2005 Pontiac Montana Problems: 1 Issues Every Owner Should Know
2005 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated May 2026
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2005 Pontiac Montana has 1 documented known issues, with 1 rated critical. The most serious is Montana 3.4L V6 Intake Gasket — Same as Grand Am ($500-$1,200 repair). Across all issues, repair costs range from $500 to $1,200. DIY maintenance guides at au7o.io.
All 1 Known Issues
On the 1999-2005 Pontiac Montana 3.4L LA1 V6, same 3.4L LA1 V6 upper/lower intake gasket failure as Grand Am. The U-body minivans (Pontiac Montana, Chevy Venture, Olds Silhouette) all share the engine and the failure pattern. Often presents earlier on the minivans due to higher load duty cycles.
Common Symptoms
- coolant under intake
- coolant loss
- milky oil
- rough idle
- overheating
How to Fix
Same fix — updated Fel-Pro MS98010T LIM gasket + UIM gasket + plenum repair/replacement. $500-$1,000 at independent (minivan labor slightly higher due to packaging). Drain Dex-Cool, refill with Zerex G-05.