Why does my 1997-1998 Volvo S90 or V90 lurch, start hard or blow cold?

Short answer: On a 1997-1998 S90 or V90, a high idle that makes the car lurch points to the idle valve or an air leak. Hard starts that need gas were fixed by a MAF sensor in one owner's case. Cold heat at highway speed is usually the thermostat, and oil out of the dipstick means checking the PCV hoses.

Symptom: The idle races and the car lurches, it starts only with gas, the heat goes cold on the highway, or oil pushes out the dipstick.

What to check first

1. Check for air leaks and clean the idle valve.
2. Test or swap the MAF sensor.
3. Check the thermostat.
4. Clean the PCV hoses and do a compression test.

Likely causes

1. Idle air control valve or air leak. High idle that makes the car lurch with your foot on the brake often comes from a stuck idle valve or air leak.
2. Mass airflow sensor. The MAF sensor measures air going in. If it fails, the engine may only start with gas pedal help.
3. Stuck-open thermostat. The engine never warms up at speed in winter, so the heater blows cold.
4. Clogged PCV hoses. Plugged crankcase vent hoses push oil out the dipstick tube and cause smoke.

What it usually costs

One owner bought a MAF sensor for about $25 on eBay after a $140 quote. Other prices weren't posted.

Is it safe to keep driving?

Lurching at stops is dangerous. Fix it before driving. Oil smoke may mean a fire risk if oil hits hot parts.

DIY or shop?

Most of these are DIY with basic tools.

Recalls, bulletins and complaints in plain words

• Recalls: NHTSA's recall lookup returned no data for the Volvo S90 for 2 model-year queries on 2026-10-28, so we couldn't confirm recalls here. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 3 keyword-matched complaints for Volvo S90 1997–1998 (of 54 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-28; keywords: idle, stall, lurch, start, heat, oil, smoke, pcv, maf, surge) (NHTSA returned no data for 2 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In Volvo V90 Lurching and Stalling- Please Help! on Car Talk, a V90 revved and lurched with the driver's foot on the brake. Members pointed to the idle air control valve and an air leak.
• In Volvo s90 press gas pedal to start on Car Talk, a 1998 S90 needed gas to start after running out of fuel. The owner fixed it with a new MAF sensor, about $25 on eBay versus a $140 quote.
• In 98 Volvo S90 heat blows cold in winter on Car Talk, a 1998 S90's heater went cold at highway speed in winter. Members suspected the thermostat.
• In 1998 volvo s90 oil issues on Car Talk, a 1998 S90 pushed oil from the dipstick and smoked. Members said to clean the PCV hoses and do a compression test.

Quick tip

Old Volvos reward cleaning the PCV system. It solves more than you'd think.

Vehicle focus: Volvo S90 and V90, 1997-1998 (rear-wheel drive).

Safety / mechanic note

Lurching and oil leaks are safety items. Verify with a mechanic.