Every engine is different, but they’re all pretty similar. You’ll need to remove the intake manifold from the old engine before installing it on the new one. This is the perfect time to do some deep cleaning. You’ll need a new gasket in most cases (better safe than sorry), and you should convince your customer to go ahead and buy a new EGR valve and gasket just to be on the safe side. Manifolds with throttle body injection MUST have the TB (throttle body) removed during cleaning. Often times debris will lodge itself immediately under the TB!

Flip the intake manifold over to see where the carbon buildup is. Remove the gasket if it’s stuck to the bottom of the intake. Check out the amount of carbon or debris damage on the intake so you know the likely places where extra effort will be required. If there’s a serious amount of buildup (i.e. you’ve only got a narrow hole in the intake free of carbon), it might be best to just buy a new one.

Some mechanics prefer to use a pressure washer to remove some carbon immediately, and then soak it, while others prefer to soak it immediately. Either way, the point of the job is to remove all the carbon or debris from the intake so that none of it gets sucked into the new engine after installation. Most often, any debris left behind by your original engine failure will be embedded in the carbon. Take the intake and soak it in a chemical bath – depending on your shop’s setup, this might be carb cleaner or a specialty chemical mixture. Regardless, let it soak as long as necessary. For normal amounts of carbon, this might be most of the day, but for severe buildup, let the intake soak overnight in the bath.

After bathing, wash the carbon out using high-pressure water. Once you’ve cleaned out the carbon, visually inspect the intake once more. You’re looking for any carbon or debris deposits that weren’t removed by the water. You should remove these to avoid potential damage to the new engine – blow the intake out thoroughly with high-pressure air. Once all the carbon has been removed (and you’ve THOROUGHLY inspected the intake), it can be installed on the new engine.

If your customer isn’t replacing the EGR valve, you’ll need to clean the carbon out of it as well. They’re not very expensive though, so it’s really better just to bite the bullet and put a new valve on just to save time and headaches.

Take these steps and you’ll ensure to avoid this common engine installation error.