1New recruit, hello, and help i have no clue what I'm doing anymore


New Member
Jul 3, 2019
Jackson, MS
I bought a 2000 Mustang GT 4.6 liter convertible 5 speed a little over a year ago for just under $1,500 seemed like a good deal at the time. For the price anyway. Over the next few months have replaced brake parts EGR spark plugs coil packs IAC valve a multitude of tires and three alternators- it was a faulty 3 prong wiring harness making the alternators go bad -

Jump forward to today.....
My car is sitting with the hood up in front of a friend's house in North Jackson Mississippi where it has been a literal carcass to the buzzards and birds of prey that are Jackson's vagabond citizen population.
Although I have been lucky enough that none of these dumb A's have taken any engine components from it. A few weeks ago I allowed a friend to borrow my car and he drove it against my wishes as I asked him to put gas in it first how to check all fluids what she did not do. My car has a somewhat tricky electrical system and every car has their special quirks I'm sure I currently have I believe I ccrm problem where my fan relay is stuck in constant open unless I pull the fuse it is always running even with the key out of the ignition. Therefore my buddy drove the car about 5 miles on the highway more than likely engine Wide Open high RPM with the fan not on at all. I'm sure he didn't top off the coolant reservoir either like I asked. Anyway he calls me a few hours later and I get to the car after he puts gas and water in the engine and the car will not start. I turn the key and the engine turns over but it seems a little bit more sluggish than usual. Perhaps it is just me. I unscrew the engine oil cap and underneath it is a frothy milky substance water has mixed with the oil the worst of my fears has been concluded. I have already begun tearing down the top end of the car I currently have the majority of the top end apart. Intake manifold throttle body air intake system or disconnected and removed as well as the alternator and the water pump I have removed all necessary bolts in the timing chain covers including the Forefront that go underneath that connect to the oil pan. Upon inspection of my intakemanifold I noticed that the ports on the underside of the plastic manifold itself seemed to be cracked and have faulty looking passageways it seems. I've heard a lot of negative feedback on these Ford plastic manifolds. What I'm trying to ask and say here is could a correct plastic intake manifold be the cause for the water mixing in with my oil? Because if so it could save me time from having to fully remove these heads and have the blocks resurfaced and what not. Because this has been a long drawn-out situation and I hate getting repetitively greasy and having to get clean every day after work. Any feedback would be very helpful questions of any kind I'd be willing to answer immediately I will post pictures here in a second to give you a little visual thanks guys...love , Joseph
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No, an Intake issue will not generally cause cross contamination with Coolant entering engine Oil.
1) Drain that oil out of the motor if you have Coolant in it, it damages engine bearings faster than Boris Yeltzin swills Vodka.
2) The Oil filter housing is one area that deals with coolant and oil, if the gasket is bad, or the housing is cracked, that may be your issue.
3) The Oil cooler for engine oil is another spot this cross contamination may derive from..
The 96’-early 2001 Polymer Intakes are notorious for cracking all over, the most prominent area(s) are the front coolant crossover that was already a factory repair in the 4.6l Mustang GT’s in April of 2001. This is identified by the plastic intake manifold having an aluminum crossover in the front.
If you have an aluminum crossover-good. If not, replace it with either a Ford OE Intake or aftermarket Intake to avoid future problems.
Some 2001’s may still have the issue of coolant leaks at the front of the Intake and where the heater hose connects.
An intake coolant leak, however, will not generally end up into the engine oil. it’ll get pulled into a Combustion chamber and be cooked off in the process, you’ll note a sweet smell from the exhaust, followed by a misfire & CEL shortly afterwards.
The best idea(s) to locate the leak:
1) Run a compression test on each Cylinder.
2) Run a leak down test on each Cylinder.
3) Perform a coolant system pressure test, which most part stores rent the proper tools for. This will identify your coolant leak path.
Did you note bubbles in your Coolant while the engine was running, or did it overheat?
As it’s usually engine compression that initiates a head gasket failure, that’s generally the symptom what occurs with a blown head gasket, but it may present differently.
-Somewhat rare for a 4.6l V-8 to have a blown head gasket, unless another has already had it apart, but there’s always the chance it may occur..
+1 on most of the above. However, I do agree to look at the oil filter adapter as a possible spot for oil/coolant mixing. I don't agree that it's not possible for a bad intake manifold to be the leak source. Regardless it's fairly obvious that a new intake manifold is needed.

If this were my car I would most certainly do the compression test. After all it's silly to replace an intake manifold IF there is also a head gasket or cylinder sealing issue going on. Best to have some idea about what you are in for before spending real $$'s.

If it does turn out to be something more serious all hope is not lost. Research Windsor to Romeo swap. I did this on my 2000 GT. That was 7 years and 100K miles ago. Very cost effective way to get a car with a blown motor back on the road.
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Hi, Apologies if my comment came across as it’s “not possible” for the Intake to cross contaminate coolant with engine oil, it wasn’t intended to be interpreted that way, it’s just “not generally” as frequent as the others listed, based on personal experience.The Car’s certainly worth the effort, good call WMBurns suggesting a Windsor to Romeo swap, if it comes to that. Get yourself a Chiltons or Haynes Shop Manual, if you didn’t buy one, already.
Hopefully not, but IF the worst, other options: P.I. parts are reasonable, even brand new(Heads, Intakes, Cams). You can also find an ex Police P71 Crown Vic with a 4.6 P.I. motor, running for 1,000$, Being an ex Police vehicle They’re beaten, Idled extensively, but aggressively maintained. How do I know this? A good friend runs a Shop that maintains them. Most all major parts are identical, plenum needs to be flipped as it’s on the Drivers side, Flywheel, etc. between the 2 Cars, it’ll work.
Do a compression test on it if desired, drive it first. Tear off a Valve cover, Whatever.
The 4.6’s are resilient workhorses, 2011’ I’d bought a Dark Grey 06’ P71 Crown Victoria 4.6L P.I. Likely Idled extensively and driven very hard by State Police with 170K on the Odo, for 800$. First as a Winter beater, then a D.D, With regular maintenance it’s just spun 260K & running as strong as when I’d bought it., biggest issue- a Transmission Cable. And I beat the living crap out of it.
Getting friendly with a local parts store that rents out specialty Tools may save you some $$ as well. Just Don’t give up!
Good luck!!