Sonoma's Rough Idle Signals Intake Manifold Trouble

Had a similar situation with my GMC Canyon (2014 diesel) that turned out to be a failing intake manifold. The symptoms match exactly, rough idle, engine misfires, and drop in power under acceleration. The vacuum leak from the cracked manifold was causing unmetered air to enter the system, throwing off the air-fuel mixture. The engine misfire occurred because the manifold sensor was getting incorrect readings due to the leak. A smoke test confirmed multiple cracks around the manifold gasket seals. This was a serious issue requiring immediate attention, as continued operation could lead to further engine damage and increased emissions. The repair involved replacing the entire intake manifold assembly since the cracks had spread too far for a simple gasket replacement. The manifold sensor and several vacuum lines also needed replacement due to heat damage. When dealing with intake manifold issues, its crucial to address them quickly. The symptoms typically worsen over time and can lead to catalytic converter damage if left unchecked. A qualified technician needs to perform proper diagnostic tests, including vacuum leak detection and manifold pressure testing, to confirm the exact issue.

Thanks for sharing your experience. It sounds exactly like what I am going through with my Sonoma. I went ahead and had it fixed last month after the check engine light came on and those nasty misfires got worse. The mechanic found a major gasket leak around the intake manifold area, causing all sorts of vacuum problems. How much did your repair set you back? Just wondering if I got a fair price. Also curious if you have had any other issues pop up since getting the manifold pressure problem sorted? The car runs great now but I want to stay ahead of any potential related problems.

Thanks for the follow-up. Good to hear you got it fixed, these air intake issues can really cause havoc if left unchecked. After getting my manifold replaced last year, I paid 1180 Euro for the complete fix, including parts and labor. The work involved replacing the defective intake manifold and dealing with some scorching damage that had occurred around the gasket area. The price seemed reasonable given the extent of the work needed. The car has been running perfectly since the repair. The rough idle and manifold pressure problems completely disappeared once the new unit was installed. Just keep an eye on your engine performance and manifold sensor readings through regular maintenance checks, proper air-fuel mixture is crucial for these engines. One tip: make sure to address any check engine lights promptly if they show up again. A small gasket leak can quickly escalate into bigger problems if not caught early. But honestly, with a proper repair job like you had done, you should be good for many miles to come.

I ended up taking my Sonoma to another mechanic after getting your feedback. The symptom match was too close to ignore. Turned out you were spot on, they found a significant gasket leak at the intake manifold causing those vacuum issues. The full repair came to 1450 Euro, including a new manifold assembly, sensors, and labor. They also had to clean up some carbon buildup that had formed due to the leak. After two months, the car runs like new again. No more engine misfires or rough idle problems. The exhaust smell is completely gone too. Really glad I got this fixed when I did. The mechanic mentioned the manifold gasket leak was pretty severe and could have caused more expensive engine damage if left any longer.