Experiencing a car issue can be frustrating, whether it’s in the virtual world of Car Mechanic Simulator 2018, where your diagnosis box is your best friend, or in real life with your own vehicle. Recently, I faced a ‘Coolant Fault’ warning in my Porsche 991.1 Carrera, a situation that reminded me that even outside the game, accurate diagnosis is crucial. This experience highlighted how understanding diagnostic processes, much like mastering the diagnosis box close feature in the game, can help tackle car problems effectively.
It started during a spirited drive while testing new Girodisc brakes. Pushing the car a bit harder than usual, the dreaded ‘Coolant Fault’ message appeared on the dashboard. This was a first for my Porsche, and it happened right before a planned high-performance driving day – timing couldn’t have been worse!
My first step, mirroring how we might approach issues in Car Mechanic Simulator 2018, was to pull out my diagnostic tool – in this case, a Foxwell NT530 scanner. Just like the diagnosis box in the game helps pinpoint problems, the Foxwell scanner revealed the fault code: P1433, indicating a vacuum leak.
Interestingly, despite the ‘Coolant Fault’ warning, the code pointed to the vacuum system. Modern cars utilize vacuum systems to control various components, from thermal management to exhaust valves. These systems often employ Change Over Valves (COVs), electrically controlled solenoids that manage vacuum actuation. So, a ‘coolant fault’ could actually stem from a vacuum issue affecting a thermal management component.
My Porsche 991.1 C4S has eight COVs in its vacuum system. Understanding the layout of these valves is like knowing the parts layout in Car Mechanic Simulator 2018 – essential for effective troubleshooting.
Research suggested that vacuum leaks in COVs, their connecting pipes, or even disconnected pipes were more probable than electrical failures. A common culprit for disconnection is the pipe for the exhaust flaps. My friend Peter, thankfully available to assist, checked the exhaust flap pipes underneath the car, but they were secure.
To further investigate, I used the ‘Active Test’ function of my Foxwell scanner. This allowed me to isolate and test each COV solenoid individually, similar to how you might test components in Car Mechanic Simulator 2018 after an initial diagnostic scan. Each COV passed the active test, ruling out electrical solenoid failure.
With Silverstone fast approaching, and the fault appearing intermittent, I cleared the code and conducted a test drive. Driving the same route where the fault originally occurred, including a particularly rough section of road, it reappeared. However, given the upcoming track day, I cleared the code again and decided to proceed, hoping it was not a constant issue.
At Silverstone, the Porsche performed flawlessly. Despite rigorous driving in Sport and Sport Plus modes, temperatures remained normal, no codes reappeared, and the car ran perfectly. This further suggested the fault was not continuous, but rather triggered under specific conditions.
Back home, wanting to address the issue properly, I prepared for a more thorough inspection. This involved removing the rear bumper, active spoiler, and air-box to access the COVs. While more involved than clicking through menus in Car Mechanic Simulator 2018, it’s a process any competent DIY mechanic can undertake with some basic tools and caution. Remember to consult online guides or manuals if you’re unfamiliar with these procedures.
Removing the air-feed pipes, electrical connectors, and air-box provided better access to the COVs located on top of the engine. Each COV has three connections: an air inlet, a vacuum outlet to the controlled component, and a common vacuum inlet.
Using a vacuum pump, we tested each accessible COV. We couldn’t reach the two COVs located underneath on the PDK (for heat exchangers) without a lift. All tested COVs maintained a vacuum of -25 to -27 inHg for 3 minutes, indicating they were holding vacuum correctly in a static test.
During disassembly, we noticed a plastic vacuum pipe, often disconnected when removing the air-box, felt loosely connected to its rubber T-piece. Additionally, the pipe connecting the two COVs on the air-box (for the Acoustic Simulator and Air Cleaner Flap) wasn’t fully seated. A visible black ring on the plastic pipe indicated it should be pushed further into the rubber connector.
We then tested the accessible vacuum pipework for leaks, and it initially seemed fine. However, considering the loose connections and the fault occurring on rough roads, a theory emerged: vibration combined with slightly loose pipes might have caused a momentary vacuum loss, triggering the fault. Even a brief vacuum loss can be enough to trigger the P1433 code.
While a smoke machine can be used to pinpoint pipework leaks, it’s not a common tool for home mechanics. In this case, focusing on the suspect connections seemed like a reasonable approach.
Conclusion & Solution:
Given the circumstances – the fault appearing on a rough road and the loose pipe connections – vibration-induced vacuum loss seemed plausible. The fact that the car performed perfectly at Silverstone after clearing the code also supported this idea.
To address this, I replaced potentially aged rubber fittings with new OEM parts, fully seated the plastic pipes, and added zip ties for extra security. This is akin to tightening bolts and ensuring secure connections after repair in Car Mechanic Simulator 2018, but in the real world.
Since then, I’ve driven approximately 200 miles across various road types without the fault reappearing. While I haven’t revisited the exact stretch of rough road yet, initial signs are positive.
It’s important to remember that ‘Coolant Fault’ warnings can have multiple causes, and this solution is specific to my car’s situation. Faulty COVs, rusty COVs, leaking pipes, coolant cap issues, or even thermostat problems can all trigger similar warnings. Porsche even issued a Technical Bulletin in 2015 recommending specific part numbers for COV replacements based on location, suggesting complexity in the system.
This experience underscores that diagnosing car issues, whether in Car Mechanic Simulator 2018 using the diagnosis box close feature or in real life, requires a systematic approach. Understanding the systems, using diagnostic tools effectively, and paying attention to detail are key to finding the right solution for your car’s specific problem.
Mark Davis (AKA: 911Time)
Note: Special thanks to Peter for his invaluable assistance and hard work on this diagnosis and repair process.
