90s2

HI.
My 90S2 Has the coolant being feed around the throttle body as a measure of preheating the air to speed up the heating up of the motor process.
Now is there a thermostat for this routing..reason why i ask is that mine is hot all the time.
And that just seems like a bad idea to preheat the intake air in all the time.
I am trying to pin point the reason why my 944 runs kinda hotish.. a little above the middle mark on highway speeds.

thank you

Z-man

I believe there is no thermostat - the coolant will constantly flow through the throttle body. It's design is to prevent icing - where the barn door flapper in the throttle body gets frozen shut. Unfortunately, it does warm up the air going into the engine - which theoretically robs the car of some power (0.005 hp loss is my guess). You can bypass the coolant running through the TB by simply connecting the in/out hoses like this:



We were hunting down a coolant leak (which turned out to be a cracked head), and bypassed the throttle body to ensure the leak wasn't there. Since I don't drive my car that often in the cold, I kept it that way - for that extra 0.005 hp gain.

-Z-man.

bleucamaro

I bypassed my TB coolant line as well. Has there ever been any "stop leak" type product used that could be clogging the radiator?

90s2

Yes that is my next step..
i replaced the thermostat on the WP and same deal..bled all the air out 1hr+
but at idle there seems to be very little flow of coolant coming out of the bleeder nut up top...
short of a bad wp which is less then 20kmiles i shall try a new radiator.
Thank you

AznDrgn

Try back flushing it first before you buy a new one.

90s2

Im sorry ?back flushing?

Clint's 944

Does the temperature fluctuate or is it constantly higher?

FWIW, You can also remove the fans and blow air back through the radiator fins from the engine side. It's amazing how much dirt will be in there!

AznDrgn

to backflush a radiator basically you disconnect all the hoses and then you hook up a hose to the lower radiator hose port and start pumping water backwards through the radiator. Since the flow is backwards from what it's normally got and you'll be using a lot more pressure and volume than normal sometimes it's enough to clean out obstructions.

90s2

Ah ok
well i will be removing the radiator and trying to see if the flow is ok or not.. i shall try back flushing it too..
The temp is constant..does not change much.. turning on the heater does not make it go lower.. and when i get off the highway it gets a bit hotter...the fans do kick in and cycle on and off..
thanks for all the help

stolarzj

Not sure it's the same on a S2, but I was having a running hot issue on my 968. The fans would come on and off like normal and I would hear the high speed fan alot. I saw a post about cleaning the connections to the two ballast resistors for the fans. They are hockey puck shapped and are attached to the firewall to the right of the battery. When I pulled the connections for the first one the connections crumbled in my hand, the second was ok. I cleaned and replaced the connectors and my cooling problem is gone and I rarely hear the high speed fan now. I might be worth it to check it..

Josh

Z-man

Are they constantly cycling one and off? If so, there is a short in the system - I had that problem a couple of years ago.

I'm going out to lunch now - I'll note where my temp guage is. Perhaps it is your thermostat, but when they fail, they are supposed to fail in the open position. You could replace your thermo with one that opens at a lower temp.

-Z

90s2

No i meant that the fans turn on and eventualy off..normal cycling..
And i did replace it with a 80 C thermostat...it made no difference..maybe a bit worse indeed..im thinking radiator..cause the intake rubber hose that attaches to the WP keep prety cool..indicating lack of flow..and since the thermostat is new im guessing radiator.

Z-man

A little above the middle mark isn't that bad - that's about where I run on warmer days at highway speeds. On the track, I'll actually bump up into the top white mark as well, on hot days when I'm running the car hard.

If your fans turn off, that would mean that the car is at normal operating temps, unless your fan sensors are giving you a false reading. Given the position of your temp gauge, I think they are working fine.

Coming into work today with ~40 degree outside temp, the temp gauge was even with the middle mark. Where do you live, and what outside temps have you been seeing?

Do you have a front license place? If so, remove it until you figure out what the problem is, if there is actually a problem. See if that makes a difference - as the plate blocks about 1/3 of the airflow going to the radiator.

If your H2O pump is shot, you'd be running much higher than what you describe. If the impeller isn't working inside the pump, you'll definately over-heat in short order. (Been there, done that).

I really don't think you have a problem. Going through all that trouble to determine that everything is in working order may be a little overkill.

-Z-man.

bleucamaro

It took you over an hour to bleed the system??? Mine took less than 5 minutes, basically when the thermostat opened it was done.