Lower intake manifold gaskets
busboy4
11-09-2006, 09:12 PM
Hi
1996 3.8L with 143K. After noting a small but steady coolant loss, I suspected the lower intake gaskets. I sent my oil off to Blackstone labs and found that I indeed had a small amount of coolant (.24%, target 0) in the oil. I had time, and elected to do the repair. Many thanks to Wiswind for a fine description of the process, for his website with photos, and for kindly answering a few private emails to help me prep for the job.
: http://www.automotiveforums.com/vbulletin/showthread.php?t=549207&highlight=head+gasket
http://community.webshots.com/album/201931518cScpNK
I purchased a gasket set from my local Ford dealer (F68Z-9433-C) that included the lower gaskets (2), end seals (2), upper gaskets (6), IAC gasket (1) and throttle body gasket (1) for $52. I could have ordered from y2kford.com for $40. I did order new radiator hoses and a thermostat (Motorcraft) from y2kford.com and I recommend them. Additionally I purchased a new connector and o-ring assembly for my heater outlet hose, as shown on Wiswind’s photo page (E69Z-18D434-A) I also researched which compounds to use for the gasket sealant and thread sealant as recommended in my Ford OEM manual. For the gasket sealer at the ends of the end seals I used Permatex Ultra Black silicone RTV. It referenced the Ford OEM specification. For the thread sealer for the lower manifold bolts I used Ford TA-24 thread sealer as shown in Wiswind’s pictures. I found that Permatex High Temp thread sealant also meets the spec. as well as Loctite PST-592.
Overall the project went very smoothly. I chose to remove the cowl to begin. I have had it off several times and it really makes almost any job easier. I had one upper and one lower bolt that needed an EZ-out socket to pull. Some of the lower bolts are a bit hidden near the IMRC valves. As did Wiswind, I did not totally remove the IMRC’s, but simply loosened them to have access to the bolts located nearby. I also chose to not remove the heater by-pass tube in the lower manifold, choosing instead to lift it out with the tube, minus the U shaped hose, intact. The dis-assembly was overall easy requiring only an 8mm and 9mm socket for 99% of the job. I used masking tape extensively to label the miriad of vacuum lines and electrical connections that had to be opened. .I did not disconnect the fuel lines to the injector rail, but simply used a bungee cord to hold the rail, injectors and all up out of the way once the injectors were free of the manifold. Once apart, it was apparent that my lower manifold gaskets were utterly spent. I did not see obvious indication of coolant ingestion, but clearly coolant, oil and air were all likely going places they should not have been.
Really the bulk of my time was spent cleaning the ports of the intake system including the upper manifold, lower manifold and those in the head. There were extensive carbon and tar like deposits throughout. I went through about 8 large cans of carb cleaner.
Re-assembly was fairly easy as well. The lower manifold went into place easily after the gaskets and RTV were in place. I used the thread sealer on each bolt and tightened them initially to 92 In-Lb, and then went back and re-torqued to 96 (Ford spec. was 71-106). It is really surprising how little torque that is: during dis-assembly many of the bolts seemed surprisingly loose. I used the same torque method and values for the upper intake as well, and although not mandated in the manual I used anti-seize compound on the upper bolts as the one was somewhat stuck on dis-assembly.
My engine idles smoother and quieter than before, and I am anxious to see if it will run “quiet” on 87 octane now. I had been running 89 to avoid occasional knocking.
Unfortunately, while running the engine after the repair, I developed a very large coolant leak, which I was able to trace to the water pump. Next post.
1996 3.8L with 143K. After noting a small but steady coolant loss, I suspected the lower intake gaskets. I sent my oil off to Blackstone labs and found that I indeed had a small amount of coolant (.24%, target 0) in the oil. I had time, and elected to do the repair. Many thanks to Wiswind for a fine description of the process, for his website with photos, and for kindly answering a few private emails to help me prep for the job.
: http://www.automotiveforums.com/vbulletin/showthread.php?t=549207&highlight=head+gasket
http://community.webshots.com/album/201931518cScpNK
I purchased a gasket set from my local Ford dealer (F68Z-9433-C) that included the lower gaskets (2), end seals (2), upper gaskets (6), IAC gasket (1) and throttle body gasket (1) for $52. I could have ordered from y2kford.com for $40. I did order new radiator hoses and a thermostat (Motorcraft) from y2kford.com and I recommend them. Additionally I purchased a new connector and o-ring assembly for my heater outlet hose, as shown on Wiswind’s photo page (E69Z-18D434-A) I also researched which compounds to use for the gasket sealant and thread sealant as recommended in my Ford OEM manual. For the gasket sealer at the ends of the end seals I used Permatex Ultra Black silicone RTV. It referenced the Ford OEM specification. For the thread sealer for the lower manifold bolts I used Ford TA-24 thread sealer as shown in Wiswind’s pictures. I found that Permatex High Temp thread sealant also meets the spec. as well as Loctite PST-592.
Overall the project went very smoothly. I chose to remove the cowl to begin. I have had it off several times and it really makes almost any job easier. I had one upper and one lower bolt that needed an EZ-out socket to pull. Some of the lower bolts are a bit hidden near the IMRC valves. As did Wiswind, I did not totally remove the IMRC’s, but simply loosened them to have access to the bolts located nearby. I also chose to not remove the heater by-pass tube in the lower manifold, choosing instead to lift it out with the tube, minus the U shaped hose, intact. The dis-assembly was overall easy requiring only an 8mm and 9mm socket for 99% of the job. I used masking tape extensively to label the miriad of vacuum lines and electrical connections that had to be opened. .I did not disconnect the fuel lines to the injector rail, but simply used a bungee cord to hold the rail, injectors and all up out of the way once the injectors were free of the manifold. Once apart, it was apparent that my lower manifold gaskets were utterly spent. I did not see obvious indication of coolant ingestion, but clearly coolant, oil and air were all likely going places they should not have been.
Really the bulk of my time was spent cleaning the ports of the intake system including the upper manifold, lower manifold and those in the head. There were extensive carbon and tar like deposits throughout. I went through about 8 large cans of carb cleaner.
Re-assembly was fairly easy as well. The lower manifold went into place easily after the gaskets and RTV were in place. I used the thread sealer on each bolt and tightened them initially to 92 In-Lb, and then went back and re-torqued to 96 (Ford spec. was 71-106). It is really surprising how little torque that is: during dis-assembly many of the bolts seemed surprisingly loose. I used the same torque method and values for the upper intake as well, and although not mandated in the manual I used anti-seize compound on the upper bolts as the one was somewhat stuck on dis-assembly.
My engine idles smoother and quieter than before, and I am anxious to see if it will run “quiet” on 87 octane now. I had been running 89 to avoid occasional knocking.
Unfortunately, while running the engine after the repair, I developed a very large coolant leak, which I was able to trace to the water pump. Next post.
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