Thread: Shut off valve
View Single Post
  #9  
Old 07-26-2021, 01:53 PM
Alec300SD Alec300SD is online now
Registered User
 
Join Date: Nov 2013
Location: San Mateo, CA
Posts: 1,163
Quote:
Originally Posted by dsvw View Post
My 1986 190D stays on for about 4 seconds after I turn the engine off.

Any ideas?

Thanks!
You most likely have a low level leak from one or more rubber connecters somewhere in the vacuum circuit.

The ones in the engine bay tend to fail first.
The connectors should really grip the hard vacuum lines tightly, and be difficult to remove.
If they are loose, replace them.

Isolate the shutdown circuit by plugging off the other vacuum consumers (HVAC, etc.) with golf tees.

If it shuts down quickly, then the leak is in one of the temporarily disabled circuits.

If it is still slow to shut down, then you have a leak in the shut down circuit.
A hard line might have a crack, the rubber connectors at the vacuum valve may need replacing, or the shutoff valve on the ignition switch may be sticking.
__________________
78 W116 300SD 'Desert Rose' new as of 01/26/2014
79 W116 300SD 'Stormcloud' RIP 04/11/2022
Reply With Quote