Hey fellas,
I finally took the plunge and got my dream car, 2000 z3 m roadster. I remember loving it while playing need for speed on the original play station as a child and it’s always caught my eye on the streets. Mine was 250 miles from my house in Jupiter Florida well taken care of in a garage by an older man and I enjoyed every second of the drive home up until it started getting a cooling issue. I drove home most of the way doing 70mph on the highway at 3k rpm and trouble free. I live in Key West and once I hit the keys traffic slowed considerably and I noticed the temp gauge was awfully close to the red when I stopped to get fuel. I’ve been trouble shooting it since then and I’ve gathered that at higher than 2.8k rpm the gauge drops back to 12 o’clock and if I ease off in slow traffic or at idle it will start inching towards the red. I’ve done some reading around in the forums and it appears to be a faulty water pump because the receipts state everything else in the cooling system was replaced around 40k miles ago with exception of that item and these are known to fail.
There is a very small coolant leak coming from the thermostat housing at high temps and I was planning on remedying all of that when I replace the water pump so I’ve purchased a thermostat and housing as well.
Can you guys offer me any advice or point me to a good thread with pictures where someone has done this before, I am going to buy the specialty tools to take the fan off because my 32 mm wrench is too thick to get onto the fan nut and I plan on working on the car in the future.
Thank you
This may help -
Go to https://www.pelicanparts.com/More_In...SVSVSI=633.htm
Then click on the "Tech Articles" tab.
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, Black Soft Top, Steel Gray Metailic Hard Top, TC Kline Double Adj Shocks with H&R Springs, Stromung Exhaust, SSR Type C Wheels. Looking for a new home.
2022 Z4 M40i, Misano Blue Metallic, Prem Pkg, Driver Assistance Pkg
2023 X5 M50, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
That leak could explain it all. If it was cooling at 70 mph, it's not the water pump. When you go in to fix the Tstat leak, you are right to replace the water pump also, because you don't know how old it is. (Who would replace most of the cooling system without replacing the water pump?) Put Go5 in it. Burping the system after taking it apart is very important. Fair warning: unless you can verify it's been done, replace heater hoses. Most people skip them because they are way back there and so little, how could they cause a problem? (ask me how I know that they can)
Considering that you are in Florida, another possibilty could be the auxiliary fan if you were using the ac at the time. If the fan isn't working correctly, it could overheat the engine very quickly in heavy traffic.
2000 Z3 M Titanium Silver / Imola Red+Black Nappa
2011 328i E92 Space Gray Metallic / Leder Dakota+Oyster
Since 1987 12 euros / 2 kdms / 2 jdms
- Zach
So was the radiator replaced as part of that overhaul 40K miles ago? If not that would be good to do as well, but I agree with Zellamay--if there is a leak, there is air in the system. Of course you must confirm the aux fan is working. Also, was the viscous fan clutch replaced at that time (and the fan blade)?
Radiator was replaced it’s the aluminum one now. Aux fan turns on, I confirmed this when I turned on the ignition. Also mechanical fan seems to pull strong. I was able to slow it down and stop it with a flimsy piece of plastic but it wasn’t easy to stop. It’s a black plastic fan so I am going to check the manufacture date and consider replacing it due to the stories I’ve read of them self destructing and causing costly repairs. Going to burp the system once I get the water pump in and hopefully all this can be cleared up. also will check the heater hoses once I figure out where they are. There’s an auto hobby shop very close to me with a lift that charges $5 an hour so I can get a lot of this stuff knocked out on my free time. Very excited to finally be excited to work on a vehicle I own.
Thanks for all the quick replies I was pleasantly surprised, and very appreciative. Going to have a look at the link now.
Changing the water pump: https://www.newtis.info/tisv2/a/en/e...-drive/BBvduBI
You may want to consider buying the Bentley Service Manual for the Z3. It doesn't cover everything, but it is fairly complete.
Test the fan clutch along with the auxiliary fan.
99 M Coupe
99 996 Cabrio
86 Saleen Griggs Road Race Car
A water pump failure is quick and obvious; not your problem. I think the leak is your problem. You have not said what your coolant level was when cold. Low coolant means air in the cylinder head means the needle moves toward red. Reaching and staying in red for a few minutes can mean a warped head and compromised head gasket. Fix the leak.
Except for AC, I wonder how important a fan is. My car only has one fan, electric, and it never comes on except when fully stopped for minutes in hot summer traffic. (It does come on Low anytime the AC is on, which I never use because top down all summer.)
Last edited by Vintage42; 02-13-2019 at 03:41 PM.
BMW MOA 696, BMW CCA 1405
Sometimes the water pump warns you before it actually fails, by seeping water out of that little hole in the bottom.
A friend of mine had a water pump failure (as it turns out) which was thought to be a thermostat issue. He was able to drive it home, at highway speeds, keeping an eye on the temperature, which never got much over the normal operating level. When we dug into it to replace the thermostat we found that the water pump impellers had self destructed. So not all water pump failures are the same or display the same symptoms.
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, Black Soft Top, Steel Gray Metailic Hard Top, TC Kline Double Adj Shocks with H&R Springs, Stromung Exhaust, SSR Type C Wheels. Looking for a new home.
2022 Z4 M40i, Misano Blue Metallic, Prem Pkg, Driver Assistance Pkg
2023 X5 M50, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
For the record, what water pump? There is talk about whether we need the metal blades, and the diffs among them. Also, that is scary info, because that means the water was not circulating, which means the temp gage was only telling you the temp at the front of the engine.
This, very much this. I've seen plastic impellers spun off, metal impellers with sheared blades.
It's not a question of type, plastic stamped or cat. It;s the quality. The factory used both. As far as failures go, this is one of the safest, if the hardest to diagnose. As I've said many times, as long as there is LIQUID coolant in the head, you are safe. Also, the temp sensor is not in the front, or the back. It is in the internal pipe routing coolant out of the engine on some models, into the engine on others.
OP. You had/have the symptoms of an airlock in the head. A large one. Another symptom would be your oil temp should have been through the roof. 250-260. When airlocked (or the cooling system is overwhelmed) the oil running down from the valvetrain becomes the primary coolant.
One other thing I've said too many time here. Testing a fan by sticking something into it is stupid. First, because sticking something into rotating machinery is flat out dumb. Second, you can't tell anything more than if it's totally locked up or not. You have no idea what the sensor temp is or the point on the viscous curve things are. Engine temp is not a factor.
Quit messing with the fans, and the waterpump. Your issue is an airlock caused by the leaking t/stat. The expansion tank is empty by siphon. Thus the level is no indicator when there is an air leak high in the system.
/.randy
This was the stock water pump on an S54. We guessed that even with most of the mass of the impellers no longer working, there was still enough material on the shaft that there was some water movement. It was also a cool day and there has been no adverse issues after the new pump was installed. The incident happened several months ago and he daily drives his M Roadster.
2002 M Roadster, Steel Gray Metailic, Gray Nappa Leather, Black Soft Top, Steel Gray Metailic Hard Top, TC Kline Double Adj Shocks with H&R Springs, Stromung Exhaust, SSR Type C Wheels. Looking for a new home.
2022 Z4 M40i, Misano Blue Metallic, Prem Pkg, Driver Assistance Pkg
2023 X5 M50, Phytonic Blue, Black Extended Merion Leather, Driving Asst Pro Pkg, Park Asst Pkg, Exec Pkg, Climate Comfort Pkg.
Just want to go on record here to let everyone know rf900rkw or Randy was right I had an air lock. Thank you for the very good advice on the correction and not sticking things in the fan I felt pretty ashamed about it and won’t be doing it again haha. That being said I am still getting the water pump and thermostat and will keep them handy for if I should need them in the near future.
Thanks again to all of you guys.
BMW MOA 696, BMW CCA 1405
The airlock was caused by the low coolant level and the thermostat housing leak is yet to be fixed I have the fan tools on the way. I was just anxious to diagnose the overheating so I went ahead and bled the system to see if that was the cause and it cleared right up. I didn’t think there would be air in the system because the coolant reservoir wasn’t empty guess I’ve got a lot to learn.
I’ll be pulling the housing and putting some rtv in there tomorrow hopefully.
I suggest you don't do that; that you get a new Tstat, with proper gasket, and install properly. You can choose whether to replace the water pump while in there. I'm facing a bad Tstat on my wife's 325i, (engine won't come up to temp in cold weather), and I will put in a new water pump because I have no idea how old it is.
Zella I did some reading about your overheating issues that looked similar to mine, guess I might as well replace it all while I’m in there. I’d hate to have it overheat big time when I’ve let my guard down. Going to be replacing my oil temp gauge and a couple other items as well. A bunch of little problems like the dash bulbs and gauges on the center console need replacing I can’t see anything at night
I left my clutch fan out after my last repair. Granted it is winter, but no issues yet. I almost never heard it spool up, and when it did it was only for a few seconds after idling.
Do you know if the thermostat is cracked or just a faulty gasket?
When removing my fan the wrench leaned up against the thermostat housing and cracked it. I glued it up with some permatex 84145 and so far so good.
I figured I would hear that.
Many users on this forum are older guys with a little bit of change to spare. This is my first car. I got it when I was 17, now 21. I'm a junior in college, and my parts come out of my student loans. So.... no.
If it makes you feel any better, instead of replacing the whole serpentine belt tensioner when the bearing died, I just pressed the bearing out and pressed a new one in. Then I broke it in the process. Then I took my old ac pulley, pressed the bearing out, machined a sleeve, and pressed the bearing into that. >
I like to consider myself a mechanic and not just a parts swapper. This isn't the first part I have modified or built from scratch and it won't be the last.
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