Thermostat Change
Today the weather has been mild and dry, so I’ve seized the opportunity to get things done. I cycled (yes, cycled!) to Vines of Guildford to collect all sorts of goodies: for the 330d a new leather lift strap for the boot floor and an oil filter kit, and a new thermostat and coolant for the M5. The 330d has 8,000 miles to go until its next service, so in about 1,000 miles time I’ll give it an interim oil change, but more on that as and when I do it.
The M5’s temperature gauge has struggled to get above the lower ‘norm’ dot recently, so I figured a new thermostat should help. As mentioned in a previous post, I followed the instructions on an M5 board, which were really useful. The biggest pig was removing and then refitting the under engine belly panels, necessary to drain the coolant. Once that was done, the MAFs and associated tubing had to be removed to permit access to the thermostat housing.
Then the coolant pipes were removed and the casing lid could be released. The instructions said “Remove thermostat housing (tug it! hard because VANOS sending unit in the way and doesn’t like to move due to SS hoses)” – tug it hard is an understatement, it required levering with a breaker bar! Still, eventually it was done.
Then the thermostat was changed, and as ever refitting was the reversal of removal.
This sad thing is that while the temperature needle now sits closer to upright than it did, it’s still not perfect and I suspect the improvement is as much down the milder weather than the new thermostat! Still, at least I’ve tried and I’ve got nice fresh coolant on board – I’ll have to do more reading before chasing this problem again.
Hi Neil.
My ’00 is just the same. It does take a while to warm up the coolant but when it is it only sits just above the first ‘cool’ dot as you say.
According to M5 board, this si the norm. In the hidden menu the coolant should sit at 79C, I only ever get this in mild weather though. Sounds as though yours did need doing, it just behaves normally now, which is on the cool side.
Neil
Now that we’ve had another cold snap I’m happy that replacing the thermostat has definitely improved matters – but it just isn’t bolt upright like my 330d. I’ll dig down to the hidden menu at some point and check it out.
Yes I recall my M3 Evo warming up within half a mile and being utterly vertical no matter the conditions.
The coolant, according to test 7 on the dash was 75C in about 2C outside temp whilst on the motorway today.
Once near home and more stop/start it rose to between 77-79C (the latter being 1mm or so off to centre left).
May be of interest owing to similar outside temps.
Thanks for posting this info Neil, I’ll try and remember to check mine when I next wake the beast from its slumber!