anton_stern4

Suburban Cylinder Pressure Fluctuation

I've got a 2020 Chevrolet Suburban with the Duramax diesel, and I'm chasing a cylinder pressure fluctuation issue. Mileage is sitting at 225024 km. I'm seeing higher fuel consumption, a noticeable drop in engine power, and the check engine light is on. I've scanned it, but the code points to a consequential error, rather than a root cause. I've checked the timing belt, spark plugs (though I know it's diesel), and I don't hear any engine knocking. Any ideas where to start digging?

The 2020 Chevrolet Suburban with a Duramax diesel engine is experiencing cylinder pressure fluctuation, leading to higher fuel consumption, reduced engine power, and an active check engine light. Initial checks on the timing belt and spark plugs showed no issues, and engine knocking was not present. Potential causes suggested include worn piston rings, intake manifold leaks, or blockages. A proper diagnostic check at a workshop was recommended, which revealed the issue was not related to cylinder pressure and resolved itself during the diagnostic process.

Did this summary help you solve your problem?

4 comment(s)

That's a tricky one. A consequential error usually means something else is causing the problem. Have you checked the piston rings for wear or damage? A leak there could definitely cause fluctuating cylinder pressure. Also, inspect the intake manifold for any potential leaks or blockages. How does the engine sound at idle? Any unusual noises besides the knocking you already ruled out?

Piston rings and intake manifold are next on my list. The engine sounds relatively normal at idle, perhaps a slight roughness, but nothing alarming. Could a faulty sensor be giving misleading data and causing the pressure issue indirectly?

A faulty sensor could be the culprit, but it's less likely to directly cause a fluctuation in cylinder pressure. It's more probable that the sensor is reporting the fluctuation accurately. Given the symptoms and the fact it's a consequential error code, I'd really recommend getting a proper diagnostic check at a workshop. They can do more in-depth testing than we can advise online.

Appreciate the insight. I'll take it in for a proper diagnosis. Turns out, it was a consequential error, as we suspected. The problem was not related to the cylinder pressure at all and fixed itself during the diagnostic, so the repair cost was 0€

rmh_community_comment_box_header

community_crosslink_scanner_headline

community_crosslink_scanner_intro

community_crosslink_scanner_title

community_crosslink_scanner_price

community_crosslink_rmh_headline

community_crosslink_rmh_intro

community_crosslink_rmh_title

community_crosslink_rmh_subtitle

community_crosslink_rmh_brand

CHEVROLET

community_crosslink_rmh_model

SUBURBAN