Boxster 986 - Cooling Fans, Operating Temp. (Stage 1 & 2)

[ooid]

Is there a quite specific degree or level for Stage 2 fans? The car's manual also quite vague about this.

I've recently discovered my stage 2 fans (the loud ones) does not start even hitting the heating level between "80&120". It used to start quite loud, right after 80 (near right side of 0) but since the engine rebuilt, it operates generally between 80-90 but never heard the high fans starting?

Today after about 1 hour driving in the city, (11 miles maybe in total) the level hit the "line" between 80-120 but no fans? it was slowly going down though not sure why, maybe AC?

- Tried to check if the resistors working by turning AC on, but can not hear any fans noise, as the engine quite loud already.

PS: Coolant level is up, no funny smokes, smells or weird action on the engine revs.

[bgunn]

Stage one operates just as the needle sits to the right side of the '0' of '80' - the fans should operate when the A/C is on too.

Mine didn't have any stage one fans when I first got it as both resistors had died, and as you note, the fans didn't operate until the next 'tick' on the gauge - which is rather hot.

[Piersman2]

There should be no fans with a cool engine and A/C off.

Turn on A/C and you will have half fans both sides.

Leave engine to warm up and you should get full fans both sides - eventually!

I had to replace one of the thermistors on mine under the front bumper as only 1 fan was operating as above when I first got it.

[ooid]

Thanks all.

Yes the loud fans just started today after hitting the line between 80-120. (The traffic was a nightmare today, did about 11 mile in 50 mins, thanks to london road-works)

Looks like both balast resistors dead. OPC quotes me 400 GBP for replacing them.

Original resistors cost 150 GBP and my local garage offered to replace them free of charge if I order the parts by myself

Edited by ooid on Sunday 1st May 14:21

[Piersman2]

ooid said:

Thanks all.

Yes the loud fans just started today after hitting the line between 80-120. (The traffic was a nightmare today, did about 11 mile in 50 mins, thanks to london road-works)

Looks like both balast resistors dead. OPC quotes me 400 GBP for replacing them.

Original resistors cost 150 GBP and my local garage offered to replace them free of charge if I order the parts by myself

Edited by ooid on Sunday 1st May 14:21

The resistors are not cheap are they! I actually ordered a complete fan assembly second hand for mine assuming I could take off the resistor to fit to my car. Unfortunately the resistor pack fitted to the used fan assembly that was delivered was also faulty, so I ended up getting a second hand fan for nothing and then having to order up a resistor, new, on it's own.

[Rockster]

ooid said:

Is there a quite specific degree or level for Stage 2 fans? The car's manual also quite vague about this.

I've recently discovered my stage 2 fans (the loud ones) does not start even hitting the heating level between "80&120". It used to start quite loud, right after 80 (near right side of 0) but since the engine rebuilt, it operates generally between 80-90 but never heard the high fans starting?

Today after about 1 hour driving in the city, (11 miles maybe in total) the level hit the "line" between 80-120 but no fans? it was slowly going down though not sure why, maybe AC?

- Tried to check if the resistors working by turning AC on, but can not hear any fans noise, as the engine quite loud already.

PS: Coolant level is up, no funny smokes, smells or weird action on the engine revs.

You can't rely upon the in-dash coolant temperature gage for anything other than knowing the engine is cold, or up to some operating temperature -- which varies depending upon ambient temperature and how the car is being operated -- or if the temperature is climbing. Even if the needle climbs quite high my info is -- relayed from the factory to me by my dealer -- if there is no warning light there is no overheating problem. (My query to the factory was prompted by driving some hours in 116F heat in the desert southwest with the coolant temperature at a constant 226F with the radiator fans on full speed 100% of the time and the engine compartment fan running all the time. The temp gage needle went to the right into an area I had never seen it into before. But no warning lights.)

By using an OBD2 code reader/data viewer/logger connected to my 2002 Boxster's OBD2 port I found the fans come on low speed at 212F and high speed at 216F. They switch off at 205F.

[ooid]

Piersman2 said:

The resistors are not cheap are they! I actually ordered a complete fan assembly second hand for mine assuming I could take off the resistor to fit to my car. Unfortunately the resistor pack fitted to the used fan assembly that was delivered was also faulty, so I ended up getting a second hand fan for nothing and then having to order up a resistor, new, on it's own.

I have a better solution. They should just ban TFL bus, vans and slow-ass construction trucks from central London! ..Seriously, my temperature does not go above "80" until I hit another traffic jam. Not the mention, most of the routemasters half empty actually,they just cause more congestion.

It was like a "fan" symphony of the cars in traffic today, when I open my driver side window and listened to all other cars, running fans to keep things cool

By the way, did you buy those "24 GBP" used once from ebay? it says they are working, but looks like they are dodgy!

Edited by ooid on Sunday 1st May 23:57

[Piersman2]

ooid said:

I have a better solution. They should just ban TFL bus, vans and slow-ass construction trucks from central London! ..Seriously, my temperature does not go above "80" until I hit another traffic jam. Not the mention, most of the routemasters half empty actually,they just cause more congestion.

It was like a "fan" symphony of the cars in traffic today, when I open my driver side window and listened to all other cars, running fans to keep things cool

By the way, did you buy those "24 GBP" used once from ebay? it says they are working, but looks like they are dodgy!

Edited by ooid on Sunday 1st May 23:57

No, I bought mine from 911 Design for about £90. I didn't want to dick around after the failure with the complete assembly second hand.

I think that if you A/C is working and blowing half speed, it would need to be a warm day to need the full blower to cool the engine down.

[ooid]

I've done a total of 120 miles today on m11. No congestion, traffic or non-sense stopping, usually between 50-70 mph. The gauge never went beyond "8" of 80. The same gauge usually operates between 80 & 100, in central London due to low-speed zones and massive congestion in less than 30 mins driving, and if the weather is quite hot, the high fans kick-in.

I might be wrong but really it might explain how most of these cars have engine issues if they are being driven in the city for a long time.

[gsewell]

Rockster said:

By using an OBD2 code reader/data viewer/logger connected to my 2002 Boxster's OBD2 port I found the fans come on low speed at 212F and high speed at 216F. They switch off at 205F.

If I remember my physics and old units correctly, 212'F is 100'C and a pressurised system is not an issue until well above this value. So if fans kick in at that temp then all should be good. If concerned, then I seem to remember that the Hartech web site advocates not doing traffic light grand prix starts as it takes a few seconds to start to dissipate the heat at low revs or to use a lower temp thermostat to keep the coolant flowing earlier.

[Rockster]

anonymous said:

[redacted]

To some extent that is correct, but I find it a bother to try to distinguish how far the needle is past the "180" hash mark and thus calculate -- try to remember -- what coolant temperature this signifies.

Thus I don't pay the gage that close attention other to note the needle is at the "180" hash mark and to then continue to drive the car some to ensure all the oil is fully up to temperature before I give it the whip.

While the needle can move quite a bit climbing up past/beyond the hash mark then falling back closer to the hash mark I don't pay it much mind other than to make sure it doesn't keep climbing moving to the right.

[Rockster]

gsewell said:

If I remember my physics and old units correctly, 212'F is 100'C and a pressurised system is not an issue until well above this value. So if fans kick in at that temp then all should be good. If concerned, then I seem to remember that the Hartech web site advocates not doing traffic light grand prix starts as it takes a few seconds to start to dissipate the heat at low revs or to use a lower temp thermostat to keep the coolant flowing earlier.

I'm not concerned. In the summer where I live amibent temperature can reach/break 100F. I admit though once I was concerned. Once when I found myself driving my Boxster in 116F heat in AZ one fine hot July. Engine coolant temperature was 226F. Intake air temperature was 135F. The fans were on high all the time. Even the engine compartment fan was running all the time.

The temperature gage needle was to the right but I can't recall now how far. I don't think to red zone. None of the waning lights ever came on. I drove hundreds of miles through that heat -- at highway speeds (75mph+) -- and made it home. The Boxster never complained but I sure did. Blasted hot that day. That was years ago and the car was fine. Since them both cars have been in high and in a few cases even higher temps: 118F in the Turbo again in AZ -- with no ill effects.

As long as the cooling system is leak free and can hold pressure the high temperature is not a big concern. If the system can't hold pressure this can let the hot coolant flash to steam at the hottest places in the heads. This steam can block coolant flow to these hottest areas and engine damage can occur. It is the pressure the coolant is under when hot, or should be under at any rate, that keeps the coolant from boiling. The anti-freeze is there as protection against, well, freezing, and to provide some anti-corrosion protection and to provide some protection/lubrication to the water pump seals.

I drive my cars like I want in the heat. Had to Turbo up to 165mph even. Sometimes I drive my Boxster or Turbo pretty hard in the mountains on the roads near where I live. No big deal. 143K miles on the Turbo and over 300K miles on the Boxster.

Edited by Rockster on Thursday 5th May 07:08