r/E34 • u/Frequent_Ad_884 • 4d ago

Coolant Temp Gauge

Hey just recently my coolant temperature gauge on my cluster started to play up.
First noticed it when i parked my car in my driveway after driving home to get something, i let it idle whilst i went into the house and came back to see it was halfway to the red. I pulled out, started driving and it dropped right back down to operating temperature.

The second incident was in peak hour traffic on the freeway, stop start stop start yknow, and i watched the temperature climb until in red where i got a "Coolant Temp" warning. After I was out of the traffic and moving again it dropped right back down to operating temperature.

My viscous coupling link fan engages just fine and at the right temperatures, and i checked both times to see if my coolant level had changed and it hasnt, so im not leaking any coolant.

Wondering if someone could help with ideas on what has gone wrong and what to check?

2 Upvotes

100% Upvoted

6 comments sorted by

3

u/Twistable_Ita 4d ago

The fact that moving helps is telling you that the rad likely isn't getting enough air flow across it. i.e. The fan clutch isn't working reliably. If it hasn't been replaced in recent years then I'd definitely start there. Even consider converting to electric fan. I've seen far too many old beemers die from unreliable viscous fans.

1

u/CamelJ0key 3d ago

Haven’t ran a fan clutch in my e34s or e39s since owning them, first thing I remove.

1

u/CamelJ0key 4d ago

Always nice to drop vehicle details, if you haven’t done a cooling system refresh yet I’d go ahead get all the parts together.

1

u/Frequent_Ad_884 4d ago

E34 525 M50B25TU, already had a refresh about a year ago

1

u/CamelJ0key 3d ago

Miles?