Removing An Intake - Replacing An Intake Gasket

Removing an engine's intake manifold and replacing it's gasket appears a daunting task at first, especially on modern front wheel drive vehicles with crowded engine compartments. At first glance there seem to be hundreds of hoses, wires and a bunch of funny looking objects covering the intake manifold. One might think that getting underneath those wires and hoses must be almost impossible. The reality is that removing an intake manifold to replace it's gasket on most vehicles is not nearly as demanding as one would think. After a few minutes of unhooking wires and hoses and moving them out of the way the intake manifold is suddenly a lot easier to get at. I've ranked it a level 6 job, but mainly because of the time involved, otherwise I would have ranked it as a level 5 project.

Bear in mind that intake manifold removal and replacement difficulty varies among different types of vehicles. Trucks and many 4 cyl. engines are generally easier to work on because they have more room in their engine compartments. Older vehicles such as classic cars and vehicles w/o emissions controls are even are a real cinch. But, when it comes down to it, the process is pretty much the same even with modern vehicles with electronic fuel injection. Be sure to read your repair manual before you begin. Follow along and we'll show you what's involved.

Our patient is a very common engine: a late eighties Chevrolet 350 V8 with throttlebody injection in a full-sized pickup.

What you need Tools: Socket set, wrenches New intake gasket   screwdrivers, pliers Drain pan for antifreeze/oil Gasket scraper or razor blade Solvent and paper towels New oil

Step 1. Remove and disconnect We began by disconnecting the battery, draining the coolant, removing air cleaner. Then we removed the upper radiator hose. There seemed to be more room already!
Step 2. Remove and disconnect II The next step was to remove the distributor cap like shown and pull the wires off to the side and get them out of our way. Then, we removed all vacuum hoses that connect to the intake manifold and throttle body.
It's a good timesaving idea to mark the vacuum hoses and plug wires with some masking tape and a permanent marker to guarantee they get reinstalled properly.
Step 3. Remove wire connectors Next, we unhooked all wire connectors that were connected to temperature sensors, the oil pressure sensor and the throttle body as you can see in the picture. You should be able to carefully flop all the wires to the side so they are out of the way. We're only about 15 minutes into the job thus far and it's amazing how much of the "clutter" we have removed already!
Step 4. Remove steel lines So far we haven't needed to get out any wrenches yet. But now it's time to remove the steel fuel and vacuum lines that go to the carburetor. Be sure to use a line wrench and the two-wrench method (see pic) so you don't round the fittings off. You can see antifreeze just below the red arrow. Our intake gasket was leaking coolant at that spot.
Step 5. Remove brackets and distributor Once the steel lines are removed, we unbolted our throttle linkage bracket, moved that out of the way, then we removed the little retaining bolt at the base of the distributor and pulled the distributor out. There were a few other minor brackets we had to remove as well.
You can save yourself a fair amount of time and grief by turning the engine over until the timing mark on the crankshaft is on the TDC mark. Then, put a mark on the distributor indicating the position of the rotor notch. That way you can just put it back in w/o having major timing problems.
Step 6. Remove manifold bolts Now we're really making progress. Now that we've removed the wires, hoses and a few brackets, all we need to do now is unbolt the manifold itself. There are about a half a dozen bolts on each side that need to be removed. They're easy to get to.
Manifold studs are often different lengths, and some have studs on the ends, while others don't. You can save yourself some guess work and installation time if you keep them straight. Set them on your work bench in the order you remove them. Then replace in the exact same order.
Step 7. Remove intake manifold Once the bolts were removed, we gently pried up on one corner of the intake manifold to unseat it, then lifted it off the motor.

Continued