VW Caddy Engine Light On: Rough Idle & RPM Problems

Had a similar issue on my 2007 VW Golf with the 1.6L gasoline engine. With some basic car maintenance experience, I first thought it was the throttle body causing the unstable idle. After taking it to the workshop, they diagnosed the actual problem: a damaged vacuum hose connecting the fuel pump to the air valve. The erratic idle and check engine light were caused by inconsistent air pressure in the intake system. These symptoms got worse with heat because the damaged hose would expand more when warm. The repair involved: Complete system pressure test, Replacement of the defective vacuum hoses, Cleaning the air intake system, Reset of engine management system Total cost was 175€ including parts and labor. The idle problems disappeared completely after the fix. Could be facing something similar with your Caddy, but would need more details: Current mileage? Any specific error codes from the check engine light? Have you noticed any unusual sounds from the engine bay? When was the last throttle body cleaning done? These details would help determine if your issue matches what I experienced.

Last service was at 143000km and currently showing 146095km. Actually got it diagnosed today and you were right, it was indeed a vacuum leak. The mechanic found cracks in the intake hose near where it connects to the throttle body. The damaged hose was causing unstable air intake readings, which explained the erratic idle behavior. Engine stalling would happen particularly after the engine got hot, just like you described. The repair bill ended up being 220€ including a full air intake system inspection and cleaning along with the hose replacement. The car runs smoothly now with stable idle. No more check engine light either. Thanks for sharing your experience, it helped me understand what I was dealing with before heading to the shop.

Really glad to hear you got it sorted out and that my similar experience helped point you in the right direction. The symptoms matched almost exactly what I encountered, especially that characteristic warm engine stalling due to the vacuum leak getting worse with heat. The repair cost seems reasonable at 220€, considering they did a complete intake system cleaning along with replacing the vacuum hoses. This kind of preventive maintenance can help avoid future air supply issues. On my Golf, after the repair, I made it a habit to visually inspect the vacuum hoses every few months for any signs of cracking or wear. These rubber components tend to deteriorate over time, especially in the high-heat environment of the engine bay. Been running perfectly for 2 years now without any idle problems or check engine warnings. One tip: if you notice any slight roughness in idle in the future, get those vacuum hoses checked right away. Early detection of leaks can prevent more extensive damage to the air intake system.

Thanks for the excellent follow-up information about solving your vacuum leak issue. The repair details and cost breakdown will definitely help others with similar manifold pressure problems. The mechanic seems to have done a thorough job checking the entire air intake system during the repair. My next service is coming up at 150000km, so I will definitely have them inspect all the vacuum hoses and throttle body components as a preventive measure. Those deteriorating rubber hoses can be tricky, mine looked fine visually but the cracks only showed up under pressure testing. The unstable idle and check engine warnings were definitely worth getting checked out. Much better to catch these issues early before they cause more extensive engine damage. Really appreciate the advice about regular vacuum hose inspections. Will make that part of my routine maintenance checks from now on. The car is running great after the fix, smooth idle and no warning lights. Money well spent on proper diagnosis and repair.