Re: How did you know the coolant temp hit 210F? BTW, that's not hot, not by a bit...

Looking for what to do next! My 99 Boxster with @120k miles chewed up a water pump about 2 years ago. The last week it started pushing 210 degrees so turned off and let her cool down. After cooling I drove the three miles home.... it went to about 210 again. So I decided to remove and inspect the water pump and thermostat. Both seem to look in fine condition. The pump turned freely and the fan blades all looked undamaged. Now I don't know much about thermostats... but I believe they can look fine but not opening at the right temp. So I was planning to purchase a new thermo and try reassembly and crossing my fingers. Not sure what other avenues to check... should I remove the nose clip and check the radiator? Could the fact that my heater fails to put out good heat be any kind of an indicator. I'm hoping someone might steer me in the right direction. Y'all have been a great help in the past! Thank you! David in Charleston, SC.

... check the cooling fans up front.
Turn on the A/C and make sure that each side is working on high.
If not you may have blown the ballast resistor or the fan itself.
You can check the thermostat by putting it in a cooking pot submerged in water.
Put a thermometer that can measure up to 212F and set it on the stove.
Check the temp when the thermostat pops.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Thanks ? When a Box overheats where is the overflow? also if you're fan has died would the car cool down after certain amount of speed? I drove home at about 60 and the temp did not go down.

wouldn't that indicate that the coolant isn't heating up enough? (I know the temp gauge is indicating otherwise)

Could it be a faulty temp sending unit or gauge?

Could also be dirty radiators, they tend to get clogged with all kinds of road debris.

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SilverBox99
Looking for what to do next! My 99 Boxster with @120k miles chewed up a water pump about 2 years ago. The last week it started pushing 210 degrees so turned off and let her cool down. After cooling I drove the three miles home.... it went to about 210 again. So I decided to remove and inspect the water pump and thermostat. Both seem to look in fine condition. The pump turned freely and the fan blades all looked undamaged. Now I don't know much about thermostats... but I believe they can look fine but not opening at the right temp. So I was planning to purchase a new thermo and try reassembly and crossing my fingers. Not sure what other avenues to check... should I remove the nose clip and check the radiator? Could the fact that my heater fails to put out good heat be any kind of an indicator. I'm hoping someone might steer me in the right direction. Y'all have been a great help in the past! Thank you! David in Charleston, SC.

My info is the fans do not even come on low speed until the coolant temp hits 212F and they shut off at 205F. The only switch to high if the coolant temp hits 216F.

Also, after exposure to high ambient heat in my 02 Boxster which resulted in a steady coolant temp of 226F being concerned by the high coolant temp I checked with my SM and he checked with the factory and the word back from the factory was no if there was no warning light, steady or flashing there was no overheating condition.

If you removed the water pump whether you reuse it or replace it be sure you use a new gasket.

Ditto the t-stat.

In the future no need remove the water pump to check it.

With the belt removed check it for any play. You have the other accessory drives for comparison. Any play at the water pump pulley/shaft, any signs the belt's rubbing -- one or both edges will be "sharp" -- is a pretty good sign the water pump is on its way out.

Another check is to get the engine nice and hot then raise the idle until the radiator fans some on. Shut off the engine. Still under the car -- but very very mindful things are very *hot* and there's the risk of a cooling system leak of getting sprayed/doused with scalding hot coolant -- observe the water pump for any signs of coolant oozing out.

You can test the t-stat by with the engine running at idle and from under the car confirming -- being very careful to avoid getting any clothing/body parts in the serpentine belt! -- the coolant hoses from the water pump to the radiators get hot. This is a sign the t-stat is opening when the coolant gets hot enough.

If you want to test the t-stat on the bench -- so to speak -- drop it in a pan of hot water on the stove and raise the water's temp -- using a digital cooking thermometer -- to verify the t-stat opens at its stated temp and as the temp of the water increases the t-stat is fully open.

Now that you have opened the cooling system you have to after you it all buttoned up again refill the cooling system with the right amount of the right anti-freeze mixed with distilled water and avoiding any water pockets.

My choice would be getting a setup that pulls a vacuum on the cooling system and then allows you to close the vacuum line and open a line to the reservoir of coolant which is open to atmosphere which will push the coolant into the cooling system with no air pockets.

Sincerely,

MarcW.

See here for more info:

[www.ppbb.com]

and OBD2 code reader/data viewer and noting at what coolant temp the fans come on and go off and 212F is the trigger for low speed, 216F is the trigger for high speed, and 205F is the shut off point. I do not recall the details but the A/C can trigger the fans to switch to high speed operation.

Sincerely,

MarcW.

I have a question after seeing Pedro's comment above:"Turn on the A/C and make sure that each side is working on high." I tried this but only the right front fan comes on. Does this mean I have a problem with the left front fan? If one fan comes on should they both be on? I have never paid much attention to whether the radiator fans were working or not. I have heard them/it run but never noticed if it was left or right or both. The temp gauge, once engine is warmed up, has never moved off 175. Car is a 2007 "s" with approx. 18,000 miles bought new. Any thoughts would be appreciated.

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oldhoo07s
I have a question after seeing Pedro's comment above:"Turn on the A/C and make sure that each side is working on high." I tried this but only the right front fan comes on. Does this mean I have a problem with the left front fan? If one fan comes on should they both be on? I have never paid much attention to whether the radiator fans were working or not. I have heard them/it run but never noticed if it was left or right or both. The temp gauge, once engine is warmed up, has never moved off 175. Car is a 2007 "s" with approx. 18,000 miles bought new. Any thoughts would be appreciated.

Both front fans should come on at the same time.

You likely have not heard the radiator fans from inside the car. The fan you can hear while in the car is the engine compartment fan that draws hot air out of the engine compartment through the right (passenger side) side vent.

Guenter
2014 Boxster S
GT Silver, 6 Speed Manual, Bi-Xenons, Sports Suspension (lowers car 20mm), Porsche Sports Exhaust, Porsche Torque Vectoring, Auto Climate control, heated and vented seats, 20" Carrera S Wheels, Pedro's TechNoWind, Sport Design steering wheel, Roll bars in GT Silver
[www.cyberdesignconcepts.com]

In checking the front radiator fans, I actually got out of the car with the engine running at operating temperature with A/C on high and went to each radiator in front. I could feel the air and hear the noise from the right radiator fan. There was no noise and no wind from the left side fan. Does this indicate a problem with the left fan? Is there a separate fuse for this fan?

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oldhoo07s
In checking the front radiator fans, I actually got out of the car with the engine running at operating temperature with A/C on high and went to each radiator in front. I could feel the air and hear the noise from the right radiator fan. There was no noise and no wind from the left side fan. Does this indicate a problem with the left fan? Is there a separate fuse for this fan?

As per Pedro's post above (see First), it sounds like you may have blown the ballast resistor or the fan itself.

Sure, 210 isn't real hot... but the norm is around 180 and didn't want to see the temp go any higher. Sure didn't want to hurt the engine. It was past the normal 180 a little over the next tick mark... there isn't a number but I estimated it to be around 210.

I did boil my thermostat until it opened. It was around 185 when I could see it actually crack open... but it did not really fully open until around 200! I pulled it out a couple times around 200 and watched it slowly close and open. So I will have to get me a new gasket and re-install the thermostat and water pump. Should have done the fan check first! LOL I did rotate the water pump before removing it... but even though it turned freely, I was concerned that the blades might have been chewed up. Last pump I replaced had a lot of the blades destroyed! Which I am hoping that those chunks are NOTthe problem. I will probably get the install done, do the fan check this weekend, and will provide feedback afterwards. Thanks for all the help.

coolant temperature varies depending upon various factors among which are: ambient air temp; how the car is being driven, if the A/C is on.

Thus I have seen coolant temperatures from around 180F to 226F at various times and for long enough to know they were not transient temps but real given the circumstances at the time.

Sincerely,

MarcW.

Started the car and tried to determine if the fans where working ok. The passenger side fan seemed to fine... but the driver side seems to be a problem. I also waited for the car to hit the the tick mark around the 210 degrees. Heard the the passenger side fan kick up but still could not detect anything coming from the driver's side. If I remove the bumper cover; can I check the fan by applying power from my car charger? Could I possibly have both relays (low and high) failed? Can I swap the relays to see if the driver's side will work? Thanks

The problem was a bad contact on the drivers side fan. Was an easy fix after a lot of trouble shooting. Thanks everyone for your help.