# Dieseling on 1985 MB 300CD **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** diesel, mercedes-benz, engines\ **Created:** [February 16, 2010, 2:59am UTC](https://community.cartalk.com/t/dieseling-on-1985-mb-300cd/44573 "2010-02-16T02:59:26Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![jaslesinger](https://avatars.discourse-cdn.com/v4/letter/j/b5ac83/32.png) [@jaslesinger](https://community.cartalk.com/u/jaslesinger)\ **Post date:** [February 16, 2010, 2:59am UTC](https://community.cartalk.com/t/dieseling-on-1985-mb-300cd/44573/1 "2010-02-16T02:59:26Z")
Engine continues to run at idle when switched off with key. Engine stops only after pressing Engine Stop button under hood. 1. What are possible causes/solutions? 2. Could a remote button inside car be rigged to actuate Engine Stop button under hood? ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [February 16, 2010, 3:03am UTC](https://community.cartalk.com/t/dieseling-on-1985-mb-300cd/44573/2 "2010-02-16T03:03:45Z")
When you turn off the key, a “stop engine solenoid” is supposed to perform the same function. Not a major repair on these cars, any Benz shop can do it without breaking the bank… ---
**Author:** ![Baxter\_s\_Dad](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/baxter_s_dad/32/27_2.png) [@Baxter\_s\_Dad](https://community.cartalk.com/u/Baxter_s_Dad)\ **Post date:** [February 16, 2010, 4:48am UTC](https://community.cartalk.com/t/dieseling-on-1985-mb-300cd/44573/3 "2010-02-16T04:48:09Z")
The shutoff is vacuum operated (No Solenoids!)and can be caused by something as cheap as a vacuum line knocked off. If the oil filter has been recently changed that is the likely culprit. The oil filter is mounted on the firewall drivers side. Look there for any vacuum lines off. Otherwise it’s leaky valve in the vacuum pump. Cheap and easy DIY repair.