New? Start here. See the forum's active topics. Say hi contact Matthew.
This Amazon link helps MVS!

2000 V40 Temp Gauge Erratic and Engine Surging

Let’s talk 2000 V40 Temp Gauge

The new temp. sensor (ECT) did the trick – cured all of the temp. gauge problems. My only current problem is a P0128 OBD check engine code. My research suggests that the problem is probably an aging thermostat. I’ll ignore it for awhile and see what happens.

2000 V40 Temp Gauge Erratic and Engine Surging

Bonus! More on the Volvo V40

The Volvo V40 is the compact premium hatchback that’s perfectly suited to modern life. Clean, contemporary lines and a youthful character make the V40 a car to be enjoyed, every day, with smart technology that supports you and makes life easier. A responsive chassis puts you in control and inspires confidence on any road, while the cabin’s exquisite craftsmanship and exceptional comfort embody Volvo Cars’ distinctive Scandinavian design.

Bonus! Volvo Facts

  • Volvo has always put people first. Assar Gabrielsson and Gustaf Larson founded Volvo on the idea that “cars are driven by people. The guiding principle behind everything we do at Volvo, therefore, is and must remain safety”. We still believe that today. Our Vision 2020 personifies this. Our goal is that, by 2020, no one should be seriously injured or killed in a new Volvo.

Subscribe to the MVS Newsletter

The MVS Volvo Newsletter is a once-a-month email delivered to your email. It’s simple to unsubscribe at any time if you change your mind.

Visit The Official Volvo Cars Website


2000 US model V40 turbo 1.9 with 78k.

Erratic temp gauge, fan cycle one comes on at 3/4 and fan cycle 2 kicks in when close to red and stays there.

Fan cycle 1 comes on when car is turned off for 6-8 min. This can drain battery quickly.

Disconnect the temp sensor. This stops the cycle 2 fan, but not the cycle 1 fan.
I would disconnect the negative lead to battery after you get home if you cannot repair it for a few days.

Took original temp sensor off. Put in cheap $15 replacement. Mistake! Same symptoms started about a few days after.

Could the cheap part fail that quickly? YES!!

Went to dealer. Paid $55 for part.
All symptoms have cleared for now. Apparently they break quiet often and aftermarket on this part is not recommended.
Make sure you have blue silicon based coolant in the car as this can ruin the sensor.
Pentofrost NF or Volvo coolant.

Its a good idea to replace the 90degree thermostat and seal if its been more than a couple of years.

Leave a Reply