johnfm

Richard

i had a similar problem with my fan coming on - though I would only start the car for a minute & it would come on!! I replaced the temp sensor (£12) and it has not once come on after shut - down (the UK ain't the hottest environment in the world!!)

Re: spoiler shutter/curtain/wall thing - I definitely don't have one. Waht's the consensus on the group - is it work the £50 to restore what the previous owner removed??

<img src="confused.gif" border="0">

Richard 92 C2

Adrian

After looking at Randall's diagram of the temp guage I can indeed confirm that the temp was at 9pm on the day that this problem was found, Its now only a little over the 122f mark since I put the new "wall" in and will accept that this was indeed the problem...

Thanks for your assistance,

Randall, thanks for your input here too!

Regards

Adrian

Dear Richard,
I can tell you that the rear spoiler wall does not have that kind of effect at all. The temp change you are reporting is exactly what should happen when the oil cooler thermostat opens. I suggest you have an intermittant thermostat. This is mounted forward of the right rear wheel. I highly recommend you keep an eye on this,
Ciao,
Adrian
911C4

Randall G.

[quote]Originally posted by johnfm:
<strong>Richard

i had a similar problem with my fan coming on - though I would only start the car for a minute & it would come on!! I replaced the temp sensor (£12) and it has not once come on after shut - down (the UK ain't the hottest environment in the world!!)

Re: spoiler shutter/curtain/wall thing - I definitely don't have one. Waht's the consensus on the group - is it work the £50 to restore what the previous owner removed??

</strong><hr></blockquote>

Hi John,

Here's my opinion .... it really depends on:

-If you prefer how the car looks with the spoiler wall extended (i.e., in place).
-If you must keep your car completely original.
-Keep in mind it will split again at the folding joints every 4-5 years. The plastic Porsche uses in the folding joints is pretty crappy, and not very long-lived. You can extend the lifetime several years by applying black duct tape to the inside (non-visible) side of the wall. The black duct tape is much more robust than the original plastic.

One more thought. As I recall, 996s use a soft rubber, accordion-style spoiler wall. I'm guessing Porsche learned from 964/993s owners & dealers that the original style wall was failing too often, and that the new style "bellows" is supposed to be more robust.

Christer

Adrian/Richard and others:

FWIW, I had a split spoiler wall/blind when I purchased my car. I had it replaced at the service and the car runs slightly cooler at higher speeds - for example before it was replaced, cruising at 80mph the oil temp was a few degrees off the 8 o'clock mark, and after it was a nearer the 7.30 mark if that makes sense. It SEEMED to make a difference - not huge but noticeable....

Christer

Adrian

Dear Christer,
My problem with this thread and the spoiler wall is that the thread turned. The original fault was that the rear blower fan cranked up "5 minutes" or so after the engine is shut down. 964 is parked, not moving. This means excessive build up of heat from the engine in the heating pipes. This means that the spoiler is shut for at least this period of time. In reality the spoiler coul dhave been shut for quite some time before. I do not believe that the spoiler wall has anything to do with this fault. Randall runs without one.
For me it is more likely that the oil cooler thermostat did not open at all or the cooling fan for the oil cooler is not working (further explanation lower down) and Richard did not see the excessive heat build up before he stopped or simply the conditions were such that a system designed to protect the engine and the 911 against such things actually worked. Could be a combination of things.
However in the end it is not my 964, it is not my money and I can only offer advice based on knowledge and experience. I really hate to see people waste their hard earned cash. Just a personal thing of course.
The "PRIMARY" engine cooling system is the belt driven cooling fan backed up by baffles to direct the airflow around the engine.
Additional Engine Cooling is provided by the Rear Blower Fan also called the addition engine cooling fan.
Oil is used for internal cooling and the oil system has its own oil cooler which is activated by a mechanical thermostat and is provided with a 2 speed cooling fan.
The spoiler wall and spoiler affect are way down on the list. In fact I cannot find any reference at all to the importance of either item in the engine cooling process.
The only known electrical faults which would cause the fan to crank up in an uncommanded sense are the sensor in the pipes going intermittantly short or the blower motor relay sticking (very rare). These sensors are NTC. High temp, low resistance.
I still believe that what happened was supposed to happen. The engine was hot and the additional cooling protection cranked up. Why the engine was so hot needs looking at possibly. This is normally oil cooler related or a broken cooling fan belt.
Ciao,
Adrian
911C4

Christer

Adrian

FIne - I guess we got a a little off the beaten track - led by Richard himself actually...

Richard 92 C2

[quote]Originally posted by Adrian:
<strong>Dear Richard,
Yes the spoiler wall as you call it is part of the airflow system. I am surprised though that you did not notice this earlier on your engine temp indicator. It would be nice to have some figures on this for the future. I have to admit that I have not seen the spoiler wall cause such a problem before but hey, anything can happen and a lot depends on local environment as well,
Ciao,
Adrian
911C4</strong><hr></blockquote>


I dont think it was on purpose though, after this posting by Adrian I presumed I was on the right track! and that the "wall" was in fact the issue.

Regards

Adrian

Dear Richard,
That was what I call my politically correct answer when I do not agree but the poster seems convinced. I am no longer inclined to argue with people. I can only offer free advice and if people go off on other routes, then so be it.
However, the posts which followed, clearly identifies my concerns and I have expanded on those concerns.
Ciao,
Adrian
911C4

Randall G.

Hi Richard,

I think the best you can do right now is monitor your oil temperature, and don't be surprised if your rear blower starts running again after you've shut the engine off.

Speaking of engine cooling, have you ever verified your cooling system is working properly? While this won't tell you if you have an intermittent thermostat, it will tell you if everything is working at the moment. This simple check can be done idling in front of your house:

-Start engine, increase engine speed and/or place a blanket over the engine air intake to expedite warming of the oil.

-At ~194F, thermostat opens. Either feel for the right-front fender getting warm, or--better yet--pull the right-front mudguard and check to see if the lines to the cooler get hot.

-At ~212F, the oil cooler fan should start in slow-speed. This should be roughly midway between the 9:00 position and 248F mark.

-The oil cooler fan should run several minutes, cooling the oil to below the 9:00 position. The fan will then turn itself off.

Best of luck!