These posts are starting to feel cyclical! LOL. With the long weekend, I decided to tackle the intake manifold gasket "re-re-do". To recap, the dual throttle bodies only have 5 vacuum ports in total. The largest being for the brake booster. I capped off the brake booster a week or so ago, and it had no affect on the high idle. This meant it was checked off the list as a possible culprit. The other vacuum ports are either capped (in which I pulled off the cap to inspect- All brand new and nice tight fit) or there is 1 small one used for the Vacuum gauge (also good fit and new fittings). As I covered 1 whole throttle body and the car stayed running with the throttle blades closed, this seems like something larger.
Long story short, I pulled the intake, and using brake/parts cleaner and a razor this time (instead of rubbing alcohol like last time), I cleaned the intake manifold. I then pressure washed it out with tap water, and then sprayed it down completely with parts cleaner again and dried it off with shop towels. Spotless, and squeaky clean.
As for the heads side, I plugged the oil drain back holes, intake ports and the distributor hole with shop towels to protect from debris. Then using the Parts/Brake cleaner and a razor, I cleaned the whole area over and over. I did not notice anything huge jump out at me, but when you pull the intake, some of the gasket goes with the intake and some stays on the heads.... So couldn't see any obvious sign of a leak.
Anyway, after All was clean, I used brake cleaner again and made triple sure it was free of any oil residue, gasket material or TA31 sealant. I even used the brake cleaner to clean the valley of the block to make sure nothing had fallen into the residual oil and was "hiding". After this, I cut out the cork triangles that seal up the space on the china walls where the heads overhang. Using a fair amount of TA31 sealant, I coated the cork triangles on the bottom, side that mates to the head and the side that touches the front timing cover. After pushing them into place (on all 4 corners), I covered the engine with a piece of plastic and let them dry overnight. This may seem excessive, but if you try sealing these up wet, they pop right out as soon as you start to tighten down the intake.
The next day, I moved on to the intake gaskets. Ensuring I had a good fit dry, I coated the mating surface (gasket to head) with a coating of TA31 around each port opening as well as around the gasket material where the bolts go. Like last time, I put it on slightly thicker around the water jacket areas. Then, I placed the gasket on the head and pressed and adjusted it around until all of the bolt holes and ports were perfectly aligned. About 15 minutes later (after I completed the other side), I went back and pressed around the gaskets again to make sure it was all making good contact and had not moved.
Then I let this sit for about 2 to 3 hours. By this time, they were sturdy in place and there was no change of them sliding when the intake was put on. so with more TA31 sealant, I put the mirror amount on the gasket to intake side as well as running a thick tall bead along the back rail and the front rail.... ensuring to go up the cork triangles on all sides (which were now sealed tightly in place and would not pop out!). Finally, I slowly lined up the intake manifold and lowered it into place. I did this as slowly as possible because I did not want to move it much before I started to run bolts in. Once I dropped it down, I inserted the Distributor (to ensure it was properly aligned before tightening it down. After about 3 taps to the drivers side (literally "Taps"), the distributor slipped right in!. Going around with a shop light, I could see that the bolt holes were also perfectly aligned and it did not appear that the intake gasket moved at all! All bolts were cleaned with brake cleaner and a brush to ensure they were spotless to go into the recently cleaned threaded holes in the head (Oh Yes, I went clean crazy cleaning all the threaded holes and vacuuming them out over and over!). Long story short (again).... all bolts went in no issues at all! Tightened them down sequentially in a pattern. I did not torque them down, but rather got them all evenly tight, and then did a quarter turn on the ratchet). Replaced the carb gaskets, installed the throttle bodies, re-aligned the distributor and all is back to normal. I will give it a few days before I add back the coolant.
Fingers crossed this worked..... but what I don't understand is how I could have that large a leak to begin with under the intake manifold.
