How can you tell if your water pump is not working?
Thread Starter
Senior Member
Joined: May 2004
Posts: 432
Likes: 7
From: Albuquerque, NM
09' E350, 01' Maxima SE, 93 Nissan Maxima SE, 1987 Nissan Maxima SE
How can you tell if your water pump is not working?
I've been wondering about water pump going bad. What are signs of the pump going bad or failed? Cuz it got me wondering since the cold weather is already here. I've noticed how long it takes to warm the car up and the temp gauge hasn't moved to the middle, not even 1/4 mark, til I start driving it for 30 miles then it moves up to a bit past the 1/4 mark. Is this normal. Post yours how long does it takes for the temp to move half way. Just to remind for those who post, it's applies to the Inline-6 engine
MBWorld Fanatic!
Joined: Nov 2001
Posts: 4,260
Likes: 6
From: Philadelphia area
2010 ML550, 2010 E350 4M, 1966 Corvette Convt C2
Bad water pump would overheat the engine rapidly. What you are experiencing is most likely a thermostat stuck open. Get it replaced before you damage the engine
Super Member
Joined: Sep 2003
Posts: 783
Likes: 1
From: Murrieta, Southern California
Late Built 2005 W-211 E-320 CDI
Bad thermostat for sure!
As sosh has said above, you do have a malfunctioning thermostat that is not closing at all. :v
When they fail, they're designed to fail open.
One can only imagine what would happen if one were to fail in the closed position!
When you first start it up cold, your car should reach normal operating temperatures within just a couple of miles. Normal being where it used to show on the gauge when the thermostat was functioning properly.
I wouldn't wait until you plan on changing your coolant later, but do it now.
You're not helping your engine at all driving it around cold all the time!
Remember, the majority of any engines' wear occurs when the motor is cold.
Aren't you experiencing poor heater operation also?
Last edited by Green E-300 DT; Dec 4, 2004 at 11:39 AM.
Thread Starter
Senior Member
Joined: May 2004
Posts: 432
Likes: 7
From: Albuquerque, NM
09' E350, 01' Maxima SE, 93 Nissan Maxima SE, 1987 Nissan Maxima SE
In fact, i just noticed my heater wasn't getting warm at all, that made me wonder since the cold weather is already here. It's like 27 degree in Albuquerque, frigid cold. BRRRRH. So yeah, that's why I was questioning whether if my water pump is not working or was the Coolant needs to be change where it's not effective. Cuz when I acquired the car about nine months ago, I couldn't determine if the coolant has been changed since I looked and MB said their coolant is not green.
Super Member
Joined: Sep 2003
Posts: 783
Likes: 1
From: Murrieta, Southern California
Late Built 2005 W-211 E-320 CDI
See?
There you go; Proof that the coolant is not warming up enough.
Don't know exactly for your car, but most modern cars run somewhere between 180 degrees and 205 degree thermostats.
When your thermostat is stuck open, the coolant doesn't stay in the block long enough to be warmed up properly, and therefore you've got no or very little heat from your heater.
Not only that, but your computer is reading those "cold" engine temperatures,
and may be ordering up a slightly richer fuel mixture.
What kind of fuel economy are you getting?
All in all, it isn't good for you or your motor.
Get that coolant changed and replace that failed thermostat with a new one pronto.
