filter housing and the mfa temp sender is all the way up on the back of the head

[Paul86S2]

Just goes to show you can't trust all that you're told. Both Merlin Motorsports and Demon Tweeks told me not to fit the temp sensor to a T Piece, and the Demon Tweeks catalogue states that their T pieces are not to be used for oil temp gauges but they are oil pressure gauge fitting t pieces.
I'll take your advice over theirs though.
It'll be interesting to see if the oil pressure gauge works properly tomorrow when I fit it with the T piece - fingers crossed.

Cheers
Paul

[rubjonny]

ideally id not use a T at all, its never going to be perfect either way.  Best one to use if you need one is the proper VW G40/G60 T piece for the G-Lader oil feed. Not easy to find 2nd hand and VW charge a pretty penny!
Given the choice I'd go with the sump plug option, over one of the D-tweaks T pieces, and use an audi dual pole pressure sensor so as to keep the pressure senders in the factory location

[Paul86S2]

Quick update.
Got the sump plug adaptor to fit the oil temp gauge, so will wire that up next time I change the oil.

T piece fitted for the oil pressure sensor. This seems to work ok. Had some dodgy readings to start with so swapped the earth connection into the engine bay and this has sorted out the random readings.

Oil pressure seems to be fairly constant at idle once warmed up, but shows a drop when you turn on the lights, or use anything else electrical like the brake lights. Is this normal? I am thinking its due to the extra load on the engine whilst working the electrical appliances - or am I talking out of my a*se.

Cheers

Paul