On Monday this is booked in for some major fettling. Cambelt, aux belt, tensioners, water pump and thermostat. Part of my investment into this to make sure it lasts a long time. Always risky giving a Laguna too much attention though.
In the meantime, I decided to change the plugs today. Cheap enough and I have no idea when they were last done. Idle is a tad unstable too.
Bonnet up
Tiny little engine cover off
Coil plugs off. Plastic tube covering the wires is very brittle at this age
Coils out
Plugs out
Look a decent colour. Gotta love fuel injection to keep things running sweet. We really do take it for granted nowadays
Electrode is pretty worn though. Main dealer service history on this
Coils are a known weak point around this age. They are original too (Week 26, 2002)
Denso though
Obviously being of Japanese manufacturer, they are of good quality. Sagem were the troublesome ones according to Renault
//cloud.tapatalk.com/s/5da2547c20c6f/4242A.pdf
Next up is the climate control. It seems to have two modes. Minimum temperature (16c indicated) gives full cold. One notch above (16.5c) it gives full hot. The engine coolant thermostat is broken at the moment so that's bareable. However once Mondays work is done, it's going to get very unpleasant. So I decided to have a look.
A common issue with these is either the exterior temperature sensor or the interior sensor. Exterior is fine as it's reading a realistic 11 celicus on the big screen. Interior I did some diagnosis.
It lives up behind the rear view mirror
The blue bead is the temperature sensor and the white cylindrical object is a humidity sensor. There is a little fan behind which forces air over this
Getting it apart required judicial force to prise the middle
Which after some delicate bending, got it split
Quite a simple circuit. Solder joints look good. Material coating is conformance coating, this prevents corrosion
Checking the temperature sensor with a Multimeter gave sensible values. A common type is 10k ohms at 25c. Breathing over it brings the resistance down to around 7k. This corresponds to roughly 35c. Quite acceptable
So I had a check of the climate control panel. Like most Renaults of this era, it's mostly held together with plastic tabs. Pulling the card reader out required no screws removed. Climate panel had two plastic to be gently bent and the panel pivoted out.
Top side looked good
Bottom panel looked all good too
Hmmmm
Some more Googling found that there is three temperature sensors in this system. Exterior, interior and a evaporator temperature sensor. Interesting!
Now I wouldn't have immediately thought the evaporator sensor would be a problem as it goes to these extremes with the Aircon off. Either way I thought I'd have a look.
The sensor lives in the passenger footwell behind a plastic kick panel. A twist and a pull was all it took to remove. Then the connector gently pulled back to disconnect.
So did it do anything? You bet it did! With it disconnected, I can hear the mixer flaps progressively move now as I turn the temperature up. Running around the block seems to show it works properly now!
Only on a Renault can you properly fix electrical problems by disconnecting and removing things...
I'll probably get another one as when I've got the Aircon regassed, the system will need it to properly regulate the temperature. I believe the evaporator must never go below freezing point otherwise things don't work properly. So in cold weather especially, this sensor should stop that happening.
Probably be a dealer part if they still do it. They're getting of the age now that Renault is stopping parts support. eBay doesn't bring up much either, apart from a few international sellers or some manky and expensive UK breakers.