How do I tell if water pump is bad?

[Yellow_rag]

hey, just bought an 03 Cobra a couple weeks ago. 2 days ago overheated. I know the guy I bought it from burped it properly btw. Anyway, let it cool overnight and fire up in the morning. Crossover gets hot, upper radiator too how to touch, pass side of rad warm, driver side cold, thermostat housing cold.

If thermostat housing is not heating up does that confirm water pump is bad? It doesnt appear to be leaking btw. Is only way to confirm water pump to remove thermostat and see it that fixes it? thanks for the help, I searched the forums but couldnt find this exact question answered.

 

[Yellow_rag]

Bueller?

 

[WhiTriCobra]

Easiest/cheapest would be to change out the thermostat first, refill on cross over tube by SC, burp the system and see how she runs. Usually if the waterpump is bad, the weep hole would be leaking but you never know. I know i've drained my coolant a few times and it takes a good process to get all the air bubbles out. Try it on jack stands and make sure you have the heater on full blast.

 

[wjurls]

Does the heater work? If so it's probably not your water pump. If your pump is bad it will overheat super fast. Even faster then with a stuck closed thermostat. I agree with the above post. Start with a new stat and go from there.

 

[Yellow_rag]

thanks for feedback. I suppose changing thermostat is surest way to tell. I'll check heater when I get home tonight - good idea, should have thought of that. Btw, it did heat up to hissing point after idling <10minutes.

What I keep thinking about is that thermostat housing being cold. There has to be some bypass activity to activate opening so it should have at least been warm with the crossover being so hot I couldnt touch it.

Waterpump looks like a motha to change. Anybody know if the PW464 is correct Motorcraft waterpump PN? thanks,

 

[Yellow_rag]

For the inquiring minds out there, I fired up car last night with heater on, starting blowing hot air in 5 min. So appears waterpump is pumping, which is definitely a good thing. I'll order Reisch thermostat but I'd really like to understand why the housing never gets warm. Makes no sense - how can thermostat ever open if hot water not getting to it to activate it? Not like old car with thermostat sitting right on intake manifold.

Anybody got experience with Mishimoto 3 core radiator? Stock rad or whatever I got in there now seems very thin, like a 1 core. thanks,

 

[mu22stang]

The coolant burp process is somewhat involved on 4V modular engines. Follow the burping procedure on Reische's site VERBATIM and you should be golden.

Now, a couple of my pennies...

Do not waste your time or hard earned cash on an "upgraded" radiator. They add weight exactly where you don't want to add weight, don't necessarily cool any better, and often leak. The first step to making your Terminator run cooler is to cut the flaps on underside of the hood heat extractor vents. Then, check your temps post Reische t-stat install. If you need to run cooler, adjust your fan settings. If you still need to run cooler, box your radiator and heat exchanger. If you still need to run cooler, increase the depth of your air dam.

All those combined will cost less, and perform better, than an aftermarket radiator.

 

[Yellow_rag]

hey, thanks for input. Looks like flaps on vents already removed. I just got an SCT S3 so will be turning down the fan points too. Looks like the radiator is bad, I see some steam near the edge - cant tell if its in the aluminum or the tank though. Regardless I thought I'd get another rather than have an old one repaired.

Any input to what kind of radiator is best? Mishimoto was much cheaper than Motorcraft, has 3 rows too. thanks