One known failure point that can leave you stranded in a 944 is the DME relay. The relay controls power to the DME (ECU) and the fuel pump. Most people just either constantly preemptively replace the relay as a wear item or bring a spare with them in the glove box just in case. The relay is mechanical and can therefore wear and eventually fail but there are thankfully better alternatives out there.
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| Focus 9 Technology Solid State DME Relay |
I picked up a modern solid state DME relay from Focus 9 Technology which is a direct swap for the OEM relay. Not only does it feature a solid state design that has no mechanical parts to wear, this version also offers a "pump prime" feature where putting the key in the on position, allows the fuel pump to prime for 3 seconds before you even start the car. This makes the fuel pressure perfect at start lessening the time it takes to get the car started. I also opted for the version with diagnostic LEDs. I can easily see when the relay is getting power, when it's pump priming and whether it's all working. Since my old relay is still working, I'm just keeping it in my glove box just in case anyway or to help a fellow 944 owner if they ever run into a DME issue.
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| Relay installed and pump prime mode |
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| Car running and relay fully active |
Looking at the car's service history I also noticed it's been more than a year since the oil was last changed on the car and it was looking a bit dark. The previous owner was using Valvoline VR1 20W-50 which is a really good oil with high zinc. I've personally been using Driven Racing Oil in all my Porsches also due to its high ZDDP values and I wanted to do the same here so I drained the oil and put in fresh Driven DT-50 which is 15W-50 oil. The car is noticeably running smoother with the new oil.
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| Fresh DT50 oil |
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| New Mahle OC142 filter |
The location and orientation of the oil filter means that it's a bit of a messy situation when removing. There's practically no way to remove it without dumping at least some point down below. I let the oil drain for about 3 hours in order to try and get as much of the oil out of the system and filter and that seems to have helped quite a bit. I also stuffed a bunch of paper towels around the base of the filter to absorb as much as I could. While I did have to do some cleanup, it wasn't as messy as I had originally expected.
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| Rennline fire extinguisher mount + Element E50 fire extinguisher |
I also keep a fire extinguisher in all my older vehicles for added safety. While the previous owner did have a larger fire extinguisher under the passenger seat, I gave it back to him before taking ownership since I prefer the Rennline mount and using the much more compact and easier to use Element Fire E50 fire extinguisher.
Maintenance Update:
Mileage: 96.410
- 6.5 quarts Driven DT-50 oil
