how best to install water pump and T-stat

[jkchappy]

I had someone build up a motor from a '71 Bavaria block and '81 528i head.

The new water pump is leaking, he didn't use a gasket when he assembled it.
My question: putting this back together should I use a gasket and some liquid gasket just liquid gasket or just paper gasket?

I also hope that putting the fan shroud in will stop the lower radiator hose from being hit by the fan.

I am trying to sort out this motor, I have a LOT in this and it is not yet running.

I need to get this running well enough to make a trip from St. Louis to Cleveland. I am hoping if it is put together properly it will be bullet proof.

I am replacing all coolant hoses and rubber fuel lines.

I have been having issues with it running rich but with coolant pouring out of it I have not been able to solve that issue. I am going to try a different AFM that I bought from a firstfiver.
let me know the best way to put this together please and thank you.

[Brian Smith]

I had someone build up a motor from a '71 Bavaria block and '81 528i head.

The new water pump is leaking, he didn't use a gasket when he assembled it.
My question: putting this back together should I use a gasket and some liquid gasket just liquid gasket or just paper gasket?

I also hope that putting the fan shroud in will stop the lower radiator hose from being hit by the fan.

I am trying to sort out this motor, I have a LOT in this and it is not yet running.

I need to get this running well enough to make a trip from St. Louis to Cleveland. I am hoping if it is put together properly it will be bullet proof.

I am replacing all coolant hoses and rubber fuel lines.

I have been having issues with it running rich but with coolant pouring out of it I have not been able to solve that issue. I am going to try a different AFM that I bought from a firstfiver.
let me know the best way to put this together please and thank you.

I've done 3 water pumps on M30s, and each time I used the gasket included with the water pump and various sealants between pump and gasket and gasket and motor. So far no leaks from any of those.

I think if your fan is hitting your radiator hose, the hose is probably not in the best place. If it only nicks the hose under high engine torque, worn motor mounts could contribute by flexing too far, but overall it sounds like the hose trying to be in the wrong place. I suppose the shroud would help if it pushed the hose away from where it's not supposed to be, but then the hose would be pushing the shroud toward where the shroud is not supposed to be... so while I'd rather have a damaged shroud on a long distance drive than a damaged lower hose, I think it would be more prudent to try to route the hose out of harm's way.

With my old Volvo 145, I was able to verify suspected worn motor mounts by using a wooden 2x4 about 6 feet long, cantilevered through the engine bay to the pavement between the motor and inner fender, then with both hands levering the motor up off the mounts. Perhaps if you did something like that on the driver's side of the car, you could see if motor motion that sends the fan into the hose is possible (do it with the engine off and an assistant pair of eyes, I would think.)

That's all I've got for now, good luck.

[T.Hanson]

Replacing (adding a gasket) to the water pump entails removing the fan, clutch, of which there are two types. The earlier type has a bolt through the center of the fan which requires removal of the radiator. If you know all that read on. If not, ask if you need to.

Haynes book likes goop on everything, seating ring and paper gasket. I've done three using gasket sealer only on the water pump/gasket side. This with new pumps, all parts clean. Theory being taking apart brings the gasket off the engine clean, no scraping in the bay off the hard to reach block.

No problems. 16 ft pounds torque, snug plus a quarter turn. Stat is aluminum, bolts go into steel block, tighten in x pattern all equal. Use anti-seize paste on all fasteners around coolant.

Install thermostat with outside strap vertical, use new style bolt head ( not slotted) bleeder screw w/anti-seize paste.

Lower radiator hose has a curve in the middle which takes some twisting, adjusting to clamp it so's it sits in there just right. Fan shroud was put there on purpose, not just to sell fan shrouds.

[alotawatts]

Lower radiator hose has a curve in the middle which takes some twisting, adjusting to clamp it so's it sits in there just right.

Good point.
Also I discovered that NAPA had mismatches/part numbers for the lower hose so be sure to buy from Pelican, AutoHausAZ, BavAuto, dealer etc.

[jkchappy]

New hoses are coming from Bavauto.

I have the radiator out, it is going to be boiled out and cleaned up.

I know about the center 13mm bolt holding on the fan and clutch.

I am considering replacing the motor mounts just because I can.

I am a fan of using gaskets, why else would some engineer put them there???
since the pump had goop only I have been cleaning the pump and block surfaces.

The next big question is use factory spec bolts or go to grade 8. The person who built this motor thinks that grade 8 is called for since he snapped 3 bolts putting the pump in and taking it out [ never mentioned the one he snapped putting it in ]

I want to get this back to where it wants to be, a good performing citizen of the BMW society. [ and fun to drive to boot ]

Thanks for all the replied

[Brian Smith]

The next big question is use factory spec bolts or go to grade 8. The person who built this motor thinks that grade 8 is called for since he snapped 3 bolts putting the pump in and taking it out [ never mentioned the one he snapped putting it in ]


Thanks for all the replied

Harder/stronger than stock bolts can also be less ductile/more brittle. They break when asked to bend to accept nonconformities.
With 6 or so M6 bolts, I think these are not being taxed near their limits even if lead was their material. I'd be more worried about corrosion, making them harder to subsequently remove, hence I'd choose stainless bolts if I were wanting an "upgrade." In fact, I did that for all but one of my bolts, and when I next had to replace the pump (3 years later) the only one that took a little concentration and effort to remove was the one that I didn't replace with stainless. I'll do that again the next time I replace a pump with stock bolts, but, you know, I'll get enough to do them all this time.

[jkchappy]

I was not in favor of "upgrading" to grade 8. My belief is that the engineers spec'd a bolt and that is what works in the motor. A water pump only takes 16lbs of torque, hardly a critical piece.

I am going to run a thread cleaning tap on the block side and make sure the metal is clean and free of goop. I am going back with the proper gasket and will do the bolts down to 16lbs.

I have sent the radiator out to be boiled out and pressure tested. They will fix any leaks found, though I doubt they will find any.

Sherman sold me a fan shroud I have brand new hoses coming, I will watch carefully when the bottom hose is fitted and insure that it is routed as far as it can be from the fan blade. I believe taking time and attending to details is going to make this a much happier Bimmer.

Once this is done I can move on to timing and rich running.

I love older cars.......

[Peter Florance]

In the cooling FAQ I mentioned that I planed my t stat cover flat. I think that goes a long way to preventing leaks.

Of course a new one would have been flat as well, but I'm much too cheap for that.

Agree on stock 8.8 bolts (metric grade 5-ish)

[jkchappy]

In the cooling FAQ I mentioned that I planed my t stat cover flat. I think that goes a long way to preventing leaks.

Of course a new one would have been flat as well, but I'm much too cheap for that.

Agree on stock 8.8 bolts (metric grade 5-ish)

I agree, if you do not take steps to make sure both surfaces are flat how then can you expect them to seal??? this is where the goop lovers say goop seals all....