While replacing the head gasket on my 2003 MCS (long story that led me to the head gasket, but includes coolant squirting out of #3 spark plug tube) I noticed an oily residue inside the horns of the intercooler. I also found the same residue on the backside of the throttle body. It was worse on the throttle body. Was this possible from the head gasket failure, normal Oily residue inside intake horn.
Oily residue on underside of throttle body.
, or signs of more problems?

 

yep it's also known as the r53 catch can

 

How many miles on the car as IMO that is allot of oil. The R53 has no where near the amount of oil going back into the fuel/air as the Gen2 Turbos. Have you checked to make sure the PCV is not shot?

 

The ole girl has 188k miles. I'm sure it does need a PCV. There was some nasty milky junk on it when I took it out. That issue should be solved with the new head gasket.

 

My last parts came in today and got it all back together. The excitement didn't last long when the missfire and moisture in spark plug tube #3 came back. Can the spark plug tube come out? I didn't see any way how when I had the head off without a press or something. . It doesn't feel or look any different than the other three. There isn't any indicator the tube has any problems aside from the presence of burnt oil and/ or coolant in there . Due to my lack of time, patience, and money I didn't have a machine shop check the head. 😤

 

I do not know what the coolant plumbing route is within the head but in order for coolant to be in the tube would think the head is cracked on the top side of the head that is allowing the water into the tube. Perhaps somebody can chime in on whether the tube is threaded in or welded on.

 

I will find out more on Monday. I'm removing the head again, this time I'm taking it to a machine shop. They will hopefully be able to help me out.
My head bolts have about a total of three days being torqued in the head and then ten minutes run time today. Think I need to buy a new set again?

 

Some extra info on my situation, the cylinder in question has been tapped and has a heli coil in it. That had already been done when I bought the car. Wondering like you, Walnuts, if there is a crack in that area .This may be the source if my grief.

 

The heli coil may be the issue. Its a gamble but I would try some high temp thread sealant on both the sparkplug threads and the sparkplug washer. I know there are sealants for steam fittings that are good up 500 degrees F.

 

When I had the head off I put some permanent thread locker that said it was good up to 300 deg. I dont know how well it will hold up, but it held so far. The helicoil sleeve had started coming out with the plug lately so I tried the thread locker from Harbor Freight.

 

Getting impatient to find out what the machine shop says tomorrow. Further inspection shows more reason to believe the #3 tube itself may be my problem.
Highly scientific

 

That sure looks like it is threaded and backed out. Need a Nick at Detroit Tuned or Way at Way Motors to chime in as they are vendors here with their own repair shops and have a whole lot more experience than most of us have here.

 

Verdict is in, my head is trash. Found several cracks around the helicoil. Some even reach the valve seat. Time to shop. Any suggestions on buying a good used head?
Not sure the title of this thread is appropriate anymore, its more about cylinder heads than the oily intercooler.