Said It Here

How do you drain oil out of an intercooler?

Intercoolers and charge air coolers frequently accumulate pooled oil and oily water that cannot be reached with standard vacuum pumps due to kinks in the boost pipes. This trapped fluid can freeze in cold weather and disrupt normal vehicle operation, such as preventing the car from shifting into higher gears.

Overview
People affected2 accounts across 1 forum
Workarounds found4 items attempted
Community agreement3 total upvotes

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

Found another way around this?

Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.

  1. 1
    Attempting to thread a vacuum pump through the boost sensor hole
    Did this help you?
  2. 2
    Removing the front bumper to physically access and remove the intercooler
    Did this help you?
  3. 3
    Using a mixture of Simple Green and water to slosh around inside, followed by water rinses and isopropyl alcohol.
    Did this help you?
  4. 4
    Using Purple Power HD for degreasing and a final rinse with distilled water.
    Did this help you?
Tried another approach not listed above?+ Share your workaround ↑

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/MechanicAdvice2 people · September 2026

“I can't get to the intercooler to drain it, and I've tried threading a vacuum pump through the boost sensor hole but it can't make it past the kinks in the boost pipe”source ↗

uglier_than_thou · r/MechanicAdvice · 1 upvotes

“Installing a catch can on my Chevy Cruze so I’m thinking it’s probably a good idea to remove the charge air cooler and clean it out.”source ↗

Afraid-Crab8419 · r/MechanicAdvice · 1 upvotes

“On 2nd gen Chevy Cruzes it’s pretty common for the charge air cooler to be full of oily water. The last 2 winters I’ve had no 6th gear for months as it freezes up inside and doesn’t let the car shift into 6th gear to keep rpm’s higher.”source ↗

Afraid-Crab8419 · r/MechanicAdvice · 1 upvotes

Where this came up

People with this problem also raised