Hey guys,
I bought a 98 4runnner with a 3.4 that had a blown head gasket as a project car. It has 240,000 miles but seemed pretty well taken care of by the previous owner of 5 years. He told me a mechanic did a leak down test and it showed it had a blown head gasket on the driver's side. It still ran well but had milky oil and white smoke coming from the exhaust. I replaced the driver side gasket and had the cylinder head machined. Since I got it back together, it is still blowing white smoke from the exhaust and has milky oil. The only difference I noticed is that the oil seems a lot milkier than before. Keep in mind, I only put about 10 miles on it of driving around my neighborhood. I am comparing this to the 10 miles I drove to get home from the guy's house I bought it from. Both of these 10-mile intervals were done with fresh oil as well. I did a compression test today and it showed about 185 PSI on all cylinders. I am looking to see what anyone thinks about this. Is there something I could have missed while putting it back together? Could the intake manifold gasket do this? Thanks to anyone who takes the time to read this and respond! 4

 

Don't run it anywhere with the milkshake showing. Either in the coolant, the oil, or both. It's showing a severe change in oil viscosity, coolant heat transfer capability, and so forth. It's a good way to spin a bearing. Something like that.

Could you have gotten the head gaskets on the wrong sides? Could they be upside down? Are the head bolts torqued properly? Like in the right sequence. Did you torque them a little at a time? Could you need new head bolts? Could you have a leak in the radiator? SOMEhow, oil and coolant are mixing. It has to be stopped before you drive it anywhere.

Does a spark plug on one side look different from the others? They can tell the tale fairly well.

Just the few thoughts I got. I hope something is helpful.
Pat☺