When a vehicle begins to underperform, it’s not just frustrating—it can also be a source of concern. At D & D Mechanical & 4WD in Goolwa, we pride ourselves on taking the guesswork out of car troubles and restoring our clients’ confidence in their vehicles. This case study outlines one such instance, where a misfiring engine and an unexpected discovery led to a challenging yet rewarding repair.

How D & D Mechanical & 4WD Diagnosed and Resolved a Mysterious Engine Issue

A local Goolwa resident reached out to D & D Mechanical & 4WD with complaints about their car - V6 Holden Commodore - misfiring at low revs, struggling under load while driving uphill, and experiencing cold start issues. With these symptoms, we booked the vehicle in for a comprehensive diagnostic and test service.

To kick things off, we connected our scan tool to the vehicle and retrieved the following fault codes:

We road-tested the vehicle to replicate and confirm the symptoms, cleared the codes, and re-scanned the system back at the workshop. Once the fault codes reappeared, we knew it was time for a more in-depth investigation.

After removing the spark plugs, we found them fouled with fuel, particularly on the right leading bank of the V6 engine. From there, we suspected a potential injector fault, which prompted us to remove the intake manifold for further inspection.

What we uncovered under the bonnet was more than a simple injector fault—it was a bizarre and unexpected issue. Nestled under the injector rails were two deceased rats that had set up a makeshift nest. Unfortunately, during their time there, the rodents had chewed through wiring and fuel lines, causing significant damage.

We immediately contacted our client to share the findings and discuss repair costs. The discovery of the rats prompted curiosity, but neither the client nor our team could pinpoint a reason why the rats had chosen the engine bay as their home. However, the client did mention their dog had been growling and hanging around the car in recent weeks—a clue we all pieced together in hindsight.

At D & D Mechanical & 4WD, we don’t just fix problems; we ensure vehicles leave in better condition than when they arrived. First, we removed the fuel rail and cleaned out the nest and remains of the rodents. Then, we repaired the wiring and fuel lines that had been damaged by the chewing.

Once reassembled, we performed a thorough retest and found an additional issue—a fuel leak at a pressure return hose at the end of the fuel rail. We immediately ordered a replacement hose, installed it upon arrival, and conducted further testing. With all faults resolved, we cleared the codes, completed the reassembly, and carried out a final road test to ensure the car was running perfectly.

Thanks to the meticulous work of the team at D & D Mechanical & 4WD in Goolwa, the client’s car was returned to them in peak condition. The engine misfires were resolved, the fuel system was functioning optimally, and the vehicle’s overall performance was dramatically improved.

Our client was thrilled to have their car back on the road and running better than ever. While the discovery of the rats added an unusual twist to the repair process, it was a reminder of the importance of comprehensive diagnostics and thorough repair work.

For this repair, D & D Mechanical & 4WD in Goolwa ensured that every step of the process was carried out with precision. Beyond resolving the engine misfires, we advised the client to be vigilant about signs of rodents in and around their vehicle and home. It appears that this issue can affect those living in a suburban setting and not just in rural, farming locations as you would normally expect. Parking in rodent-prone areas or near possible food sources (like bins or pet food) can increase the risk of rodent activity under the bonnet. We also recommended periodically inspecting the engine bay for any signs of nests or damage.

With the vehicle’s issues resolved and proper maintenance advice given, the client could drive away with peace of mind. At D & D Mechanical & 4WD, we don’t just repair cars; we deliver results that our clients can rely on.

See how D & D Mechanical & 4WD in Goolwa solved a tricky car misfire issue caused by rodent damage. Diagnostics, repairs & advice to get you back on the road.

Car Misfire Fixed & Rodent Damage Repaired in Goolwa

V6 Engine Misfire Trouble and an Unwelcome Surprise Under the Bonnet

At D & D Mechanical & 4WD in Goolwa we provide Log Book Service that protects your statutory warranty for a wide range of makes and models.

You have the right to choose a mechanic for car service. Simply book a service for your car or contact D & D Mechanical & 4WD, tell us about your car and your last service and we can give you a quote today.

D & D Mechanical & 4WD can supply log book service and more on a wide range of makes and models right here in Goolwa

Worried about your your new car warranty? You shouldn't be. As a consumer you are at liberty to establish the service centre that conducts your log book service without worrying about losing your right to a statutory warranty. You don't have to travel across town to get to a dealership or pay inflated prices. Find out more about your rights on our New Car Service page.

Contact D & D Mechanical & 4WD for all car servicing and mechanical repairs you may need. Visit our Goolwa Workshop, Call us during business hours or use our easy online booking form below.

Makes & Models D & D Mechanical & 4WD service, Log book service, log book servicing, hand book service, new car warranty service, Goolwa

Makes & Models we service in Goolwa

A vehicle was dropped off to us and the owner noted that is was down in power, but using heaps more fuel, client also noted the check engine light was illuminated ???

After receiving authorisation to commence a Test/ Diagnostic Service, we connected our scan tool & checked the fault codes logged. We located an EGR valve fault code and a turbo boost issue. Upon clearing these codes we road tested and rechecked diagnostic trouble codes. Unfortunately, the EGR valve fault code had relogged but the turbo boost fault did not re log as a fault code, at this stage.

As we identified a possible EGR valve fault, we liaised with client advising valve needed to be removed & have static testing completed to verify fault. After dismantling the EGR valve from the intake manifold & performing a static operational test, all checks appear OK.

Next step was to reinspect vehicle. During EGR valve removal it was noted that there was extensive carbon build up inside the manifold runners which could be potentially causing flow issues in the intake manifold and possible EGR anomalies. We spoke again with our client & advised the EGR Valve was operationally OK and that an expensive component was not required for replacement Client was relieved! 

Our next step was to dismantle & clean the intake manifold. This repair was complete, vehicle was reassembled & road tested. There was instant power gain and no relog of fault codes or check engine light on. We kept the vehicle overnight for cold start checks/ running, all checks appear OK, clients vehicle was released and has been running for 10 days trouble free....another satisfied customer of D & D Mechanical & 4WD

D & D Mechanical & 4WD share a recent Vehicle Diagnostic Repair job that a client brought to them, which was down in power, using a lot more fuel and the check engine light was on...

Loss of power & increased fuel use - What could be the issue?

D & D Mechanical & 4WD in Goolwa is able to perform roadworthy/ safety inspections

A roadworthy inspection includes checking:

A roadworthy/ safety inspection is not a comprehensive full vehicle inspection. Talk to us today about the different types of inspections available at D & D Mechanical & 4WD and which one will best suit your needs. 

A roadworthy / safety inspection is not a comprehensive full vehicle inspection. Talk to us today about the different types of inspections available at D & D Mechanical & 4WD and which one will best suit your needs.

Roadworthy / Safety Inspections in Goolwa

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The team at D & D Mechanical & 4WD will meet all your car service and repair needs here in the Southern Fleurieu. 

Based in Goolwa, on the Fleurieu Peninsula, they take great pride in offering their clients personalised, and friendly service at all times. This business is a member of the Repco Auto-Tech training program, ensuring their technicians are kept fully up to date with modern vehicle repair methods. 

D&D Mechanical & 4WD have a wealth of experience in servicing all makes and models. As a Repco Authorised Service centre, they have a commitment to high quality workmanship, ensuring the very best in automotive care, & with an Industry Leading Satisfaction Guarantee you know you are with the best hands in the business.

D & D Mechanical & 4WD

Roadworthy / Safety Inspections

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V6 Engine Misfire Trouble and an Unwelcome Surprise Under the Bonnet

Car Makes and Models we can Service

Loss of power & increased fuel use - What could be the issue?