M54 cooling system refresh - Any other 'while you're in there' jobs?

[DaveP]

The car is off in to have RTABs and LCABs swapped over to polybushes, so I thought I'd take the opportunity to refresh the cooling system (and replace what sounds like a dying pulley). I'm replacing the following parts, and I wondered if there's anything else worth doing while the garage has the front end apart?

- Nissens rad
- Genuine expansion tank
- Meyle metal water pump
- Mahle thermostat
- All three pulleys and tensioner
- Belt

It's has Vanos and DISA recently, and (surprisingly) has no oil leaks. What else is worth looking at while getting this lot done?

[enuff_zed]

The hoses have o-rings inside that flatten over time. There is a chance that they may not reseal so consider getting new hoses as well.
That only leaves the temp sensor, which fits into the top of the lower radiator hose. If you are swapping the hose then you may find it better to fit a new sensor at the same time.
You say 'belt' in the singular. There is of course a second one that drives the AC compressor. Get that done too. Takes about 2 minutes to swap.

[bigwinn]

Have you replaced the oil filter housing gasket? While you have the access in the front I’d change up one of those as they invariably lose the seal and leak

[DaveP]

Have you replaced the oil filter housing gasket? While you have the access in the front I’d change up one of those as they invariably lose the seal and leak

It's been done.

[DaveP]

The hoses have o-rings inside that flatten over time. There is a chance that they may not reseal so consider getting new hoses as well.
That only leaves the temp sensor, which fits into the top of the lower radiator hose. If you are swapping the hose then you may find it better to fit a new sensor at the same time.
You say 'belt' in the singular. There is of course a second one that drives the AC compressor. Get that done too. Takes about 2 minutes to swap.

The second belt was the one thing I was on the fence with. On reflection, I don't really know why. I'll get it ordered.
RealOEM suggests 4pk863, but the Gates branded alternative is 860. Would the 3mm make a material difference?

I'll give the garage a brief on the hoses, but the only OEM options I could find seemed ruinously expensive! Are any of the OE options worth buying (Gates is the only brand I recognise)?

[enuff_zed]

The hoses have o-rings inside that flatten over time. There is a chance that they may not reseal so consider getting new hoses as well.
That only leaves the temp sensor, which fits into the top of the lower radiator hose. If you are swapping the hose then you may find it better to fit a new sensor at the same time.
You say 'belt' in the singular. There is of course a second one that drives the AC compressor. Get that done too. Takes about 2 minutes to swap.

The second belt was the one thing I was on the fence with. On reflection, I don't really know why. I'll get it ordered.
RealOEM suggests 4pk863, but the Gates branded alternative is 860. Would the 3mm make a material difference?

I'll give the garage a brief on the hoses, but the only OEM options I could find seemed ruinously expensive! Are any of the OE options worth buying (Gates is the only brand I recognise)?

I use mostly Gates for belts and hoses tbh. I think the hoses are around the £30 mark from what I recall (each).
Failing that Febi Bilstein are ok as well.
3mm on the belt length will easily be taken up by the tensioner. Tbh, it'll probably stretch that much in the first couple of months.

[DaveP]

The hoses have o-rings inside that flatten over time. There is a chance that they may not reseal so consider getting new hoses as well.
That only leaves the temp sensor, which fits into the top of the lower radiator hose. If you are swapping the hose then you may find it better to fit a new sensor at the same time.
You say 'belt' in the singular. There is of course a second one that drives the AC compressor. Get that done too. Takes about 2 minutes to swap.

The second belt was the one thing I was on the fence with. On reflection, I don't really know why. I'll get it ordered.
RealOEM suggests 4pk863, but the Gates branded alternative is 860. Would the 3mm make a material difference?

I'll give the garage a brief on the hoses, but the only OEM options I could find seemed ruinously expensive! Are any of the OE options worth buying (Gates is the only brand I recognise)?

I use mostly Gates for belts and hoses tbh. I think the hoses are around the £30 mark from what I recall (each).
Failing that Febi Bilstein are ok as well.
3mm on the belt length will easily be taken up by the tensioner. Tbh, it'll probably stretch that much in the first couple of months.

Roger that. Car goes in on Monday, so I'll see if I can get them ordered in time.

[BumpyZ4]

I've had "Rein" upper and lower radiator hoses on mine for the last few years with no issues.

[DaveP]

The hoses have o-rings inside that flatten over time. There is a chance that they may not reseal so consider getting new hoses as well.
That only leaves the temp sensor, which fits into the top of the lower radiator hose. If you are swapping the hose then you may find it better to fit a new sensor at the same time.
You say 'belt' in the singular. There is of course a second one that drives the AC compressor. Get that done too. Takes about 2 minutes to swap.

The second belt was the one thing I was on the fence with. On reflection, I don't really know why. I'll get it ordered.
RealOEM suggests 4pk863, but the Gates branded alternative is 860. Would the 3mm make a material difference?

I'll give the garage a brief on the hoses, but the only OEM options I could find seemed ruinously expensive! Are any of the OE options worth buying (Gates is the only brand I recognise)?

I use mostly Gates for belts and hoses tbh. I think the hoses are around the £30 mark from what I recall (each).
Failing that Febi Bilstein are ok as well.
3mm on the belt length will easily be taken up by the tensioner. Tbh, it'll probably stretch that much in the first couple of months.

Struggling to find the longer hose in stock in time, annoyingly. This one might have to wait.