High Idle only after engine has completely cooled down

Tiny
JAMMIE64
  • MEMBER
  • 2003 CHEVROLET IMPALA
  • 3.4L
  • V6
  • 2WD
  • AUTOMATIC
  • 113,000 MILES
I start it drive 25 minutes to work and it's fine. After it sits all day it's fine.
If I go out and restart it before the engine completely cools down, it will idle way too high. Seems to be heat related. I replaced much of the cooling system last year (head and lower gaskets, radiator, water pump) as it ran hot. That problem solved now this high rpm. Perhaps it's a vacuum leak? I might have put the hoses back on wrong after disassembly. Any ideas? Hose diagram or photo of another 3.4 might help? Thanks!
Thursday, June 25th, 2020 AT 1:45 PM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,645 POSTS
Hi,

I attached two pics for you to review. They are the vacuum routing schematics. Let me know if they help. Also, here is a link that explains how to check for a vacuum leak:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Let me know what you find.

Joe
Was this
answer
helpful?
Yes
No
Thursday, June 25th, 2020 AT 7:29 PM

Please login or register to post a reply.

Sponsored links