Oil in Coolant/Lower Intake Gasket

[tomj76]

I've been using oil and coolant for a while now, and had not found the cause until recently. I believe have a leaking lower intake gasket, which I will replace tonight. I can only hope that nothing is cracked and that the head or head gasket is not involved.

The oil has not shown any signs of emulsified oil/water and tests fine, but the cooling system is another story. At this point there is a fairly large amount of oil sludge in the radiator. I'm not running hot, as I can monitor the temperature readout using my scanner while driving. The only time I notice any issue with temperature is when running on long hills, or when sitting in traffic, which will lead to a 5-10 deg F rise in the temperature readout.

I'd like to flush the coiling system out with something that will remove the oil sludge. I've read about using soap (i.e. automatic dishwasher detergent) and I've considered "Lestoil" which is household degreaser that I've used to clean parts at times. Does anyone have any additonal suggestions?

Also, I had to abort my first try to replace the intake gaskets last Saturday night because one of the bolts would not turn. After I rounded off the head with my 7/16" six point socket (why such a small head!!), and knowing that I did not have a replacement, I decided to wait until I had a few replacment bolts available to complete the job. It's the first "low" short bolt next to the #1 cylinder, very hard to access with a cutoff wheel or anything like that. I also can't get in there with a hammer and punch to turn the bolt. I'm planning to use a drill or Fordham tool to remove the head, then remove the manifold with the shaft of the bolt still in place. Any better suggestions?

[12Ounce]

Originally Posted by tomj76

.............oil has not shown any signs of emulsified oil/water and tests fine....

I'd like to flush the coiling system out with something that will remove the oil sludge. .........

It's the first "low" short bolt next to the #1 cylinder, very hard to access with a cutoff wheel or anything like that. I also can't get in there with a hammer and punch to turn the bolt. .......... Any better suggestions?

Have you had the oil tested by some lab such as Blackstone Lab? A small amount of coolant in the crankcase oil will do tremendous damage/wear. You will never be able to detect such a small amount by observation or home-tests (unless you are a sho-nuff chemist). If you have coolant in the oil to the extent you can see it ... you have a wiped out engine.

A bit of oil in the coolant, on the other hand, is not a problem ... just a unsightly mess. Forget the coolant reservoir until you have the crankcase in order.

There is a good chance that the crossover leak is in the lower intake gasket ... it can be tricky to get just right. (Another leak candidate is the front cover gasket.) I always use a torque wrench and closely follow Ford procedure. Even so, I have had one failure in four or five replacements ... all done "by the book".

The bolts holding the lower intake to the block can be troublesome. I have had trouble with them ... it got a bit better after two of the end-bolts were replaced with home-made studs ... makes the alignment easier. I'm not sure exactly which bolts you are having a problem with .... and its been quite some while since I have done this task.

I leave the reservoir pressure cap a half-turn loose to help keep high pressure coolant forcing its way into the crankcase. I can do this since we never travel in high elevations.

[tomj76]

>I'm not sure exactly which bolts you are having a problem with .... and its been quite some while since I have done this task.

The lower intake has two types of bolts holding it down, shorts one that are 6 mm x 1 mm x 32.5 mm, and longer ones, that are 6 mm x 1 mm x ~60 mm. The long ones are located along the "interior" of the manifold, while the shorter ones are around the perimeter. I believe there are three short ones along each of the top two edges of the manifold. There are also four short ones along the edge of the manifold, near the bottom of the head at the front and back of the engine. The one that's stuck is one of those four, right next to the #1 cylinder, behind the power steering pump.

Those bolts are held in by a thread locking compound, probably because the torque is fairly light ~10 ft-lbs.

Prior to my first attempt I could see coolant building up along the top edge of the lower manifold gasket, between cylinder's four & five, so I know that I have a leak there at a minimum. I also noted oil and coolant on the manifold bolts that I removed from that area, and none on bolts from the other side of the manifold. However, what's there will be revealed tonight when I get that last bolt out.

[wiswind]

I have pictures that detail the process posted in the pictures that the link in my signature takes you to.
I would use a BEAM style torque wrench (not a "clicker") and note INCH POUNDS, not ft pounds on some of those bolts.

Do NOT use any extra sealer on the lower intake manifold gaskets.
They do recommend the sensor safe sealant (included in some gasket kits) at each end of the "end seal" right at the corner where the end seal and lower intake manifold gasket meet.....just a small dab.

This is a good time to replace the thermostat (I would use Genuine Motorcraft brand) as you are right there.
I was able to keep the fuel rail attached......just moved it over and hung it out of the way......I did the same with the upper intake manifold/throttle body.

Take extra care to avoid dropping any dirt/grit/cleaning fluids down into the intake ports.
Anything left down there is sitting there ready to be drawn into the cylinders when you start up the motor.

A oil/filter change is MANDITORY before trying to start the motor.

One thing that I like to do when having the fuel rail off.......after putting it back into place......but before I install the upper intake manifold......I turn the ignition key to the RUN position but DO NOT crank the motor.
This will get the fuel pump to pump the fuel system up to pressure.
Then I look over the fuel rail to check for any leaks......as it is all exposed and easy to inspect at this point.
Then I turn the key to OFF and remove it......and proceed to finish putting everything back together.

[12Ounce]

Yes, you are helping me remember more detail ... the bit about the two different length bolts. My "problem bolt" was a short one toward the back of the engine. It came out ... but brought metal with it. I think it was cross-threaded a bit by Ford. Since, at that time, the heads were also coming off, I considered installing a thread insert ... but instead merely retapped the threads.

Good luck with yours ... hope you don't have to install insert ... but if you do, ain't that bad ... just make sure to cover/protect the inside of engine.

[tomj76]

I completed the job. Getting the bolt out wasn't quite as difficult as I expected. I used the "dremmel tool" to cut a slot in the head so that my punch had something solid behind it at the right angle, then used a hammer on the punch to turn the bolt. After it was started it came out easily.

There was a lot of hard carbon build-up in the intake passages ~30 mils thick, so I tried to clean that while I had it apart. There wasn't much evidence of oil sludge in the water passages, so I think my sludge is only in the radiator. I didn't have time to flush the radiator while I had it drained, so that's a job for another day.

The installation was more interesting, as I had issues with continuous misfiring on #6. I checked & cleaned the plugs of carbon and oil, but that didn't cure it so I swapped the injector to see if the problem moved with the injector. I had swapped #4 with #6 during installation anyway. It started running without the misfire at that point, but now I'm getting P0401 (low EGR flow) that I've traced clogged DPFE ports on the EGR pipe. They are filled with dry carbon, no exhaust flowing with the DPFE hoses removed. Being curved, I can't use a drill bit to open them up around the corner.

I'm also not completely sure that I've got a good seal on the intake, as the scan tool reports LTFT at idle that is +8% on bank 1, and +12% on bank 2. Bank 2 is where I had the coolant leak before starting. That said, there is a lot of carbon in the exhaust while I let it idle (implying a rich mixture, in conflict with the computer). Once I get the DPFE ports working again, I'm thinking that I may have excessive build-up on the O2 sensors.