Engine complaints by model year
Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
What owners report
With respect to my 1999 Pontiac transport van, October of 2003 the engine started overheating and we discovered that the coolant was low. We added coolant and some type of seal into the coolant because we were told by several GM mechanics that it was probably the head gasket and this seal would help to get us by until we could have it fixed. I called the company where I purchased the van (2nd hand) and the van was no longer under warranty (over by 4,000 miles at the time). I did purchase the extended warranty. We priced around for the cost to have the head gasket repaired/replaced and found that we would have to spend between $800 and $1,000 to get it fixed. Our van is now sitting in a garage being torn apart and the head gasket was the problem. Prior to October 2003 we had the coils changed and the #5 plug was showing a malfunctioning problem which was showing up on the computer. …
Transmission failure caused by antifreeze in transmission. Corrosion of radiator causing antifreeze to mix with transmission fluid. Now is overheating caused by intake manifold gasket leaking allowing antifreeze to get into crankcase. Potentially fatal for engine.
A well maintained 1998 Pontiac transport with a 3.4 liter engine developed a coolant leak. This was diagnosed by a local service center. As they explained that my vehicle has an intake manifold leak, it was also mentioned that they have seen many manifold coolant leaks with this engine. I decided to have it repaired at a GM dealer where I purchased the vehicle. They also explained that they service many of these type of leaks. They explained that the repair calls for a new type of manifold gasket and new bolts. The mechanic even showed me where on the old gasket the failure usually occurs. Although it May seem as if these comments where anecdotal, it still appears to point to a general failure in the design of the manifold gasket. This repair was very expensive. Why haven't these 3.4 liter been recalled? Are only inexpensive manufacturer defects recalled? …
Diagnosed with intake manifold gasket failure on 1998 Pontiac Trans Sport with 3.4 v6 engine. Oil and antifreeze mixed and fixed by dealer at cost of $890. With no assistance from general motors. All to common problems on this engine and the 3.1 v6 with speculation that the dexcool antifreeze deteriates gasket. Could possibly be true since gasket is now made out of a diffrent material. At this time it is imperative that NHTSA forces general motors to recall these engines and reimburse all owners who have paid out of pocket for repairs. This vehicle in question was well maintained and items were changed way above recommended service schedule. Vehicle also developed a rough idle with no obvious cause with possible explanation of internal engine damage. These intake gasket failures could be the reason for numerous engine fires witnessed on the highway. Also I am the original owner. …
My wife and I are the original owners of a 1997 Pontiac transport with 71,000 miles. Since about 65,000 miles, it seemed to very slowly lose coolant, but we could not find out where it was going. At 70,000 miles, a "white milky sludge like jelly material" appeared in the engine, and right away I knew we had a problem. This vehicle has been meticulous maintained, so immediately I took it to our local Pontiac dealer and informed them that we had coolant leak. The service department at the dealer confirmed that the lower intake manifold gasket had failed, allowing coolant to mix in with the oil. They had to replace the gasket and flush out the motor all to the tune of $731.00. Calling GM customer service was a waste of time because they "denied" any problems, and they said since the vehicle was out of warranty, we were responsible for any repairs. …
I noticed the low coolant light would go on sometimes and the vehicle was going through coolant much faster than any other vehicle I have owned. I performed some research on this issue and discovered a service bulletin regarding the faulty intake manifold gasket in model year 1997 transport vans, among others. This service bulletin clearly indicates that this issue a result of a poorly designed gasket. Further research indicated that having this problem with your vehicle could result in catastrophic engine failure due to the leaking coolant getting into your engine. This now creates a safety issue due to the unpredictability of when your vehicle could breakdown. I took the van in to a GM dealer the next day. The diagnosis was a faulty intake manifold gasket that was causing coolant to leak inside the engine. …
Vehicle started eating coolant, within 4 days of coolant leak head gasket had complete failure dumping contents of radiator into oil pan. Upon exam found that dextrol coolant had turned corrosive and eaten threw gasket causing failure. Replace all top end gaskets and rebuild top end. Pray that lower end will be OK once flushed completely. Have kept old parts for further exam.
Intake manifold & gasket failure - oil & coolant mixing in engine compartment - imminent engine failure front wiper motor/transmission intermitent failure while driving - difficulty diagnosing problem - major safety issue when the wipers suddenly stop/start working while driving in rain & snow or sloppy highway conditions compressor clutch hub & pulley failure
Frequently asked questions
Which Pontiac Trans Sport years have engine problems?
By NHTSA complaints, the 1998 (52), 1997 (42), 1995 (17), 1996 (13) and 1999 (5) model years. Engine complaints make up 23% of all complaints for the 1998.
Is there a recall for Pontiac Trans Sport engine problems?
No. NHTSA lists no engine & cooling recall for any Pontiac Trans Sport model year. A widespread problem may still be covered by an extended warranty or a manufacturer service bulletin, so ask a dealer.
At what mileage do Pontiac Trans Sport engine problems start?
Across all years, half of the complaints with a recorded mileage happened before about 72,000 miles; 13% happened before 50,000 miles.
What part fails most often?
Owners most often name the cooling system (32 mentions), followed by the engine (28).
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.