mcipseric

CADguy

The book explains many of the 993's systems: the oil system, the varioram system (for 96-98 cars) etc. which I find very interesting and useful.

Kika

there is no need to jack the car up to remove the headlights.

Dr. No

You know, it's funny, but when my car was overheating mid-way through an autocross event I was really happy that my instructor knew to disconnect the resistor and cool my engine before it needed a $10k rebuild. And he didn't even have to jack the car up, just open the hood. I thought it was more McGuyver than bush league. But that's just me I guess.

Garth S

Likely two issues to resolve ..

a) the ballast resistor that establishes the fans low speed on the front oil cooler is likely toast ... as Andreas said. Easy to check without crawling underneath - just open the CE panel ( front hood), and there will be two (tall black w. a #1 0n top) identical relays in the front row, hard right. Pull the one on the right ( relay R04), and alternately insert a jumper from where relay pin #30 plugs into ( different # on the panel) to the mate of pin # 87 .... and then pin #87c. One will be clearly the high speed .... and dead silence on the other if the ballast resistor is dead [ while there, do the same for relay R14 - identical set up for the two speeds of the AC condenser in the LF fender]

Personally, I'm not a fan ( pun pardon ) of deleting the low speed operation of either blower, as the low speed tempers the rate of heat rejection ---- if either oil or refrigerant is too hot, the thermo switch will bypass the ballast resistor, forcing the high speed operation automatically.

If the resistor is dead, with only the high speed available, the oil temp will jack about between too hot - too cool .... no moderation as intended.

Do those tests, and that part of the problem should be defined.

As to the "thermostat" .... there is a piston/spring style thermostat installed in the cast housing that connects all the plumbing/oil filter at the base of the oil reservoir: when the engine achieves core temperature ( ~88-90C IIRC), this mechanical thermostat opens .... and admits flow to the front oil cooler: if this is working, after ~ 10 min of gentle driving on a cold engine, one will see the oil temp approach the 194F mark as shown above - then fall back as the cold oil from the cooler lines, etc enters the flow ----- then the temp should stabilize as Alex said earlier.

If this thermostat is not working, it may stick closed ( too hot) ... or open ( too cool).

Anyway, you now have a visual test of its function re the oil tem gauge: if not OK, easy & cheap to replace ...

TMc993

I've found the book to be useful for certain very specific pieces of information (Specs, relay and fuse locations, etc.), but like anything in print, much of the information in the book has become dated over time. If you've got a workshop manual, you have access to just about every piece of data contained in the book.

As for current information on all things 993? Well, it's all right here on Rennlist...

Terry

Quadcammer

this is true, seemed like the pic was under the car and I didn't read the whole post.

Either way, flipping a switch in the cabin is still easier than removing the headlight.

yes, in an absolute pinch where you didn't previously know to install a manual fan control switch, its a fine "mcGuyver" idea.

However, would you prefer to pull your headlight out every time you think you might need the fan on all the time or simply use a switch in the cabin?

Matt Lane

Thanks for posting the pics. Very helpful as a short-term fix.

Best,

Matt