At the summit of the picturesque fens
Nope. I have only changed the viscous clutch which made matters worse, as it was stopping the car getting to full temp.
M54 cooling issues. Help. My melon is in overload.
- Thread starter Pondy
- Start date
Both original coolant temp sensors are still connected. My new gauge sensor is fitted in an unused port in the block.
The ONLY original sensors I have disconnected are the two OIL sensors; temp and pressure, which have been replaced with aftermarket that are not connected to the car's wiring anymore.
My other thought is that because I now have no undertrays at the front of the car, air can be pulled (by the viscous fan) up from the underside on the engine side of the rad, so by-passing the rad. There is a 2" gap between the rad and the fan shroud at the bottom.
As the viscous fan 'pulls' air, at standstill (which is the only way I can check all this) it could be pulling enough cool air up to affect the temp of the metallic strip, so the fan isn't speeding up. The electric fan 'pushes' air over the rad as it's mounted on the front, so isn't affected by any air 'leaking'.
When the car is moving the above presumably won't be a problem, as air will be pushed over the rad through the grille.
All I am trying to ascertain is whether A) my viscous fan operates as it should and B) if my thermostat is 'leaking by' before it opens.
So far, I am no closer to finding out either. Changing the viscous clutch for a new one was a waste of time (and money) as it turns out.
I still think I would bin the viscous and rely on the electric fan tbh.
I may have misled you. The donor car was a Z3, not Z4
I still have a cooling issue. Viscous fan aside.
I took the car on a 30 mile run today to see what is going on with the old viscous fan back in place.
The ambient was around 14c.
It took almost all the 30 miles for the car to get up to normal operating temperature. It got there, but it took an age.
I am thinking the thermostat is 'leaking', or 'letting by'. Does this make sense?
I presume the 'stat has a rubber, or fibre, seal internally, but don't know. If it has, it wouldn't surprise me if it has perished, as the car hasn't been used for over two years until very recently.
I just want to be fairly sure before I change the stat and have to deal with the coolant system afterwards. My experience with coolant previously didn't go well!
I took the car on a 30 mile run today to see what is going on with the old viscous fan back in place.
The ambient was around 14c.
It took almost all the 30 miles for the car to get up to normal operating temperature. It got there, but it took an age.
I am thinking the thermostat is 'leaking', or 'letting by'. Does this make sense?
I presume the 'stat has a rubber, or fibre, seal internally, but don't know. If it has, it wouldn't surprise me if it has perished, as the car hasn't been used for over two years until very recently.
I just want to be fairly sure before I change the stat and have to deal with the coolant system afterwards. My experience with coolant previously didn't go well!
When I got my car it used to take nearly the whole 8 miles my commute to work took to get upto temp, once i changed the thermostat it went down to about a mile.
Never had any codes, my conclusion was the thermostat wasn't closing properly or not sealing and allowing coolant into the radiator.
My thermostat and the port into the engine was covered in hard deposits of coolant probably from it been filled with tap water and the wrong coolant for the engine, I would replace the thermostat to rule it out.
Never had any codes, my conclusion was the thermostat wasn't closing properly or not sealing and allowing coolant into the radiator.
My thermostat and the port into the engine was covered in hard deposits of coolant probably from it been filled with tap water and the wrong coolant for the engine, I would replace the thermostat to rule it out.
Attachments
Thanks. The pictures are very useful.
Sounds exactly like a lazy or stuck open thermostat. Common failure mode.
Update:
It was a leaking thermostat AND a knackered viscous clutch.
After spending many hours (make that days) monitoring and checking; if you have an M54 engine with a viscous clutch....DO NOT GET RID OF IT!
Deleting a viscous is not a good idea. The electric fans on these are set to be 'emergency' only and are just single speed.
If you delete a viscous and rely on the electric fan, the car will run too hot!
It was a leaking thermostat AND a knackered viscous clutch.
After spending many hours (make that days) monitoring and checking; if you have an M54 engine with a viscous clutch....DO NOT GET RID OF IT!
Deleting a viscous is not a good idea. The electric fans on these are set to be 'emergency' only and are just single speed.
If you delete a viscous and rely on the electric fan, the car will run too hot!