MAHLE C31900 COOLANT THERMOSTAT HOUSING GASKET FOR 01–16 GM DURAMAX

Product Description

Stop seepage at the coolant outlet and keep temps in check with the MAHLE C31900 thermostat housing gasket for 2001–2016 GM 6.6L Duramax (LB7/LLY/LBZ/LMM/LML). OE-style construction delivers a precise seal between the thermostat housing and cylinder head to prevent leaks, overheating, and downtime.

Mahle C31900 thermostat housing gasket, Duramax coolant outlet gasket, 6.6L GM LB7 LLY LBZ LMM LML gasket, Mahle Duramax cooling system seal, CPP Diesel Mahle C31900

Fitment

• 2001–2004 Chevrolet/GMC 2500HD/3500HD – 6.6L Duramax LB7
• 2004.5–2005 Chevrolet/GMC 2500HD/3500HD – 6.6L Duramax LLY
• 2006–2007 Chevrolet/GMC 2500HD/3500HD – 6.6L Duramax LBZ
• 2007.5–2010 Chevrolet/GMC 2500HD/3500HD – 6.6L Duramax LMM
• 2011–2016 Chevrolet/GMC 2500HD/3500HD – 6.6L Duramax LML

Cross-Reference / Alternatives (Mahle on CPP Diesel only)

• MAHLE C33755 – Coolant Water Bypass Gasket (2017–2020 L5P)
• MAHLE GS34005 – Engine Oil Cooler Gasket Set (2001–2016)
• MAHLE MS19398 – Exhaust Manifold Gasket Set (2001–2016)

Notes

Clean mating surfaces thoroughly and inspect for warpage. Install dry unless OEM procedure specifies otherwise. Torque fasteners to factory spec. Consider replacing thermostats during service if mileage is unknown.

FAQ

Will this fit all 2001–2016 Duramax engines?

Yes—C31900 covers LB7, LLY, LBZ, LMM, and LML applications (2001–2016).

What does this gasket seal?

It seals the thermostat housing (coolant outlet) to the cylinder head to prevent coolant leaks.

How many do I need?

Typically one at the thermostat housing location; verify your repair procedure.

Specifications for Mahle C31900