Q: if i wanted to remove the intake manifold because i have a vacuum leak; would i have to remove the fuel rail

asked by on June 17, 2017

If i wanted to remove the intake manifold because I have a vacuum leak; would i have to remove the fuel rail? The reason I want to remove it is because I hear a hissing sound coming from it and the engine keeps idleing really bad and bogs down under 500 rpm when i come to a stop.

My car has 174000 miles.
My car has an automatic transmission.

Intake Manifold Gaskets Replacement $166.06 - $992.76 Get a Quote

You should first confirm the vacuum leak by carefully introducing propane (or equivalent) at the suspected leak site. If introducing propane at the leak site increases engine speed, then you have a vacuum leak. Perform the test outdoors and be careful about other ignition sources.


The fuel rail of course has to be disconnected from the supply and return lines. During an operation like that you are performing, the best practice is to remove all injectors from the fuel rail and mail them to a lab such as Mr. Injector. They will replace the miniature internal filter in each injector, clean the injectors ultrasonically and test them and supply you with a report. Regarding your question, you ONLY have to remove the fuel rail if the rail blocks access to the intake manifold bolts. If the bolts are accessible with the rail in place, and in particular accessible to a calibrated torque wrench on re-installation, then you do not have to remove the fuel rail. As noted though, strictly speaking it’s a moot issue, as the best way to do the job is have the injectors professionally cleaned while you have the intake off.


If you desire assistance on this project, simply request intake manifold gasket service and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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