08 Z4 radiator fluid tank cap tight?

2008si · 12-11-2019, 03:19 PM

I checked fluids last night, found the cap hard as HECK to get off by hand. Had to use a towel and channel locks to break it loose. Should that not be just very hand tight and no more?

Our03z4 · 12-11-2019, 04:22 PM

I keep mine snug hand tight. How many miles on the car? If it hasn't been done yet go ahead and replace that tank and all the bits that go with. If it's an automatic also replace the transmission thermostat, it's below that tank and is a commonly missed part that has to be replaced. Those tanks are a ticking time bomb and can burst with no warning. Happened on both of my z4s. Same with the electric water pump.

Steeler · 12-11-2019, 06:19 PM

The cap on my rad is hard to rotate as well. Plastic on plastic is not the slipperiest surface. I smeared a bit of lithium grease on the cap threads which made it a little easier to rotate

2008si · 12-11-2019, 07:58 PM

57k

Quote:

Originally Posted by Our03z4

I keep mine snug hand tight. How many miles on the car? If it hasn't been done yet go ahead and replace that tank and all the bits that go with. If it's an automatic also replace the transmission thermostat, it's below that tank and is a commonly missed part that has to be replaced. Those tanks are a ticking time bomb and can burst with no warning. Happened on both of my z4s. Same with the electric water pump.

Our03z4 · 12-11-2019, 08:27 PM

Quote:

Originally Posted by 2008si

57k

Not too many miles but I would still do it with it's age. Mine had 89k and blew, the other had around 100k. That plastic gets brittle and is under pressure of course.

12-11-2019, 03:19 PM	#1
2008si Enlisted Member 5 Rep 34 Posts Drives: 2008 Z4 Join Date: Nov 2019 Location: SW OHIO iTrader: (0)	08 Z4 radiator fluid tank cap tight? I checked fluids last night, found the cap hard as HECK to get off by hand. Had to use a towel and channel locks to break it loose. Should that not be just very hand tight and no more?
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12-11-2019, 04:22 PM	#2
Our03z4 Captain 1690 Rep 685 Posts Drives: 2008 BMW Z4 3.0si Coupe, Join Date: Nov 2016 Location: USA iTrader: (0)	I keep mine snug hand tight. How many miles on the car? If it hasn't been done yet go ahead and replace that tank and all the bits that go with. If it's an automatic also replace the transmission thermostat, it's below that tank and is a commonly missed part that has to be replaced. Those tanks are a ticking time bomb and can burst with no warning. Happened on both of my z4s. Same with the electric water pump.
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12-11-2019, 06:19 PM	#3
Steeler Colonel 2428 Rep 2,704 Posts Drives: Built not Bought 04 Z4 VF Join Date: Feb 2013 Location: Kitchener Ontario Canada iTrader: (2)	The cap on my rad is hard to rotate as well. Plastic on plastic is not the slipperiest surface. I smeared a bit of lithium grease on the cap threads which made it a little easier to rotate __________________ W2A Intercooled Vortech V3Si, custom ducting, Alpha N, 60# Bosch,2.62 pulley, multi port WMI, Severn Tuning(pokeybritches), Tial, magnaflow,SS race muffler, 42 design,3.91LSD, H&R, Hotchkis,ST coils,Konis, Megan camber arms, AKG SS, Nylon mounts, Poly bushings, Carbon interior, CF Aero.APEX
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