She's back!!! Still running a little cool though..

[tony_ack]

My Golf has been at the garage for the last couple of weeks having the various jobs done that I've been moaning about!

Missed her greatly 

FINALLY got the rev counter sorted - turns out it was the coil signal wire AND the clocks - no wonder I was having trouble finding the problem. The rev counter needle over-reads by about 200rpm compared to the digital counter on the MFA, but it's a start at least...

It feels smoother, quicker and more responsive, but this may be because I've taken off the loud rude-boy exhaust and got a working rev counter - my mind is probably playing tricks on me.

It was running very cool before - just above cold on the gauge. Turns out, as suspected that the thermostat was stuck open. New thermostat now, and the system's been flushed, but it still doesn't get above 1/3 the way up the gauge (the last line before centre), despite the fact that the previous owner has stuck loads of cardboard behind the grille to keep the heat in. The MFA reads a nice healthy 102 for the oil, and the coolant temp needle is steady at 1/3, so I'm wondering if it could be a faulty sender, or under-reading gauge?

If not, what else could it be? Thermostat was a VAG part.

[rubjonny]

sounds like the gauge/sensor to me, since the mfa reads nice n hot. the sensor is eaither a 2 pin push fit black one, or a single pin threaded black depending on the age of the car, either way it'll have a yellow/red wire. try bridging/earthing the pins, see what the gauge does. it should shoot to max

could be the rev counter and temp problems are related?

[tony_ack]

Actually, maybe you're right, re the rev counter/temp gauge problem being related. The over-read from the rev counter is coming from somewhere - when I tested previously the voltage going to the rev counter increased as the electrical load on the battery increased. Hopefully the issue isn't in the clocks, as I don't fancy taking them out again. I might try plugging in a spare set and seeing what happens

[rubjonny]

worth a try, in the past ive taken dash undertray out and pulled the plug from there, had clocks sat in my lap for testing

[tony_ack]

Sorry to reopen an old thread, but I've only just got around to testing the clocks!

Turns out that the clocks were the cause of the rev counter overread AND the temp showing as cool. Rev counter is now pretty accurate compared to the digital counter and the temp gauge sits bang in the middle.

I guess the lesson is to rule out temp sender and gauge issues if you think you are suffering from cooling problems.

She's all put together again now, and ready to go - dash out and back in again in less than an hour, with everything working! I only wish all my mornings working on the car were so productive..