Lower Intake Manifold Gasket, 1996 3.8L

[wiswind]

I finally got around to working on my leaking lower intake manifold gasket.
Once I got things apart, it was obvious that I had been leaking coolant into the cylinder #1 air passages for some time. Also, the crankcase right below, is subject for coolant to drip into the oil.

My brand new "clicker" torque wrench did not "click" and my cold (windy, 40 degree day, untrained (emphasis on untrained) ) hands did not catch on, so I broke a bolt.....and decided to continue....and then take it to a good mechanic to be certain to get it done right.
I am NOT a mechanic.....and I run into "challenges" as much as the next guy.
I would have gone to the mechanic anyhow, as I developed a serious misfire at cylinder #4.....right next to a water passage.....which I was told was caused by a fouled fuel injector.
(can of Berryman's Chemtool B-12 to a tank of gasoline).

HOWEVER, I did take pictures, and posted them, and this post, to help others.
The link to the pictures is in my "signature" at the end of this post.


My mechanic told me that I was correct to go to FORD to purchase the lower intake manifold gaskets, as they have made updates (improvements) to them that are not yet available in the aftermarket gaskets.

The FORD dealership told me that 3mm gaskets should be used if the heads have not been serviced, as in machined.
If the heads have been serviced, the machining will make the spacing slightly wider, so you will then need the 4mm size gasket.

ANYTIME the lower intake manifold is removed, you MUST replace the lower intake manifold gaskets.

You will also need to purchase the "end seals" which seal the ends of the lower intake manifold gasket.
The newer end seals are slightly thicker. For this reason, they recommend that you install bolts #3 and 4 first....and snug them down slightly, then install the other bolts.
There are 14 bolts, 6 long, and 8 short.

At the same time, I also replaced the "cross over pipe" which has a "U" shaped hose at one end. This takes the coolant from by the water pump, over to the driver's side of the car...through the lower intake manifold...for the heater "IN" hose to connect to. The "U" shaped hose is part of the cross over pipe assembly.
I have this shown in my pictures as well.

The heater "IN" hose on the driver's side is 3/4".
It has a quick connect which is also 3/4".
I bought the special tool to release the quick connect at autozone for $12.
It was a long bar.....that I needed to cut in half, in order to be able to get down into position to get onto the plastic clip.
I would STILL recommend buying a replacement clip, spacer, and 2 "O" ring gaskets to replace the ones that are in there. FORD sells them in a kit.
This is because, as in my case, after all these years, the clip may fall apart...(brittle)...and most likely WILL if you do not use the tool to release it.
Good instructions on working with the heater hose quick connect can be found under the Aerostar repair guide at the autozone repair information site.
http://www.autozone.com/servlet/UiBr...3d8014b8e8.jsp

You will also need to buy the RTV sealer, that meets FORD specification #ESB-M4G92-A and ESE-M4G195-A. Use of the incorrect RTV could cause failure of the oxygen sensors (sensor safe) as well as not sealing correctly.
You place the lower manifold gasket, then put a small (3mm / 0.125") bead of the RTV at each lower corner of the gasket....where the head meets the block. Don't over-do it with the goo.

You will need to seal the threads of ALL lower intake manifold bolts with pipe sealant that meets FORD specification WSK-M2G350-A2.

This is also a good time to change the coolant, as you have drained much of it to do the repair.

When you remove the lower intake manifold, you WILL get a significant amount of coolant into the oil. For this reason, you MUST replace the oil and oil filter.

[LeSabre97mint]

Wiswind

Nice post! Sorry you had problems! Glad you were able to get it done and stop that coolant leak!

Regards

Dan in MN

[busboy4]

Hey Wiswind,

As always thanks for a fine post. What prompted the "tear down"? I have a high mileage 3.8L '96 and am curious. As it stands I have an occasional misfire on 3 and 5 (for now seafoam seems to have done it). However no steady loss of coolant.

Another quick question. Looking at your photos: the view below the lower manifold - what is the machined "half tubular" assembly that runs end to end above the cam? My base knowledge fails me here.

Thanks

[wiswind]

I did the tear down because of a slight loss of coolant.
The 2 locations on the 1996 subject to leakage is the lower intake manifold gaskets, and the "front cover" aka timing cover gasket.
I had my oil analysed by Blackstone Labs, and there was a very slight amount of coolant in the oil. I also knew that I had leaking lower intake manifold gaskets as I had found a green stain on one of the upstream oxygen sensors.
FORD has improved the gaskets, so the new gaskets will be more reliable.

The "Tubular" shaft that is above the cam in my "under the lower intake" picture is a ballance shaft. A 60 degree engine, such as the 3.8L can have a vibration, and the ballance shaft is to cancel that vibration out.

For your slight miss, I would put a can of Berryman's Chemtool B-12 into a tank of gasoline. This is a solvent type of cleaner.

I have just over 163K miles on my windstar.

[busboy4]

Thanks Wiswind

My van is at 135K. I have had the coolant loss around the timing cover, but it (to my knowledge) has been external. I have been able to stem the leak by going through the right wheelwell and tightening the timing cover fasteners.

I'll try the chemtool next time around. I have used seafoam in the intake and in the gas as directed. Seems to have cleared up the issue for now.

[wiswind]

I have Bar's Stop Leak in the coolant, and plan to continue that for the timing cover. That is much more major on the repair scale than the lower intake manifold gasket. FORD has also improved the gaskets for the timing cover from what is now in there.

The timing cover leak can also leak into the oil.
If you wonder if it is getting into the oil, you can go to www.blackstone-labs.com and have them send you a free sample kit. You take a oil sample when you change your oil, and send it in to them. It costs $20 for a basic analysis, plus less than $3 shipping. Well worth the cost. They will tell you if there is any coolant getting into the oil. It can be causing serious damage to your bearings LONG before you can eyeball detect it in your oil.

The '96 3.8L is NOT as prone to head gasket failure as the '95 was. They made improvements for the '96 model year.
Many vehicles are prone to develop leaks at the lower intake manifold gaskets, so I do not feel bad about having it on my windstar.
I expect to have repairs at going onto 10 years and the miles.
I only have 1 vehicle, so letting it sit while I take time to work on it is costly as I would need a rental car.
I am happy that I have found a shop that I can trust to repair it right, and feel quite confident with the job that they did.

UPDATE!!!!
I found that the FORD dealer sold me the wrong sealant for the corners of the gasket set.
I provided them with the FORD specification numbers, and they still gave me SILICONE RTV sealant.
You MUST not use silicone, as it will damage the oxygen sensors.
I have removed the pictures that showed that nasty tube of sealant.
I still have the correct FORD specification numbers, as found in the TSB, posted.