Why is my Chevy Venture leaking coolant?

Short answer: The 3.4L V6 in the Venture is known for lower intake manifold gasket failure. The original gaskets break down and leak coolant outside or into the oil. GM released a revised gasket kit. Fix it as soon as you see the signs, because coolant in the oil ruins engines.

Symptom: Coolant level drops, you smell coolant, see white or tan sludge under the oil cap, or the engine overheats.

What to check first

1. Look under the oil cap for white sludge.
2. Check the oil dipstick for a milky look.
3. Pressure-test the cooling system.
4. Ask for the revised GM gasket kit and new bolts.

Likely causes

1. Failed lower intake manifold gaskets. The well-known cause.
2. Hose or water pump leak.

What it usually costs

One owner was quoted $1,300–$1,400 at a dealer including a coolant flush; members said $800–$1,000 and about 6 hours of labor is more normal.

Is it safe to keep driving?

Only short trips with a watched gauge if it's a slow outside leak. If the oil is contaminated, stop and change the oil after the repair. Verify with a mechanic.

DIY or shop?

DIY for experienced home mechanics. Otherwise a shop.

Recalls, bulletins and complaints in plain words

• GM bulletin: An owner listed parts from a GM bulletin: revised gasket kit 89017279 and new bolts. A bulletin is repair guidance, not a recall.
• Recalls: NHTSA lists no recall for coolant leaks or the intake on the Chevrolet Venture for these model years (checked 2026-10-22). Other recalls may exist for your car, so check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• NHTSA complaints: 436 keyword-matched complaints for Chevrolet Venture 1997–2005 (of 2,419 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-22; keywords: intake, gasket, coolant, antifreeze, overheat, milky). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 2002 Chevy Venture coolant leak on the Car Talk community, an owner at 105,000 miles had the lower intake gasket fail. They were quoted $1,300–$1,400; members said $800–$1,000 is more normal.
• In Chevy Venture 2000 intake manifold gasket: my turn on MotorsForum, an owner at 55,000 miles found white sludge on the oil cap and listed the revised gasket kit 89017279 and bolts.

Quick tip

If you see white sludge under the cap, don't wait. This repair is far cheaper than an engine.

Vehicle focus: 1997–2005 Chevrolet Venture with the 3.4L V6. Pontiac Montana and Oldsmobile Silhouette share it.

Safety / mechanic note

Coolant in the oil can destroy an engine, and overheating can warp heads. Verify with a mechanic.