Question: I have a 1990 Ford F150 XLT Lariat with the 6-cylinder engine.  It has  98,500 miles and looks great but the engine is causing problems.  I just  bought it from my father-in-law and the Ford place he took it to told him  it needs a new engine.  It was missing badly and when you took off the  oil filler cap there was a white/cream colored goo all around it.  I took  it to a repair place and they gave it an electrical tune-up, flushed the  coolent system, did a coolent pressure test, flushed the oil system, and  did a cylinder leak-down test.  They also did a test to determine if water/  coolent was getting in oil or vise-versa.  All tests came back with no  problems!

I noticed two days after the oil system flushing that I was getting the  same white/cream colored goo in my oil filler cap!  Sporadically, the  engine oil pressure gauge drops to low and then comes back to mid-range!  The oil pressure drop really concerns me!  Do I need a new:

oil pressure gauge      oil pump      engine

Any advice would be greatly appreciated!!!

Answer: One of the causes of sludge (the technical term for the stuff you  describe) is a blown head gasket. One of the causes of low oil pressure is  worn bearings. As long as you like the truck, I think the relatively low  cost of that engine would warrant spending a couple extra dollars. That  way you start with a clean slate.  In any case, I would think that it’s highly unlikely that you’re going to  be able to get away with minor repairs on this one.    I have a similar problem with my ‘85 Buick Skyhawk (1.8L OHC). It’s got  major internal coolant leakage (when the mechanic cranked the engine with  the spark plug removed from the cylinder in question, water came flying out  in significant quantities). The coolant-in-oil condition has been present  for perhaps 6 weeks, but it’s only been driven for 1-2 hours in that time.

Would this indicate it’s also too late to save my engine? The mechanic  who looked at it suggested replacement, rather than trying to replace the  head gasket and whatever else might have failed, and is looking into  candidate engines now. I’m unsure as to which way to go, since it’s major  surgery in either case and hard to do a cost/benefit workup given my limited  knowledge.

I’d appreciate any (further) advice people might have; the responses  last time were very helpful.

Providing the cylinder leakdown test was accurate and there was no  leakage past the head gasket(s), the first thing you need to check is to  see if the cooling system is getting to proper operating temperature.  If  not, this could cause condensation buildup.  Also, Ford products are not  unknown to have PCV (positive crankcase ventilation) problems which could  affect sludge build-up.  If the oil cap was clean when the other services  were performed and then the “white goo” returned within two days, I would  suspect an intake manifold leak into the crankcase.  If the oil itself  does not have coolant in it yet, (which would show up as droplets on the  dipstick or also white sludgy stuff), then it may not be too late to save  the engine.  If there has been any appreciable amount of water/coolant in  the oil for any length of time, then it can definitely harm the bearings.  This may be why the dealer condemned the engine.  I suggest you have your  local shop do a pressure test of the cooling system and see if there is  any loss in pressure.  If there is a drop but no sign of external leakage,  it probably is the intake manifold gasket.

Related posts:

  1. HELP!!!!!Ford F150 exhaust?
  2. Engine Oil Pressure too HIGH … HELP!!!
  3. 1997 ford f150 engine noise?
  4. Choice of gauges
  5. What gives: Too cool in winter and too warm in summer?
  6. Choice of gauges
  7. Engine lopes when cold