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

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.

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.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. if i wanted to remove the intake manifold because i have a vacuum leak; would i have to remove the fuel rail

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Kia Optima hesitates when in gear. Does not while in park. It has slowly became worse over the course of many months. It still dr

If the transmission is not faulty (e.g., clutches slipping) and thus the problem is engine related, among the possible causes of the hesitation are faults in the throttle position sensor, mass airflow sensor, vacuum leaks, a clogged fuel filter, defective...

Q: Delayed engagement from P to D when cold, but not in reverse

Many newer automatic transmissions have temperature-sensors in them that, on a stone-cold start, restrict normal shift to only the lower (or non-overdrive gears) until the engine coolant and transmission fluid reach a certain level which in many engines, is around...

Q: RPMs max out

Hi there. If the throttle body is fully closing then this is either caused by an electrical short or a vacuum leak. If the throttle body is not fully closing then the throttle cable may be binding. I would suspect...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...