M30 Coolant Pump Replacement

[Mitch90535im]

Getting ready to do a water pump replacement on my '90 M30. Any tips or advice?

Should I use some form of Permetex type sealant in addition to the gasket that came witht he new pump?

[anonymous1]

Getting ready to do a water pump replacement on my '90 M30. Any tips or advice?

Should I use some form of Permetex type sealant in addition to the gasket that came witht he new pump?

Hi,

Excellent write-up here. Think you should find all the information you need... http://www.bimmernut.com/forum/showt...ght=water+pump

Would recommend if you suspect the thermostat to be faulty to change this at the same time, save having to drain the system again.

HTH

[Rus]

No sealant is needed on the paper gasket. Its a little tricky to install since a lot of the time it comes all curled up in the pump box. I usually slide two of the mounting bolts into the pump and then hook the gasket on them. With a little patience, you can get the pump in pretty easily. Clean up the pump bolts so they don't corrode or damage the threads. Don't use a wrench to tighten the fan, just spin it on and it'll be a-ok.

+1 on the thermostat. Change it unless its new. Also, take a good look at the spigots on the t-stat housing. Mine got very crusty and nasty after nearly 19 years and my hoses started leaking at those connections. I ended up completely removing the thermostat housing from the block and cleaning the heck out of the spigots...no more leaks. Definitely something to look at if you're messing around in that area.

If you're not familiar with bleeding the M30 cooling system, you may run into minor issues. I normally drill a hole in the arrow stamping on the thermostat. Supposedly that helps get air out of the system. Bleed the car on a level surface or with the front slightly lower than the back. Fill the system with engine off and squeeze any hoses you can get your hands on to force air out of the bleed bolt on the t-stat housing and out through the reservoir on the firewall. Start the engine and keep squeezing those hoses once coolant starts circulating through the radiator. Keep an eye on the return line to the reservoir. There should be a steady stream of coolant pouring into the reservoir neck when there is no more air in the radiator.

HTH

[Mitch90535im]

"If you're not familiar with bleeding the M30 cooling system, you may run into minor issues."

Thanks Rus. That gets the prize for understatement of the year. I've had my e34 since 2001 so I've bled it (or attempted to) more times times than I care to remember.

Anyway, I noticed you recommended doing it nose down, whereas I've been doing it nose up. I might try nose down this time to see if it bleeds any better.

Knock on wood, but since 2001 the only unscheduled repairs I've done have been a radiator replacement, starter, and now the water pump. Not bad.

[Tiger]

Gasket sealant makes it easier to install water pump... you only put it on one side to the water pump. It merely helps the gasket stay on the waterpump until you start putting in the bolts.

[Mitch90535im]

Well, this one isn't going very well. Not one, but two water pump bolt heads rung off and a water water pump that will not release itself from one of the two remaining bolt shafts.

I've soaked it good with liquid wrench hoping to break the pump free tomorrow and then I'll soak the two remaining studs and try to remove them with a good pair of vise grips.

I wonder why my new pump came with only 3 new bolts instead of 6, because none of the 4 remaining intact bolts appear to be in very good condition.

Beginning to think I might have to take a chisel to the remaining threads around this frozen bolt to break the old pump housing away and expose the shaft of the bolt.

I'm kinda paranoid of damaging the block.

[e34.535i.sport]

I've soaked it good with liquid wrench hoping to break the pump free tomorrow and then I'll soak the two remaining studs and try to remove them with a good pair of vise grips.

A good tip for removing those studs: Get two nuts that will wind on to the stud and wind them on one after the other. Then use a spanner or whatever you can to back the 'first' nut off and the stud will come with it. Bish bash bosh...

Don't despair, we've all been there! You'll come out of it with a good sense of achievement!

If I were you I would replace hoses, thermo and waterpump all at the same time as it's just annoying when they start to go seperately. Trust me on that one Good luck, keep us informed!

[Mitch90535im]

Excellent tip (on using the two nuts), thanks.

[e34.535i.sport]

"Excellent tip on using the two nuts"

So many jokes in my mind right now...

[Rus]

"If you're not familiar with bleeding the M30 cooling system, you may run into minor issues."

Thanks Rus. That gets the prize for understatement of the year. I've had my e34 since 2001 so I've bled it (or attempted to) more times times than I care to remember.

Anyway, I noticed you recommended doing it nose down, whereas I've been doing it nose up. I might try nose down this time to see if it bleeds any better.

Knock on wood, but since 2001 the only unscheduled repairs I've done have been a radiator replacement, starter, and now the water pump. Not bad.

To be honest, I've never had that much trouble bleeding my M30. When I tried it in a nose-up position, the system wouldn't fill with coolant properly. More often than not, I bleed in as close to horizontal position as possible.

Sorry to hear about your bolt troubles. Those bolts always seem to get nice and rusty.