When I start my van it starts at high idle, it lowers a little then goes back up. It stays at a very high idle while driving. I can take my foot of the accelerator at 45 mph and it'll stay at that speed and sometimes climbs. When the problem first started it would correct it self after driving 15 or so minutes. Now its always at a high idle. Ive start to turn the vehicle off while its still in gear to prevent the transmission from slamming into park. I've recently replaced the EGR valve, throttle position sensor and mass air flow sensor.
My car has 192000 miles.
My car has an automatic transmission.
Hello. There are a lot of reasons that would cause a high idle, but most of the time it is caused by a vacuum leak. When there is an excessive amount of air entering the engine the computer will compensate with more fuel causing a higher idle. Most of the time the issue is in the intake manifold gasket. I would typically start by checking the engine sensor readings with a scan tool and then check for vacuum leaks with either propane enrichment or by performing a smoke test. If you need to have this idle issue repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose this high idle problem] https://www.yourmechanic.com/services/engine-idle-speed-is-high-inspection
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