The upper intake manifold cracked, which caused coolant to leak onto the engine. The dealer stated the problem occurred due to the plastic manifold not being able to withstand engine heat temperatures.

- High Point, NC, USA

The original and the replacement upper intake manifold malfunctioned. Mr scc

- Champaign, IL, USA

There were problems with the intake manifold. * mr the vehicle failed to start due to the coolant leaking into the cylinders. The consumer then received a bulletin which was in reference to the intake manifold/coolant consumption leak. Scc

- Scotch Plains, NJ, USA

The consumer couldn't get the vehicle started. The consumer tried to get the vehicle started again and heard a loud noise which was followed by a fire under the hood. Referenced in EA02-030

- Roopville, GA, USA

Plastic manifold melted causing coolant to flow into the piston chamber. This seems to be a major malfunction with this part and should be brought to GM's attention to be recalled with a better solution than a plastic manifold.

- Milwaukee, WI, USA

Plastic intake manifold cracked. $1500 repair due to poor design. Engine stalled due to coolant leaking onto engine cylinders. Have done extensive research including web sites like carreview.com where over 10% of all comments on this car (good or bad) complained about intake manifold problems. Recall seems in order.

- Dover, NH, USA

Second replacement of the upper intake manifold.

- Champaign, IL, USA

1998 Pontiac bonniville they use a plastic intake manifold cover of schrowed.within this cover they have hole for the egr valve which gets very very hot, and to cool this they run coolant around this within the plastic. Don't they realize that the plastic will crack from expansion and contraction and coolant will infiltrate the intake manifold and the entire combustion chamber, exhaust. This happened to my 98 bonniville and I want this to be investigated.

- Lk Grove, NY, USA

Please see the attached complaint

- Metmora, IL, USA

While in motion, the engine died causing a pile up on the highway. The engine manifold and the gasket caused what is called a vapor lock up. This is a continuous problem with this vehicle. The manifold and gaskets have been replaced 4 times prior.

- Metmora, IL, USA

Consumer states that while driving at any speed and no warning coolant fluid are being pump into the engine. Dealer notified

- Freeburg, IL, USA

While driving vehicle started running rough. Then, the engine stopped. Contacted dealer, valve cover gasket was leaking, and water went into engine cyclinder. This is a common problem. The mechanics removed/replaced the intake manifold, both upper and lower manifold gaskets.

- Cincinnati, OH, USA

The vehicle's intake valve covers cracked and the coolant was sucked into the cylinders causing the engine to overheat and stall.

- Egg Harbor, NJ, USA

Rod bearings for cylinders 1 and 2 failed due to lack of lubrication with recommended amount of oil in the vehicle. GMC is not interested in finding the root cause. They have insinuated that we ran the vehicle without oil but can not explain why bearings for cylinders 3-6 show no signs of lack of lubrication. GM is not offering any assistance although the vehicle is barely beyond warranty.

- Rcokford, IL, USA