Bottled out of Thermostat Job...

[repenttokyo]

there is nothing to fear with disconnecting the battery.

[doogie]

You've got the M30 engine don't you?

Battery disconnect is not necessary, but it's nothing to worry about as long as you know the code for your radio - you'll need to reset the time on your OBC too, but that's about it!

The stat housing on the M30 is metal so no worries there - if it looks ok and the bleed screw is intact and not all chewed up, then just leave it, otherwise get a new one if it's old and horrible.

If you're doing a full coolant drain (you can change the stat without doing one but you should really do one every 2 years or so anyway and flush out with a garden hose) then drain the radiator, then the block, that should get the majority of it out. Disconnecting the hoses can help, but make sure that you don't damage them and that they're not too old and worn with split ends etc.

Do you know the history on your water pump? Might be worth thinking about doing at the same time if you're doing a full drain & flush. I'm paranoid as I had an M20 E34 where the water pump went causing major overheating problems, and my M30 E32 where the water pump went, fortunately without causing too many problems - I had a spare one in the boot in preparation and changed it a couple of days later!

[e34.535i.sport]

So CaptainGoSlow and I were planning on changing the thermostat out Saturday, but when it came to the crunch I bottled it due to a few concerns. Luckily we found a thrust arm bushing (which had been replaced a few months back) was torn so at least we had something to do! [That sorted the wobble on my nearside front wheel by the way... The car feels awesome now!]

Anyway, thermostat concerns...

1). Is disconnecting the battery absolutely necessary? - I've avoided doing this for a long time... Don't know why but I'm very apprehensive about doing it.

2). Should I buy a new housing as apparently it's plastic and can break quite easily?

3). When draining the coolant previously I found that the thermostat housing stayed submersed in the green stuff... Should I just pull the hose at the bottom of the thermostat to get rid of this or syringe it out?

If anyone has some more detailed instructions than on e34.net on how to change the thermo I'd appreciate taking a look at them, or if you can give me any words of wisdom at all. Particularly on #1 and #3.

Thanks guys...

[e34.535i.sport]

You've got the M30 engine don't you?

Battery disconnect is not necessary, but it's nothing to worry about as long as you know the code for your radio - you'll need to reset the time on your OBC too, but that's about it!

The stat housing on the M30 is metal so no worries there - if it looks ok and the bleed screw is intact and not all chewed up, then just leave it, otherwise get a new one if it's old and horrible.

If you're doing a full coolant drain (you can change the stat without doing one but you should really do one every 2 years or so anyway and flush out with a garden hose) then drain the radiator, then the block, that should get the majority of it out. Disconnecting the hoses can help, but make sure that you don't damage them and that they're not too old and worn with split ends etc.

Do you know the history on your water pump? Might be worth thinking about doing at the same time if you're doing a full drain & flush. I'm paranoid as I had an M20 E34 where the water pump went causing major overheating problems, and my M30 E32 where the water pump went, fortunately without causing too many problems - I had a spare one in the boot in preparation and changed it a couple of days later!

Hey there Doogie thanks for taking the time to write that for me, very informative! Just a couple more questions I hope you don't mind...

Yes it is an m30 engine - and the Tstat housing actually looks like stone if that makes sense?!!! I thought it was metal but I heard it was plastic somewhere - it looks ok from the outside so hopefully it shouldn't be a problem.

How do I drain the block? I've drained the radiator before when I changed out all of the hoses so they're all in perfect condition but I haven't drained the block before.

Its a good point you make on the water pump, I might just do that pending on the price as I'll probably go to the dealer for this kind of thing. Actually I'm pretty sure I will now you've got me thinking about it... I'm trying to get the car ready for a long trip in August so I suppose its best to do it while the system is drained!

I do worry about the radio code with the battery, as it's an aftermarket system. Is is ok to change the waterpump without disconnecting the battery too do you know?

Thanks again for your time.

[whiskychaser]

You seen the little gizmos you plug in your cigarette lighter? They provide just enough juice to keep your radio going while you take out the battery.

[doogie]

Hiya, no problems

Yeah, stone makes sense, it's some type of metal and can sometimes go a bit white/ grey with age. Don't know which 5 engines had a plastic cover, the E36 3 has one but you don't need to worry about that.

To drain the block, you need to loosen the plug which is under cylinder 6 - it can be a bit awkward to get to, and I'm pretty sure after spending 10 mins looking for it, I found it while under the car with it jacked up, with a torch in my hand! It will be on the passenger side on a US model - just get under the car with it on jack stands and look under the spark plug closest to the windscreen and the plug is there - hopefully it will be pretty obvious... just don't try and unbolt the exhaust manifold while you're there

Water pump again is no problem with the battery connected, and like you say if you're doing the stuff anyway and don't know it's history it's better safe than sorry!

Depending on what type of stereo you have, it may or may not have a code - hopefully if it does you will have it in your owner's manual folder or somewhere like that. If you do a search on the make and model on the internet you might be able to find out if it requires a code after battery disconnect.

[e34.535i.sport]

Hiya, no problems

Yeah, stone makes sense, it's some type of metal and can sometimes go a bit white/ grey with age. Don't know which 5 engines had a plastic cover, the E36 3 has one but you don't need to worry about that.

To drain the block, you need to loosen the plug which is under cylinder 6 - it can be a bit awkward to get to, and I'm pretty sure after spending 10 mins looking for it, I found it while under the car with it jacked up, with a torch in my hand! It will be on the passenger side on a US model - just get under the car with it on jack stands and look under the spark plug closest to the windscreen and the plug is there - hopefully it will be pretty obvious... just don't try and unbolt the exhaust manifold while you're there

Water pump again is no problem with the battery connected, and like you say if you're doing the stuff anyway and don't know it's history it's better safe than sorry!

Depending on what type of stereo you have, it may or may not have a code - hopefully if it does you will have it in your owner's manual folder or somewhere like that. If you do a search on the make and model on the internet you might be able to find out if it requires a code after battery disconnect.

First of all thanks for the continued advice! Now, I'm back to ask some more newby questions! Can I just make sure that when I drain using the plug under spark plug #6, refilling is via the normal resevoir correct?! I'm probably not going to disconnect the battery, I like taking risks

I'm tempted to replace the Radiator while i'm there now after reading some other posts but I haven't had any issues with it so far so I'll have to have a think about that one.

Oh one nore quite important one - When I change the water pump will I need to use some kind of lube or sealant, or just stick it with the gasket that comes with it?

Thanks again! I'm actually looking forward to the job now, roll on saturday.

[e34.535i.sport]

Hey Whiskey, always a pleasure!

I haven't seen those! I'm gonna keep the battery connected I think, shouldn't be a problem... Hopefully...

Can I ask what the 5HP18 means under your name????

[bubba966]

Lube the o-ring on the water pump with fresh un-diluted coolant when you install the new one. No need to use any other lube as anything else will contaminate the coolant.

[whiskychaser]

Hey Whiskey, always a pleasure!

I haven't seen those! I'm gonna keep the battery connected I think, shouldn't be a problem... Hopefully...

Can I ask what the 5HP18 means under your name????

Dont think leaving the battery connected should be a problem but those gizmos are handy just in case. Think the drain is a 17mm. I cant get at mine with a socket as the exhaust is in the way. I use a ring with another spanner looped through the the other end to get leverage. Watch your knuckles though!

5HP18 = ZF 5 speed auto box.