Overheating 996

[roperin]

I wish someone could give me a few ideas of what to do with a 2001 manual Cab that overheats. I did see coolant on the carport floor so i changed the coolant expansion tank and the cap, no improvement. this car runs fine, and temperatures run at about 185 for twenty miles or so, then it gradually goes up to about 200 degrees on the guage.

I spent today cleaning out the radiators, I did a thorough job, completely according to the video here, thanks. I got about a two gallon bucket of crap out of the radiators. Took it out for a run, same thing. About 195 to 200 degrees after twenty miles, of course the weather is hot already in Florida, today is about 90. The fans are running and when I stopped they were on high. I did have the air running. So i need to know what to do next, thermostat and water Pump ? Could it be anything else? I'd appreciate any and all ideas, thanks in advance. BTW I've had this car since last September and it didn't overheat at all during the winter and the guage used to sit at about 185 degrees.

Whats considered normal running temperaturee in an ambient of 90 degrees?.

Bob Leslie

Lakeland Fl.,

[white99c2]

In the heat of summer with A/C on my '99 C2 will run with the needle on the gauge past the zero in the 180. Is that where your gauge is reading?

[logray]

HI I think this has been covered many times (search), but 200 F is not unusual (thanks to California smog laws). Somewhere around just past the "0 in the 180" as per the previous poster.

That gauge is kinda funny anyways... if you have an older model you can even read out the temp on the A/C controls in Centigrade which is cool!

If it was truly overheating you would see codes and a flashing light on the coolant indicator (TURN the MOTOR OFF if this happens). (of course there could be lots of air pocket gremlins with an improperly filled system - search for Uview Airlift).

:lightbulb:

[fbgh2o]

A few of thoughts.

My car does seem to run a little hotter at highway speeds that at 45 mph.

If you did the tank yourself, are you sure that the cooling system is fully bled?

After chasing a cooling issue for months, I finally did the following:

• Cleaned radiators again
• New expansion tank (old one has a leak)
• New OEM expansion tank cap
• 160F thermostat and housing from LN Engineering.

This combination has has a significant impact on operating temperature. While I have not seen 90F outisde, it was 61F today here and the car ran steady 176F - 181F compared to 194F to 200F during the winter when it was regularly 0F.

[roperin]

A few of thoughts.

My car does seem to run a little hotter at highway speeds that at 45 mph.

If you did the tank yourself, are you sure that the cooling system is fully bled?

After chasing a cooling issue for months, I finally did the following:

• Cleaned radiators again
• New expansion tank (old one has a leak)
• New OEM expansion tank cap
• 160F thermostat and housing from LN Engineering.

This combination has has a significant impact on operating temperature. While I have not seen 90F outisde, it was 61F today here and the car ran steady 176F - 181F compared to 194F to 200F during the winter when it was regularly 0F.

Thank You guys, I do appreciate your comments,to answer your questions, yes i am sure the cooling system was bled correcly after installing the new coolant Expansion tank because i didn't drain the engine block ,I just drained the engine until the expansion tank was empty, then i stopped draining so there could not be any air in the system. I don't think so anyway and i had the car jacked up just at the back so it was on a severe slope downhill when i did the work, also i opened the purge valve before i took it for a test drive. I noticed yesterday that the new expansion tank cap is not OEM, its made in Germany and its new but made by some outfit called Fluer or something like that. It looks identical to the OEM piece that was on the car when I got it, maybe I'll try the old cap on the new tank, good.

The car does not leak any coolant any more. I will get on L & N's website to find out more about the 160 degree thermostat, i'm really worried about this so i guess new water pumps and thermostats are in my future,geez I thought cleaning the radiators would for sure fix it, there was so much crap in there. I'll do the water pump just to ease my mind. Anyone know anything about the water pumps advertised as having metal impellers? is that a good deal? Is the OEM one have rubber impellers ?

[white99c2]

Here are 2 mods I did to end the madness I was going through while driving and staring at that temperature gauge. The first is a snap to do, its a switch you can use to turn on the radiator fans on high speed. The second is a jumper wire between the low speed fan relays and the high speed, so when you don't use the switch mentioned above the fans are set to come on low speed at around 205 degrees, this hack makes high speed come on instead of low speed and cools down much quicker.

Also. I don't know where you live but it must be Florida with 90 degree temps yesterday, I drained out 3 gallons of coolant and added 3 gallons of distilled water and on bottle of "Wetter Water" it helps lower coolant system temps, read about it.

All of these trick helped my '99 stay cooler, no more staring at the gauge. In bumper to bumper traffic with A/C on, its going to run hot so just accept it but after a few minutes of open road driving it should maintain. In the summer I call my car Inferno.

http://www.6speedonline.com/forums/996/204627-radiator-engine-fan-mods.html

http://www.ppbb.com/phorum/read.php?6,1509504,1509681

A few of thoughts.

My car does seem to run a little hotter at highway speeds that at 45 mph.

If you did the tank yourself, are you sure that the cooling system is fully bled?

After chasing a cooling issue for months, I finally did the following:

• Cleaned radiators again
• New expansion tank (old one has a leak)
• New OEM expansion tank cap
• 160F thermostat and housing from LN Engineering.

This combination has has a significant impact on operating temperature. While I have not seen 90F outisde, it was 61F today here and the car ran steady 176F - 181F compared to 194F to 200F during the winter when it was regularly 0F.

Thank You guys, I do appreciate your comments,to answer your questions, yes i am sure the cooling system was bled correcly after installing the new coolant Expansion tank because i didn't drain the engine block ,I just drained the engine until the expansion tank was empty, then i stopped draining so there could not be any air in the system. I don't think so anyway and i had the car jacked up just at the back so it was on a severe slope downhill when i did the work, also i opened the purge valve before i took it for a test drive. I noticed yesterday that the new expansion tank cap is not OEM, its made in Germany and its new but made by some outfit called Fluer or something like that. It looks identical to the OEM piece that was on the car when I got it, maybe I'll try the old cap on the new tank, good.

The car does not leak any coolant any more. I will get on L & N's website to find out more about the 160 degree thermostat, i'm really worried about this so i guess new water pumps and thermostats are in my future,geez I thought cleaning the radiators would for sure fix it, there was so much crap in there. I'll do the water pump just to ease my mind. Anyone know anything about the water pumps advertised as having metal impellers? is that a good deal? Is the OEM one have rubber impellers ?

[logray]

Using the search feature, I found these really great threads (some of which I've visited many times before).

Seriously though, read these through threads and try using the search feature! It really is great! :)

http://www.renntech.org/forums/index.php/topic/4476-normal-operating-temperature

http://www.renntech.org/forums/index.php/topic/1171-engine-operating-temp-range

http://www.renntech.org/forums/index.php/topic/33374-temperature-gauge

http://www.renntech.org/forums/index.php/topic/32522-160f-thermostat-on-996-34-with-california-smog

[c70Pete]

I hear running pure distilled water AND the water wetter product is the way to go!

but be sure to put coolant back in the system in before winter time...

[roperin]

Thanks for everyones replies, i have ordered a thermostat and a water pump and its due to get these this weekend, so i'll be certain to be advising of any success next week, and i'll get the system flushed as well.

[roperin]

oK, HERE WE ARE ON sUNDAY AFTERNOON, THE SEVENTEENTH OF aPRIL, sorry about that, we have the water pump loose, its about to come off and i'm trying to follow the video closely, I have done everything with the engine carrier brackets and I have the engine jacked up a littel and my question is, the engine carrier bracket thing that goes from the engine mount to engine mount has all its nuts and bolts loose but why should it move? its attached to the engine mounts, it wont move, the engine wont move because of the front engine mounts so whats all this about move the engine carrier bracket forward? Towards you i would imagine. I would need to loosen the engine carrier bracket from the engine and from the engine mounts but the video doesnt say anything about loosening the bracket from the engine mounts. and the pump wont come out until the engine carrier bracket is out of the way. I'm stuck guys, i am not able to figure out what to do, HELP !

[allenh5]

oK, HERE WE ARE ON sUNDAY AFTERNOON, THE SEVENTEENTH OF aPRIL, sorry about that, we have the water pump loose, its about to come off and i'm trying to follow the video closely, I have done everything with the engine carrier brackets and I have the engine jacked up a littel and my question is, the engine carrier bracket thing that goes from the engine mount to engine mount has all its nuts and bolts loose but why should it move? its attached to the engine mounts, it wont move, the engine wont move because of the front engine mounts so whats all this about move the engine carrier bracket forward? Towards you i would imagine. I would need to loosen the engine carrier bracket from the engine and from the engine mounts but the video doesnt say anything about loosening the bracket from the engine mounts. and the pump wont come out until the engine carrier bracket is out of the way. I'm stuck guys, i am not able to figure out what to do, HELP !

I used this tutorial, and had very little trouble replacing my water pump.

http://p-car.com/996/diy/waterpump/

[roperin]

Ok, I finished with the car and here is the "Rest of the Story "

Removed the front bumper and cleaned the radiators,, no change.

Replaced the thermostat and the water pump, both were in fine condition but i replaced the original parts with a metal impeller pump and a new thermostat, which I checked first and it did open at 83 degrees. also changed the hoses from the water pump and the thermostat housing, i had replaced the coolant expansion tank a couple of weeks previously. the problem i had with the engine carrier bracket in not being able to move it to the rear an inch , was that i had not raised the engine sufficiently to take all the load off the engine carrier bracket. once you get the main 15 mm bolts bracket to engine centered in the bracket holes, it does move easily.

Since i couldn't find anything wrong with any of the parts i replaced i checked the water hoses very carefully.

i found a hole in the hose coming from the coolant expansion tank where it curves at a 90 degree angle to the bottom of the engine, i'll try to post a photo. Don't seem to be able to.

So i suppose the problem was the hose all along,the car runs at about 190 degrees now in 92 degrees ambient. Thank you very much to all who participated in this DIY, this site is wonderful, I contributed another $25, Thanks Loren.

Edited April 23, 2011 by roperin

[logray]

a metal impeller pump

Could you please provide details? P/N and who you purchased it from?

TIA.

[roperin]

iTS PART NUMBER 996 106O 1155, EBAY SELLER nUMBER 48673, duetsche parts USA, I'll updaTE YOU ON HOW GOOD IT IS IN SIX MONTHS. but i couldn't see any difference in the casting or the pulley or the pump vanes except maybe the vanes are a little taller which ought to make it pump more water, GREAT !

And its only $107 Great !

Edited April 24, 2011 by roperin

[ziiz996]

FOLKS!

The 996's will always run warm. Do not bother with changing thermostats and fan switches. The solution is sOimple....

CHANGE BOTH RADIATIORS. PERIOD. THIS WILL RESOLVE YOUR PROBLEMS 100% (ASSUMING YOUR COOLANT BOTTLE, AND CAP ARE NOT DAMAGED.

COMPLETELY DRAIM AND REFILL COOLANT WITH PORSCHE PINK COOLANT. DO NOT ADD 50% WATER... JUST COOLANT... RADIATORS ARE INEXPENSIVE.. I DID IT TO MINE. AND THE TEMP IS TO THE LEFT OF THE 8 IN THE 180 GAUGE. IF I PUSH THE CAR, THE WATER PUMP ACTUALLY COOLS THE SYSTEM EVEN MORE. WHEN I GET BACK TO NORMAL DRIVING, THE TEMPERATURE RISES TO MID 8 IN THE 180 THEN GES BACK TO THE LEFT WITHIN 2 MINUTES.

I GUARANTEE IT.......

[logray]

Water has better heat dissipation than coolant. You should not run 100% coolant.

When you say you changed the radiators, what parts did you replace them with?

[ALLSPEED]

Isn't the wet carpet a sign for a leaking coolant tank on a Boxster? Just trying to learn.

Edited September 30, 2011 by ALLSPEED

[Loren]

Isn't the wet carpet a sign for a leaking coolant tank on a Boxster? Just trying to learn.

If the carpet is wet in the rear trunk of a Boxster it is likely a cracked coolant tank.

Carrera's leak just behind the left rear wheel.

[ALLSPEED]

Thanks for the clarification.