1) My car shows "Coolant low level" light.
LR3 user posted his youtube which shows he recommends replacing the coolant reservoir because it has a buoy sensor.
Is there any other way to fix this light? Coolant is enough in my tank.

2) Spark plugs
Is it fine for me to use any iridium spark plugs?
Or do you recommend the OEM ones?

3) O2 Sensor
Is there any reliable substitute instead of the OEM (Walker one)?

Thank you in advance!!

 

The sensor is most likely failed. There are two parts...

1) A magnetic sensor which clips in to the bottom of the reservoir and has an electrical connector. This is cheap and easy to replace but is most likely *not* the problem.

2) A buoyancy float inside the reservoir. This is most likely the problem, and you do need to replace the tank. It's actually not very hard to do, basic tools.

I use Denso Iridium 4704 TT (3.2L i6 engine). Any reputable brand which is spec-ed for the vehicle should be fine. If you don't like the performance, you can always try something else.

Don't know. If your engine is the 3.2 i6 the entire power train is volvo, so you can often shop volvo parts for a better price.

 

hmmm. maybe. but are you certain? I would get a pressure test done and confirm you don’t have a slow leak first.
throwing the dice and swapping parts doesn’t sound very scientific.

 

The reservoir has to get fairly low to trigger the low-level alert. The alert will initially come and go if the float is bad, and will eventually stay on all the time. The float is like foam rubber, it gets saturated with coolant, and just won't float any longer.

If the low level alert is on and the level is near the max then the issue is the sensor. Check it on several occasions, cold and hot, just to be sure there's not level changes due to oil or exhaust gas in the coolant.

But the level float is guaranteed to fail after 10+ years, so that's Occam's razor.

 

More often than not this is caused by a slow leak.

 

That's also entirely possible, assuming the coolant level is actually dropping. The way to check for that is by eyeball, so you can see small changes.

 

 

I found the coolant level is getting below MIN even though I filled near up to MAX one month ago.
What would you recommend to check the leaking in order in case of LR2 2009?

 

I found the coolant level is getting below MIN even though I filled near up to MAX one month ago.
What would you recommend to check the leaking in order in case of LR2 2009?

 

Something like this UV test dye... But you will also need a UV light source. Check under the car to see where it leaked onto the ground and that will tell you where to look in the engine compartment.