E36 water pump identification

On an E36 320i (105K miles), is it possible to check if the water pump has the original plastic impeller or been replaced with one with a metal impeller - without dismantling anything?

I can't see any obvious difference from the pictures at

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as it's on the last dashboard light before the next service, I thought I may as well get it replaced at the service if it's plastic. Andrew

Reply to
Andrew Morton
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No. You'll have to pull it off to tell. If you bother doing that you might as well put the new one in, especially if yours is of unknown mileage. Peace of mind is worth more than the price of a waterpump, IMO.

Reply to
Fred W

Thanks; I'll ask the local BMW specialist how much they'll charge (UK).

Andrew

Reply to
Andrew Morton

When did they stop putting in the plastic impeller?

Reply to
SQ

1996?
Reply to
John Burns

Pump is 25 quid from Euro Car Parts. Good plan to change the thermostat at the same time (6 quid). Allow an hours labour or less.

Reply to
John Burns

BMW now only supply a "new improved" plastic version. I was plenty surprised last November (and pretty skeptical) when I opened the box at the BMW dealers to find a plastic impeller on the new part! The faulty one I was replacing was a metal type which had failed due to the bearing collapsing (This pump was a replacement genuine part from 1997). Mind you, this M50 lump in my old E34 had only had the original plastic impeller (dodgy type) pump amd one metal replacment in 341,000miles when I fitted the 'new' plastic type last year.

JB

Reply to
JB

so would a '97 E36 be safe from this?

Reply to
SQ

No E36 is safe. Waterpumps and radiators are maintenance items for these cars, change every 75K miles. If you want a PREMIUM pump,, Stewart is making a performance water pump for the E36. About $200 from several online vendors. It's capable of higher flow and improved efficiency.

The upper plastic inlet on the radiator fails with age. Sometimes it just breaks right off, leading to a loss of coolant accident, overheating, and the resulting head warpage.

Even with stock parts, it's less than $250

Reply to
Richard Sperry

Yes, but the best replacement is an all aluminum aftermarket one made by "Dynaflow"? or some such outfit.

Reply to
Fred W

I agree. Reason I'm writing is that I just had a major cooling system overhaul done on my 1998 E36 at 130K miles so this is still fresh in my mind.

Based on my technician's comments (30+ years of experience) the only reason the radiator necks break is because they've been overheated -- usually repeatedly -- by running the coolant level too low.

Of course, overheating can also be caused by a catastrophic pump failure when the driver decides that "it should be okay" to drive a couple more miles to the nearest gas station. And that's the absolute worst thing you can do. If you hate the cost associated with a water pump replacement, you'll really hate the cost of fixing a warped head. Rule of thumb for BMWs -- if the temperature needle starts climbing toward the red zone, pull the hell over NOW, turn off the car and call a tow truck. Your checkbook will thank you.

The usual sign that the radiator is not long for the world is oval (warped) necks...and possibly associated leaks, but as I found out, simple wear and tear may not show up from the outside, which explains why it's indeed a good idea to replace the radiator on some regular interval. My tech found the plastic crumbling on the inside of the necks, while the exterior looked like new. The necks could have broken at any time.

If you follow BMW's guidelines on coolant flushes like I have, my car is at least anecdotal evidence that the OEM components will last a very long time. Based on my experience, I'd suggest 100K as a safe and fiscally prudent time to do a pump replacement, but the funny thing about touching the cooling system is that it usually makes a lot of sense to replace everything else while you're in there (radiator, thermostat/housing, hoses, belts, etc.) Parts cost more, but the labor savings more than makes up for that.

Check out my site for more info including a close-up picture of the currently-shipping composite impeller pumps. Click through:

BMW->E36->Maintenance->2006->May

Safe driving,

-Doug

-------------------- Doug Vetter, ATP/CFI snipped-for-privacy@yahoo.com

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Reply to
Doug Vetter

Best? Best for what? There are OE or OEM replacement radiators, Baer,and some others. All will work, most if not all will have plastic side tanks and hose fittings. FluidDyne, PWR, Zionsville, and others sell custom all aluminum replacements, some with 3 cooling rows. All of these will work, there have been some fitment issues with some of these. There is also the radiator from the MZ4 roadster that is a direct fit replacement. With a cost of $150 to $750 How do you decide which is best?

Reply to
Richard Sperry

FluidDyne is what I was thinking of. I beleive they make the one sold by Zionsville too. Haven't heard of PWR before.

What I meant was that that the fully aluminum replacement by FluidDyne was best if you are concerned about the logevity of the radiator. It does not have plastic ends or hose fittings. Yes it costs more.

Reply to
Fred W

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