KA24E Motor vibration problem whem warmed

[thekawaii]

Car runs smoothly when engine is cold. Idle smooth also.

But when engine gets hot, it vibrates at idle.

Checked the Injector connections, they were all okay. I don't think it's an injection problem...

I think it might be a ****ed up hydraulic lifter since it also makes noice when engine warms up.

Any Idea?

[TDS]

Does your idle also fluctuate when warm? If it does then you may have a vacuum leak.

My engine and idle would be stable at cold starts. Once the engine warmed up, the idle would fluctuate (+/-50to100+ rpms) and the engine would shake. I Got rid of the leak and everything is smooth. I think the lifters tend to get noisy regardless unless its ridiculously loud.

[thekawaii]

It does little bit.

Which vacuum line was leaking on your engine?

[TDS]

I ended up taking out all emissions but before this, i found a leak between the throttle body and Coolant Temperature sensor. You will see three hard lines that run parallel to the intake manifold and fuel rail. They connect to 3 hoses that lead to aiv and charcoal canister. The rubber vac line to one of those lines was unplugged. Another leak was found behind the head. if you look behind your valve cover and by the firewall, you'll see two sensors attached to a bracket and tons of small vac lines looping to hardlines. I found one of those lines unplugged too.

I'm not saying you will absolutely find leaks here, but those two areas you should look over carefully because they are not easy to see.

[hypertek_sideview]

i noticed once mine is warm i notice suttle changes in idle (estimating 5-20rpm) but the motor does small shakes. I don't hear a change in idle tone but I figure its the motor fluctuating. Aside from needing engine mounts(already on order) what else could be done to possibly smoothe out the idle. (same motor sohc).