Intake manifold replacement DONE

After church, lunch, Wal Mart, and AutoZone, I restarted work at around 4:00 PM Sunday.

It turns out that I had to remove every pushrod to insert the new gasket:

Here are the pushrods and the roller rocker assemblies are sitting in roller brush paint pans by the car:

On the pans I wrote whether they came from the front or rear and also noted L and R. All the pushrods seemed to be somewhat differently sized.

By the way, the old gasket was broken around the rear water ports:

You should not be able to see those small slivers of my driveway through the gasket. (I need to learn to take pictures in front of a better background…and get a better camera!!)

New gaskets are installed and end rails buttered up with “sensor safe” high temp RTV:

If you look carefully at the right side of the block, you will see a round opening. That is a port for a distributor. My car has no distributor. Spark is completely controlled by magical computer stuff, and I have three coil packs. This car has an interesting device to block off the port:

This is really the bottom half of a distributor! It has the gear that is turned by the camshaft, and it fits over a hex rod to presumably turn the oil pump. This engine is a great example of old junk engines that work fantastically with modern fuel and spark management systems. Notice the new O-ring from AutoZone. It’s probably not the “dealer correct” part, but I’m sure it’ll do.

By the way, the hex rod is a drastic improvement over my Nova’s distributor. On the bottom of the Nova’s distributor is a fitting that only meshes with the oil pump once every 180 degrees. The hex bit will work once every 60 degrees, and it’s much more likely that the hex bit will fudge itself into position than with my Nova’s fitting.

Here’s that piece in the block with its own distributor hold down clip.

Fast forward to 12:30 AM, and the engine is complete:

Yay! Two solid days of work finally done!!

I started the car up, and the only apparent problem is that the idle seemed rough. The SERVICE ENGINE SOON light blinked. This means that the engine needs service soon to prevent damage. I shut it off and fiddled with stuff, and I think the #2 spark plug wire was loose. I unplugged and re-seated all 6 spark plug wires. It ran great after I started it up. The SERVICE ENGINE SOON light was on again, but it wasn’t blinking. It was late, so I didn’t run the engine for long or drive anywhere, but I think the SES light may shut itself off after several seconds of running provided that something else isn’t wrong.

So after around 19 hours of work, I am probably done with this intake manifold gasket replacement. Man, this is one job I hope to never repeat. The nice thing is that if I ever do it again, I can probably get it done in a day.

UPDATE: The SES light was a hoax. Someone helped me clear out a code on the car’s comptuer the next day, and the light never came on again. All I can guess is that the computer got flummoxed by all its sensors being disconnected and moved over the past two days.

Replacing the intake manifold gaskets on my Monte Carlo’s 3.1L engine

I am replacing the intake manifold gaskets on my wife’s ’97 Monte Carlo’s 3.1L. This is by far the most intricate and tedious job I have ever done. I cannot believe how interconnected everything is on this engine!

To do this job, I’ve had to remove a ton of wires and vacuum tubes, miscellaneous electrical parts, two different coolant hoses, the alternator, the power steering pump (not complete removal; just had to move it thankfully), the entire fuel injection system, the upper plenum, both front engine mounts, the air cleaner, the mass air flow sensor, etc.

Here is how I started:

And here is where I am now:

(This is looking in at the engine from the driver’s side.)

Since I have everything out, I might as well replace the gaskets on the fuel injectors:

I noticed a speck or two of dirt inside the rails. I’m trying to keep everything as clean as possible, but it’s difficult to do it perfectly.

Here’s why I have to remove three of the pushrods on each side:

In certain places the gasket overlaps the pushrod! The roller rockers will thankfully make the job relatively simple.

The single part on which I wasted the most time was this:

The bright thing in the center is where a heater core line plugs into the intake manifold near the thermostat housing. The Haynes manual says you are supposed to be able to just twist the black metal hose out of the shiny part, but I could not figure out how it is done. I alternately used a set of quick connect separators and a wrench to try to get it separated but nothing worked. I ended up getting out a 1 1/16” open end wrench and just unscrewed the shiny thing from the intake manifold. I now wish I had started out doing that. I hope this part does not leak when I am done!

This engine’s exterior is full of grease. I will spend a little time with Simple Green and paper towels before reassembly.

Obviously my Wal Mart brand 5W/30 oil and oil filters and infrequent oil change cycles haven’t caused sludge buildup. Try that on for size, you boneheads who use fancy, expensive botique oils!

Continue to part 2