High Idle Issue on 03

Hello everyone. I have a 2003 V6. I just had it in the shop and had the valve cover and intake manifold gaskets replaced. But now when I start it up when it's cold (meaning I haven't driven it in several hours) it idles around 2K for about 5 minutes. That is way higher than it did before. It eventually comes down to slightly less than 1000 after it warms for a few moments. Any ideas on what could be causing it, or what needs to be adjusted?

 

Intake leak due to a hose not replaced correctly? Is your "check engine" light coming on (due to a lean code)?

 

No check engine light. When it warms up it's perfect. It's just for the first few minutes it runs way higher than normal.

 

Did you figure out what was causing the high idle? I have a similar issue...

 

I believe so. So I realized after replacing the valve cover gaskets that it was still leaking oil from the firewall side of the engine. I could smell it burning after the engine got hot. I friend of a friend used to be a Toyota tech as it turns out. He asked me if I had replaced or resealed the cam caps when having the valve covers changed. And that answer was no, never even heard of those. So I went to the dealer and got some new ones and another valve cover set. This time a factory valve cover set and not after market. So he ended up taking the valve covers back off, replacing the cam caps, resealing them, and putting the factory gaskets back on. No issues since then. Idle went back to normal. It was either a vacuum leak because of the cam caps needing to be resealed, or the after market valve cover gaskets didn't seal properly.

 

hmm odd behaviour. While I am not doubting the fix I am curious as to the symptom... you would think that if the idle would increase due to a slight crankcase leak because of a seepy cam plug seal then taking the oil fill cap off or pulling the oil dipstick would kill a running motor, I have only seen this symptom on turbo motors.

 

Mine is behaving the same way. I am looking for a vacuum leak.

 

The second used throttle body assembly ended up working to fix my high idle. I was doubtful since it didn't fix it with the first used "running" motor throttle body assembly that I bought on ebay. The second used one came from a big salvage yard with a 6 month no hassle return policy.

 

what mileage is on the motor. My 4 cyl did the same thing AFTER the rebuild... I guess the old motor was so worn out that the sloppy throttle body didnt make a difference... a Junk yard one solved that problem too. I could take the throttle body where the cables connect and push in and out (axially) and that would change the air gap between the throttle plate and bore just enough to make her idle high. After cleaning all the gunk off the throttle bore it got worse. All of the build up was actually closing the gap.

 

The one that worked is from a vehicle with 189k from the salvage yard. Not sure if it original. I did not clean it at all because it seemed to make a good seal with the buildup. The first two with problems I cleaned with throttle body cleaner and it left gaps without the buildup.