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Re: While You're In There: Coolant Expansion Tank
Posted: Mon Mar 12, 2018 10:37 am
by 5chn3ll
Composite - reason being that St. Raby claims the metal impeller, once the bearing gets wonky, will start to machine away at the block and send bits of metal throughout the cooling system.
Apparently, this is worse than sending bits of composite impeller throughout the cooling system.
The sanity check for your water pump: remove the belt and ensure:
A) The pump spins freely. It won't freewheel, but it should turn with very little effort.
B) Wiggle the water pump pulley. If there is ANY side-to-side play, replace it.
C) Examine the underside of the water pump for evidence of dried coolant. Look around the engine bay for evidence of cast-off coolant. If the pump is leaking where the shaft exits the pump body, replace it.
I try to remember to do this with every oil change. Once the bearing starts to fail and the impeller shaft is able to deviate from being perpendicular to the mating surface, it's time to swap out the pump.
Re: While You're In There: Coolant Expansion Tank
Posted: Mon Mar 12, 2018 5:31 pm
by 32wildbilly
I thought the really bad thing about the metal impeller was when the bearing starts to fail the metal will contact the cavity machined in the block and render the EXPENSIVE block into a boat anchor.
Here's what I want to know...Why is the M96 water pump so incredibly fragile? I've driven/owned cars for over 50 years and can only remember changing four water pumps: Sunbeam Tiger, Ford Ranchero, Nissan 300zx and the 911(because it puked water everywhere and made squeaking noises). Never have I done a timed/mileage change out of a water pump in those 50+ years! Just what the F is that all about?
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 5:43 am
by B3DAWG
32wildbilly wrote: ↑Mon Mar 12, 2018 5:31 pm
I thought the really bad thing about the metal impeller was when the bearing starts to fail the metal will contact the cavity machined in the block and render the EXPENSIVE block into a boat anchor.
Here's what I want to know...Why is the M96 water pump so incredibly fragile? I've driven/owned cars for over 50 years and can only remember changing four water pumps: Sunbeam Tiger, Ford Ranchero, Nissan 300zx and the 911(because it puked water everywhere and made squeaking noises). Never have I done a timed/mileage change out of a water pump in those 50+ years! Just what the F is that all about?
Amen to that Billy! I wondered the same thing. What in the world is with German sourced plastic composite parts? If it's not the chain guides, it's the water pump impeller breakin' up, or the Becker radio knobs going to goo.... Lawd help us! And, why in the heck did they paint many of the plastic parts on the interior? Don't they know that molded colored plastic is much more durable than painting the plastic with some rubberized "soft-touch" paint? I recently tried to change two of the so called parking light bulbs inside the expensive Hella front light enclosures. The darn plastic bulb fixture crumbled in my hands. German plastic apparently doesn't age well.
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 6:41 am
by 32wildbilly
I believe it is a function of the accountants setting the standards based only on cost.
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 8:45 am
by 5chn3ll
...and the whole "Well, it was the first water-cooled 911; they didn't know what they were doing" thing is BULLSHIT. Porsche made PLENTY of water-cooled cars before the 996 came along.
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 10:30 am
by 32wildbilly
Seems Porsche has a lot of bearing problems!!?? Is it an undersize deal or a side load problem. I'm no engineer so I'm spitballing here.
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 4:23 pm
by wyovino
It's not a matter of the water pump being fragile (fra-gee-lee), it's a matter of the damage it can do if it fails. From my understanding, the tolerances are so tight that if you get enough wiggle from the bearing, the impeller can contact metal and shred off some plastic bits and potentially cause major problems. I changed mine out at 16 years/60k miles and it seemed fine. There was a very slight noise when spun by hand after removal. The new one was completely silent.
Back to the original post. I will be preemptively swapping out my old coolant tank even though there are currently no issues. It looks yellow and it is 18 years old, so might as well. I'm adding the updated cap even though the original never leaked. I will also swap out the break-prone plastic hose connector for a beefed-up aluminum version -
https://www.ebsracing.com/product/conne ... 84-c722102
After reading way too much about coolant I decided on Zerex G-40 coolant for topping off.
I'm thinking about replacing the motor mounts at the same time. The car only has 65k but I figure that gravity has some say in the matter.
Unrelated except that I'll have my tools out and my hands will be dirty, I'll flush the brake fluid (ATE 200 DOT 4) and do an oil change.
Of course this all depends on winter coming to an end which kind of looks doubtful at the moment.
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 4:37 pm
by B3DAWG
wyovino wrote: ↑Tue Mar 13, 2018 4:23 pm
It's not a matter of the water pump being fragile (fra-gee-lee), it's a matter of the damage it can do if it fails. From my understanding, the tolerances are so tight that if you get enough wiggle from the bearing, the impeller can contact metal and shred off some plastic bits and potentially cause major problems. I changed mine out at 16 years/60k miles and it seemed fine. There was a very slight noise when spun by hand after removal. The new one was completely silent.
Back to the original post. I will be preemptively swapping out my old coolant tank even though there are currently no issues. It looks yellow and it is 18 years old, so might as well. I'm adding the updated cap even though the original never leaked. I will also swap out the break-prone plastic hose connector for a beefed-up aluminum version -
https://www.ebsracing.com/product/conne ... 84-c722102
After reading way too much about coolant I decided on Zerex G-40 coolant for topping off.
I'm thinking about replacing the motor mounts at the same time. The car only has 65k but I figure that gravity has some say in the matter.
Unrelated except that I'll have my tools out and my hands will be dirty, I'll flush the brake fluid (ATE 200 DOT 4) and do an oil change.
Of course this all depends on winter coming to an end which kind of looks doubtful at the moment.
Welcome to the Outpost man! Make yourself at home. And, after reading your post, I wanna run out and lay hands on my car in prayer.
You sceeerd me man!
Re: While You're In There: Coolant Expansion Tank
Posted: Tue Mar 13, 2018 5:14 pm
by wyovino
Just swap out your engine every 5k miles and you'll be fine.
Re: While You're In There: Coolant Expansion Tank
Posted: Wed Mar 14, 2018 4:48 pm
by sweet victory
Since I'm coming up on 6 years since the water pump has been changed, I'm probably just going to replace it. So far my my current list of crap to do:
- Waterpump (Composite Impeller)
- Thermostat (Not low temp)
- Various Coolant Hoses (Part numbers to come later)
- Coolant Expansion Tank
- Coolant Tank Cap
- Coolant Flush (Replace with OEM lifetime coolant)
Then hopefully not worry about shit for a while. I'll try to make a detailed guide to help get more documented technical content on this forum. I appreciate everyone's input so far!
