95 windstar engine knock

I have a 1995 Windstar, 120,00, 3.8l. When I cold start the engine in the morning, there is a loud knocking sound. I think it's coming from the middle of the engine, not sure though. It has to be internal because if I rev up the rpm, the knocking sound goes faster. But after 5minutes of driving, as soon as the engine warms up, the knocking sound disappear and runs smoothly. I can start the engine without the knocking sound when the engine is warm or hot, only when the engine is cold. Anyone had this problem with a 95 windstar? Thanks

I have the same problem with my 96, still have not pulled the oil pan to have a look. Waiting for warmer weather, the link below is my post about the problem.

http://www.automotiveforums.com/vbulletin/showthread.php?t=941184

kevink1955, thanks for your reply. I plan to change my oil and filter this weekend. How did you checked the oil pressure, what instrument did you use and where to hook it up to. My 95windstar don't have an oil pressure indicator on my dashboard. I also ordered and received an oil sample kit from Blackstone Lab and have my oil analyze. Before the knocking problem, my 95 windstar had a cooling system problem. There is no heat, only cold air coming from the vents, sometimes it overheat, sometimes not, and keep on adding coolant.

The oil pressure sensor is located under the bracket that holds the alternator and power steering pump....down by the A/C compressor.

It is a switch.......that lights the light on your dashboard when the oil pressure is too low.
This is the spot that a sending unit for a oil pressure gauge would be installed.

Here is a link to a picture that I took, with the Alternator/power steering bracket removed, that shows the location of the oil pressure sensor switch.

http://community.webshots.com/photo/fullsize/1349972354011220610YwOpbP

Now, if you have been needing to add coolant.....and it is not leaking externally.....it could be a bad situation for the internal motor parts....so I would recommend digging into the situation ASAP......locate the source of the leak (the 2 most common internal leaks are front cover, aka timing cover, gasket and the lower intake manifold gaskets).
Blackstone has given me a fast turn around on my oil samples......make sure to include your phone number and email address, and you will get your results within a couple of days....instead of a week or more.
The critical thing you need to know is if there is coolant in the motor oil.

I change the oil and filter yesterday. And when I start the engine, I didn't hear any loud knocking sound. :wink::confused: I mailed the oil sample to Blackstone today and should received a reply in a few days. I'm still confused about the knocking sound. How come it's not there after I change the oil and filter?

I had the same on my 3.0l 96. Finaly there was a crankshaft defect due to low oil presure for a longer time. A total engine rebuilt was done and now it works fine...

Maybe you had a bum filter......or...if there is coolant leaking into the oil....you now have fresh oil without coolant.....for a short while.

The results from Blackstone are CRITICAL at this point.

I finally received the oil analysis from Blackstone Lab. The report confirmed that coolant is leaking inside the engine. The report said that 3.75% coolant and 2% of insolubles are in the oil sample. Wiswind, you're right when you said that since I change my oil and filter. the knocking sound stop because fresh oil was inside and no coolant mixed into it yet. It's running real good right now, no knocking sound, coolant level is okay. I add a bottle of Bar's no leak after replacing coolant from the radiator. Now, my question is, where to start to find the leak. Is there any hope for this engine? Thanks for your help

OK....the 2 most common leak points to get coolant into the oil are the lower intake manifold gaskets (I have pictures of what is involved with this job posted) and the front cover (aka timing cover) gasket.
With a 3rd that I am tacking onto the end.

The front cover is what the water pump and oil pump are mounted on.
Changing that gasket is well out of my league.......major job.
I was successful in sealing that up with Bar's Stop Leak....and it has held for many years......and well over 100K miles.
I caught mine when it was just a very slight seapage......out of the engine.
My dealership recommended just ignoring it......so slight and so expensive to repair......so I went the Stop Leak route.

The stop leak did not stop the leaking lower intake manifold gaskets.....
I did gain some temporary relief....but still had leakage.
Now.....lower intake manifold gaskets can leak into the intake....and the coolant is drawn on into the cylinder(s).....which can cause a mis-diagnosis of head gaskets.
The head gaskets on the post 1995 3.8L windstar are not a common failure.
For this reason......I would look at the 2 items I mention.

The 3rd....less likely...but possible...and I CERTAINLY would replace it if I were going to do the lower intake manifold gaskets....since you are right there anyhow......the "cross over" tube (aka bypass tube) that you see in the pictures for in my lower intake manifold gasket series.
This pipe has been known to spring a leak.....
This pipe passes through the lower intake manifold.....seats into the driver's side of it.
On the passenger side.....which is where it passes through INTO the lower intake manifold.....it comes out of the lower intake manifold and makes a 90 degree turn....and heads toward the passenger compartment....at which point ....There is a small "U" shaped hose on the end of it...that points back toward the front of the car....and connects to a tube from the water pump.

My leak into the oil was much less than yours......and my Blackstone labs returns showed only VERY slight coolant in the oil....and I kept changing my oil every 3K miles.

The good new is.....with the front cover gasket sealed.....and the new lower intake manifold gaskets in place....I have been in good shape for about 3 years now.
I STILL constantly monitor the coolant level in the cooling system......watching the overflow tank level and squeezing the upper radiator hose to make sure that it is full of coolant (if air can leak into the system.....radiator cap leak.....or other leak.....then the cooling system can get low...and not pull coolant in from the overflow tank to replace it.....not common....but I have had it happen)

I ordered the parts I need to change the lower intake manifold gaskets. Not all came in and only received the gasket kit and the sealants so far. the rest will follow. The gasket kit they send me consist of 2 silver colored gaskets with 5 holes, rectangle in shape, 1 gasket, black in color, has 6 oblong shape holes and all holes are lined up straight... Completely different from Wiswinds website pics which are thicker and the holes are round... not lined up straight... Maybe because mine is 95windstar 3.8L and my manifold configuration is different. I am hoping that someone in this site with a 95windstar, have done this procedure and share some inputs. I made a search and read most of the threads in regards to lower manifold gasket replacements, plus Wiswinds webshots which gives me an idea how to do the job. I copied and print your inputs and will use them as a guide. I am not a mechanic...my first time to go inside an engine. I've done power steering, water pump on my 91 taurus, plus igniton coil, plugs, wires and thermostat to my 95 windstar and that's about it. I should recieve the rest of the parts on monday and will start then. Thanks

The 1995 3.8L intake is MUCH different from all other years due to the IMRC system.
The 1995 did not have the IMRC and the other years do.
The IMRC system has 2 intake ports per cylinder......that merge into 1 in the head.

Make sure that the sealant is labeled "sensor safe" so that you know that it will not bleed off chemical(s) that will be harmful to the oxygen sensors.

Take your time doing the job, use no metal tooling (like a razer blade) to clean the gasket surfaces.....use wood or nylon and solvents, keeping the solvents from getting into the ports in the head.
Metal tooling will make scratches in the soft alluminum, which can lead to "weaping" of coolant past the gasket.

Also....I recommend using a BEAM style of torque wrench as "clicker" style can be hard to use a these low torque values......get a INCH pound wrench.....not a foot pound.

Of course, you must change the motor oil after doing the lower intake manifold gasket job, BEFORE starting the motor.

I want to note something that I forgot to mention.....so I will put it in its own post.
The 1995 3.8L......and ONLY the 1995 did have issues with the head gaskets failing.
The wall at a couple places put the coolant passeges close to the oil passages and the cyinder......which could lead to the coolant "wicking" through the narrow space.....leading to head gasket failure.
I would recommend, for this 1995, having a more in depth diagnostic done to verify the head gasket condition.

I would hate for you to go to the trouble of replacing the lower intake manifold gaskets.....only to have to tear it all apart again.
The lower intake manifold gaskets MUST be replaced whenever the lower intake manifold is removed.....so these gaskets are a part of a head gasket job.

I am not experienced in how to diagnose a leaking head gasket vs a leaking intake manifold gasket.......but if you had ANY other year than the 1995, I would put money on it being the lower intake manifold gaskets.....and the head gasket being just fine.
But....being a 1995 3.8L.....further investigation might be a good idea.

I have read that a test of the coolant for "combustion byproducts" is one way to determine if it is a leaking head gasket vs a leaking lower intake manifold gasket.....this would ONLY work for a leak between a coolant passage and the cylinder.....which could also be present (in other words....the coolant passage can leak to both a oil passage and a cylinder).

Some shops can be quick to point to the head gaskets when they are fine......the customer never knows the difference because the lower intake manifold gaskets are replaced in the process.....solving both potential leak points.

Wiswind, thanks again for your reply. The dealer repair shop replaced the head gasket at around 40K to 50K miles.. before the recall noticed. I was overseas then and my wife went for a 40k or 50K miles check. They informed my wife that it needs to be replaced because it will fail soon and I think she paid $450.00. I hope that the head gasket is still fine as of now. Does it light up a CEL if the head gasket fail? Right now I'm still waiting for the parts I ordered...the sealant gasket they gave me is silicone and does'nt say sensor free so I have to return that. I continue to read and understand the threads and pictures from this site since I am going to use it as a guide.Thanks