I have an 86 bronco with a re-manufactured 351 from Autozone (now i know was a mistake). I'm getting oil in the coolant that looks like cappuccino. I'm not getting coolant in the oil. Friends have told me that its the intake manifold gasket. When I changed it there was no evidence of any gasket problems and I still have the same thing going on. Other people said it could be the timing chain cover gasket. I don't want to change it if it's not going to fix the problem. The Truck seems to run fine(except for poor gas mileage). With hotter weather coming on I don't think oil in the coolant is a good thing. Any ideas???????

 

Automatic transmission? If so, transmission fluid cooler in the radiator.

 

i also changed the modulator vavle in the transmission. And bypassed the radiator with a external transmission fluid cooler and nothing changed. Also the transmission fluid level is ok.

 

Are you sure it's oil? Your cappuccino description sounds typical of water in the oil, whereas
oil in the water will float and make colored streaks.

 

If it's truly oil in the water, it has to be coming from a place where both oil
& water meet (barring a crack in the block or sumthin').

Oil pressure is typically 30-60 or so lbs, coolant is around 14.

Only thing thatcomes to mind is the timing chain cover on the front of the
engine, do both fluids meet there on this engine?

 

Take it somewhere and get a leakdown test done on the coolant system. If there is a leak where oil is getting into the coolant, then the coolant system will not hold pressure during the test.

I am trying to think where oil could get into the coolant. Considering the coolant system runs around 13lbs of pressure(you do have a good radiator cap?) any type of leak where the oil is just splashing around inside the engine is not going to overcome 13 lbs of pressure and get into the coolant.

The oil does run up around 10-40 psi in the oil passages, and I am trying to think where this pressurized oil could get into the coolant. Nothing comes to mind right at the moment, and if there was a problem, it would be a crack in a casting somewhere.

You could also get the coolant checked for combustion gases. They have a test for that, and that is a more likely scenario, since combustion has much more pressure than 13 lbs.

 

There could be a hairline crack in the block somewhere.