930 Overheating

apen · 10-07-2021, 06:08 PM

Hello! I just recently picked up a 1979 930 turbo and am having some overheating issues! The car likes to stay right around the 9 o'clock position (middle of the tachometer) when driving on the freeway, but once I start driving in the city or get stuck in some traffic the car starts to heat up right to the red part of the thermostat.

I have taken the vehicle to a shop to get the two thermostats checked and both of them were functioning properly. I also had the timing of the vehicle adjusted so that it wasn't running to lean.

I have read through endless forum posts regarding overheating 930's, and am thinking of replacing my thermal reactors with free flowing headers and replacing the trombone in the right front fender with a Mocal Kit B oil cooler and fan.

I wanted to see if anyone has any experience with the Mocal kit and whether or not it would solve my problem. I have also heard about a lot of people running dual fender coolers in both of the front fenders. I wanted to see what you guys think about the single/dual setup and if its necessary to install another cooler. I am also open to any other suggestions of other cooler kits or modifications that could help keep the temps down.

Thanks!

Bucketlist · Bucketlist's Garage

I purchased a Mocal 44 row fender cooler kit and a spal fan from https://www.batinc.net/porsche several years ago because it gets 100* here in Texas and I thought it was running too warm. I installed it with a fan controlled by a switch in the dash. No problem since and only have to turn on the fan occasionally when running the a/c on a hot day.

apen · 10-09-2021, 02:42 PM

I purchased the 19 Row (310m) Cooler Kit that according to mocal "offer performance similar to our proven 44 and 50 row models at a more affordable price." In addition to swapping my thermal reactors with free flowing headers, I am hoping these will solve my over heating issue.

pkabush · 10-12-2021, 06:23 PM

You’ll not only solve your overheating problems but you’ll notice a nice increase in power due to the uncorked exhaust. Boost should come on significantly sooner. Which headers did you go with ?
Also, since no one else mentioned it, we need to lay eyes on your car. Pictures are mandatory.

apen · 10-15-2021, 10:11 AM

Got the cooler installed yesterday and it brought the temps down but still not where I want it to be. Going to get the headers installed this weekend so I will update you guys on that! I got custom headers from auto Atlanta!

ItzaMe · 10-15-2021, 12:17 PM

What did you pay for the car if you don't mind me asking, and how many miles?

I'm looking at a few.

s5uewf · s5uewf's Garage

have you checked fueling and timing? They may also affect engine heat, I would think.

apen · 10-15-2021, 04:28 PM

Supposedly the first shop that I took it to adjusted the fuel and timing but I didn’t really trust them after my experience there. Taking it to a well known shop (TRE Motorsport) in Los Angeles next week to get the headers installed and check the timing so we will see!

Tried installing the headers myself but some of the nuts on the thermal reactors were so hard to get to on the floor I gave up lol

908/930 · 908/930's Garage

Did you check your temp thermocouple and gauge to see if the reading close to correct temp?

Rawknees'Turbo · 10-15-2021, 10:24 PM

Maybe the shop that tested the thermostats checked, but one thing that can cause high running temps is that mice and rats like to build nests beneath the fan shrouding, on top of the cylinders and heads (I've even seen a pic where they used that area to store a large quantity of horse treats they had lifted from nearby). If you have a bore scope, you can easily see that area by passing the scope through the fan blades (can see a little of it using a small mirror and flashlight).