improved engin cooling for a 993 c4
 

I live in southern California. I recently purchased a 993 c4. During the summer while in traffic the engine temperature will go up but not to the red line. I am thinking about installing the turbo front bumper with the turbo inlets where the fog lights are and the turbo rear wing/engine compartment lid to provide more room for air circulation and a fixed rear spoiler to help cool the engine. any thoughts or suggestions

The stock engine cooling (oil/air) is pretty effective.

What temps are you seeing (o’clock needle position) that make you concerned? And in what circumstances? Your “not to redline” doesn’t tell us much.

First thing to do is make sure your cooling mechanisms are working properly. Does the oil cooler fan operate in high and low speeds (resistor ok?), is the oil cooler heat exchanger clean, has the engine under tray been removed?

Your fixes will not solve any underlying problem if there is one. In my opinion the turbo bumper on a NB looks great. The fixed wing is a bit of overkill.

Start with your ballast resistors and go from there.

If that comes up negative pull the alternator & engine fan and remove the mouse nest on top of the cylinders.

The Clewett belt kit provides more air flow than the old v belt.

When the engine is at normal temperature, the oil temperature needle is between 8 and 9 o'clock (closer to 8 though). When I am sitting in traffic at idle and the engine heats up, the needle is at 9 o'clock. Which temperature have you seen?

As long as it is not in the red, especially while driving, everything is completely fine. Don't overthink it. None of what you've mentioned modifying will have any perceived effect. These cars have been around for over two decades and survive even hotter climates than yours.

See here for full breakdown: https://www.pelicanparts.com/techart...20(red%20arrow).

Excerpt:https://cimg8.ibsrv.net/gimg/rennlis...04c2f442e0.jpg

thanks for the responses. temps range between 8and 10 on the clock. never in the red/orange, during cool weather just below 8 than can get just below 9. never have had it yet in traffic in the summer with the a/c on. will test it this summer. thinking of still putting the turbo front bumper on with the turbo fog lights. like to look. so looks like my c4 is fine. thanks again for the input.

Put the bumper on if you like the look, but it has zero affect on cooling. You need to check if your oil cooler fan is operating properly (it has two speeds). Your temp should not be getting even close to red.

Agreed. And clean out dried up leaves and debris blocking the front of your oil cooler. You can peep through the front bumper.

I installed a fan override switch. Easy mod and very effective.

https://www.google.com/search?q=pors...t=gws-wiz#ip=1

Hi James,
If your temp gauge creeps to slightly above 9:00 when idling in traffic in hot weather this is normal. If under such conditions your oil pressure dips below 2 bar I would use a thicker oil such as a 50 weight to ensure good lubrication, Other than this I am not sure any added actions to cool the engine are required. Here is a page discussing how to read the gauges:
https://993servicerepair.blogspot.co...-leveloil.html

Andy

"he turbo front bumper with the turbo inlets where the fog lights are".
This will not do much if anything for driving in traffic temps.

I agree with checking health of the engineered system, beginning with the ballast resistors.

You can also wire one of the fans (maybe both) so it is always on.
I did that, but it so many years ago I don't remember the details......................................................
It made a difference in traffic and track days.


There ya go, read what Chuck posted.

Craig


See post #11

https://rennlist.com/forums/993-foru...rride-mod.html

This will take care of your concerns. Cost about what a wide-body front bumper and paint would cost.

https://www.carnewal.com/products/96.../GT-Oil-Cooler

It will not take care of his concerns if his oil cooler fan isn't working correctly. If it is working, the stock cooling setup is very effective. It's probably not working. So installing another oil cooler isn't really the way to proceed here.

If you are getting caught in traffic on hot days and the engine is getting hotter than you like wire a high speed fan over ride switch, don't wire an always on, which will just put wear on your fan unnecessarily.

It sounds like the temps you're running are somewhat normal.

I'll add that when I lived in Phoenix several years ago I had a conversation with the lead mechanic at Stuttgart Southwest about summer temps. He stated that temperatures in the desert southwest (Phoenix, Las Vegas, etc) can really push 964s and 993s to the limit and that they really benefit from additional cooling. He went on to say that on a hot summer day climbing a long incline or mountain pass it wouldn't be unusual to get some pinging/detonation. The problem is the engine is such a noisy beast you'd never hear it.

I heard it myself if I drove close alongside a high wall (driver's side) with the window rolled down, hard acceleration on a hot summer day. I always used 91 octane which was the highest available in PHX. Without that wall next to me I never heard it. I added the Turbo S oil cooler and it made a noticeable drop in oil temps.