96 GL Vacuum Leak

Before I spend $700 - $800 to replace an intake manifold, as suggested by my mechanic for a vacuum leak, are there a few easy things to do first that may fix the CEL from staying on. (105,000 good miles so far)

Have your codes read.....you can have this done for free at some auto part stores.... such as Autozone. Get the actual numbers from them.
Then....post back with the numbers.
The '96 has a good upper intake manifold that is not prone to the problems that the '99 and '00 had. But pretty much ALL modern cars can have problems with vacuum leaks.

I don't know what your codes are, but in January 04 my mechanic found that my 98 Windstar CEL pain in the was being caused by manifold vacumn valve stuck open. He got some off another vehicle that matched mine, charged me $50 each and $60 each to put in. No more CEL. Hope that helps you. This forum is fantastic, I've only been in here for about 2wks. now (because of problems of course) and I've seen some pretty good suggestions. Keep up the great help guys. I can't believe there are so many REOCCURRING problems in here. Yes I can, I don't know why I ever bought a 2nd Ford, should have learned from the 1st on. After this one stops running (156,000 knock on wood),no more Fords for me that's for sure! Good Luck.

I may have posted a partial version of this question so, I'LL try again,

The codes, read at AutoZone are PO171 & PO174. Running Lean both sides. I put in a can of fuel system cleaner and the van ran a little soother almost immediatly.

Again my question is, is there a few things I can check out before spending 7 to $800.00 on an intake manifild?

This site is great!

The codes you posted indicat a vaccum leak. Which intake manifold did they want to replace?....there is an upper intake manifold.....which is the big black one....and the aluminium "lower" intake manifold. The '96-98 is NOT as problem prone (intake manifold wise) as the newer ones. The Bolts and seals are fine....you might want to make sure that the bolts are tight...but the torque specs for them....is not real tight....so don't over-do it.
There are a LOT of places for a vaccum leak to happen. Basically.....this can be at ANY point that air enters the intake PAST the Mass AirFlow sensor (MAF). The PCV air is measured.....that is....the air going into the FRONT valve cover (on the '96) to replace the air that is pulled out through the PCV valve....which enters the front valve cover through a stiff plastic hose....that goes to the flexible hose that goes from the MAF to the throttle body. There are a LOT of vaccum connections on the back of the upper intake manifold.

I DID develop a leak in the flexible elbow that is right on top of the upper intake manifold......next to the throttle body. This is the line that goes to the PCV valve....which is on the back valve cover. Was a little crack on the inside of the elbow. Also....make sure that the PCV valve is inserted into the back valve cover.....

I like to cover the "cheap & easy" before spending any big bucks.....and my advice tends to be along those lines.....As very often....I have found that to be the case.

Thanks Wiswind -
I will check those things out and repost. It is the upper manifold that is being recommended for replacement and the bolts look easy. Is there a chance of O2 sensor malfunction on this? It seems this should be relatively easy to check.

I also replaced the air filter, which I could easily see light through, but dusty nontheless, and added the gray STP fuel system cleaner. The van seems to run a little smoother, but I am not imune to the placebo effect here. Since it is easy and cheap to do this I did it and it sure doesn't do any harm.

A question I have though is if, I am running lean wouldn't that affect the mileage? I have not seen any change and pretty consistently get about 350 miles to a tank and have since the car was new.

Thanks Again

I have yhe same problem on my 95 Windstar wit 186T miles. SES light is on with codes P0171 and P0174. System too lean Bank 1 and Bank2. My mechanic cleand the injectors, changed the fuel pump, put a new gasoline filter but the codes will come up again. I also read in some treads that the MAF sensor could be dirty and have to be cleand. I cant find a air leak..

The '95 has a different upper intake manifold.
The '96-'98 use basically the same upper intake manifold. In '99, they went to a different upper intake manifold again....which has a number of problems that the '96-'98 do NOT have.

I would wonder why they wanted to replace the upper intake manifold....unless is was physically broken.

Having the fuel injectors professionaly cleaned is something that you could try.....as well as the fuel filter.

Cleaning the MAF sensor is another step.....Non-residue electronic spray cleaner would be used for this.... The MAF sensor is right next to the air filter......when you release the buckle....you have the air filter assembly on one side.....and the MAF on the other. Looking in from the air filter side....you will see a screen......in past the screen....you will see a plastic "bar" that goes across the bore of the opening. Look closely at the this "bar" and you will see a small hole. There is another hole on the other side of the bar.....at the other end of the bar. Air flows in through the hole that faces the air filter.....and out through the hole that faces away from the air filter. Inside are 2 thermal sensors..... This is where the actual air flow measurement takes place. When you spray the electronic cleaner....you want it to go in one hole in the "bar" and out the other.....thereby cleaning the MAF sensor.

IF you go to www.Autozone.com you will be able to look up vehicle specific repair information.....and they will show you the torque specifications and sequence for the 12 bolts that hold the upper intake manifold down to the lower intake manifold. Do NOT overtighten. This upper intake manifold does NOT have the issues with the bolts and gaskets that the '99 and newer ones do. If you do decide to replace the upper intake manifold gaskets....you can get them through www.rockauto.com I would be surprised if there is anything wrong with the gaskets.....is possible that the upper intake manifold bolts could be loose.

Vaccum leaks are very common....as they are on almost any newer car.

Oxygen sensors have been replaced quite often for a variety of issues......most often does not clear any problems. You have 4 oxygen sensors. One before and one after for each of the 2 catalytic convertors.

Thanks Wiswind this is good information. I am preparing for a snowstorm in Chicago area and might not be able to get to this right away but will look at the MAF, vacuum hoses and PVC attachement. I don't have a torque wrench but maybe able to rent one for this check. At one time I had a calibrated "Touch" with that sort of thing but that was too long ago. Also, good information about AutoZone publishing specs. I picked up the Haynes Manual and will compare.

Again thanks for your input and all the rest who have posted in this thread.

R Webb

Sears has a 3/8" simple beam-type torque wrench for approx $20. I had one for many years... does the job.

I torqued mine by hand.....The torque specs are in INCH / LBS.......not super tight....the bolts are not very thick.....and they are going into aluminum.
I have a torque wrench that I use for my lug nuts.....it does NOT go low enough. In other words.....the lowest setting would result in overtightening the bolts......and breaking something....or stripping the threads in the lower intake manifold.....
The intake manifold has NO moving parts....and NO baffels that are prone to break loose.....as it seems that the newer ones seem to have.

Here is a link to a few pictures that I took of my '96 3.8L. It might help you find your way around. Mine has over 145K miles on it.
http://community.webshots.com/album/201931518cScpNK

I am in Milwaukee......and this information is for the SE Wisconsin Northern Illinois areas that use the EPA mandated "Reformulated" or "Oxygenated" gasoline. We use a special blend that is ONLY used in these areas. This past fall.....when we went from the summer blend to the winter blend.... There was an increase in the number of people showing up at service centers with clogged fuel injectors...... There was a story in the Milwaukee Journal-Sentinal that stated that the problem lasted into December. I do not remember the exact percentage....but it was something around 75% of the cars that had problems were GM products. GM investigated....and found that it was caused by some sort of crystals from sulfur in the gasoline.

I have read that the EPA requirements (talking the whole country now) for detergents in gasoline are not real high considering the small clearances that fuel injection cars have. There are some companies that promise the have an increased level of detergents.....a voluntary program. The gasolines that meet this level of detergents.....are called "Tier 1 gasoline". To be Tier 1. A company must have this standard at ALL of it's stations, ALL grades of gasoline (not just premium). Periodic use of a good fuel system cleaner is something that I have read that one should do. Not all fuel system cleaners are created equal.....so get a good one.
Problem is.....that this problem can slowly creep up on you over time....so you don't notice it until it is pretty bad. I have been using Redline Complete Fuel System Cleaner.....available at Advance Auto Parts. I have also read good things about Fuel Power.....available online at www.fuelpower.com
Another brand that I have read good things about is Chevron Techron. I am sure that there are other good brands.

This past summer (well before any gasoline problems), I developed a very slight miss. No CEL.....I was chasing the problem for quite a while......and finally it got bad enough to light the CEL. I had the codes read, and it was a missfire on cylinder #1. I had just cleaned the EGR ports a few months earlier......and checked them again......and the EGR system was fine. I pulled the spark plug from cylinders #1 and #2....and compared them (the plugs were 4 months old). They were fine....but cylinder #1 was much cleaner. I put the plug from #1 into the #2 cylinder.....and the #2 on in cylinder #1. I had new plug wires, coil pack, Camshaft Position sensor, EGR valve, DPFE,....and so on. Anyhow.....I cleared the codes.....and the next time the light came on......I had the codes read. Still missfire on cylinder #1. So I bought a new fuel injector......When I removed the fuel injectors.....I found my problem. I had run fuel system cleaner several times a year....but I still had a buildup....not IN but ON the output of the fuel injectors. The injector seats into a plastic "cup" and then into the lower intake manifold. The plastic "cup" on each injector had a buildup of crud in it. I was able to very easily remove it with a shot of "carborator" cleaner. This totally solved my slight miss. All the injectors had the crud inside the cup....it just so happened to cause a problem with one cylinder before the others. The Fuel injectors are mounted into the lower intake manifold. I had to remove the upper intake manifold to get to them. Also, the instructions that I was following said to remove the fuel rail....then the injectors.....but failed to mention the clips that hold the injectors to the fuel rail.....so they all came out when I pulled up on the fuel rail. Was not a problem.....however...you MUST be careful to avoid getting the crud that WILL be built up in the little recess in the lower intake manifold....around each injector.....

wiswind
You are right about a torque wrench being useless if its not of the correct range. The torque wrench you use for wheel lugs is probably a 1/2" ... and has a range of something like; 0 - 150 ft-lbs. I have one of those. My 3/8" beam wrench has a range of 0 - 50 ft-lbs and 0 - 600 in-lbs....its graduated in both units. The "in-lbs" scale is incremented in 25 in-lbs ...not as small as I would like, but better than nothing. I have not found a cheap 1/4" torque wrench .... that size would be ideal.
I believe I remember the recommended torque for the ('99) intake manifold being 10 newton-meters...or 7.37 foot-lbs...or 86.51 in-lbs.

Here is an interesting site for "torque conversions",
.
http://www.pitt.edu/~rsup/touqueconv.html
. Just type in a value in any unit field and push the button.

Those are good intake manifold photos... thanks for the info.

You've got me wondering about my injector base cups... gonna check that out soon. Thanks again!

My 1/2" torque wrench for the wheel lugs...is one of the "click" types....clicks when you reach the torque setting. It does NOT go down to zero.
It was not real expensive.

Thanks for the feedback on the pictures. Not being a mechanic by trade, I find it helpful to have an idea of what I am getting into before starting the job. And I LOVE pictures.

Well I started this thread on January 10 asking about vacuum leaks and not wanting to spend 7 to $800 on a new intake manifold. As it turned out wiswinds response on 1/20 was the correct solution - clean the MAF sensor in front of the Air Cleaner. Cleaned it, the CEL went out, went to get tested and failed the gas cap check - result saved the dough and lost the old mechanic with the expensive solutions.

Thanks for the insight and all the other information in this thread!

AF Enthusiast I have noticed that you are very thorough in your post. Are you a Ford Mechanic? Hope you can help me with this one, otherwise I think I'm gonna have to go to the dealer, and I hate having to do that. I have post several issues I've had with my 98 Windstar 3.8., but have had one that I just can't find an answer for, so I hope you might be able to help. Like I said, I have posted this before so it might seem familiar to you. "I posted a msg. a while back on this problem. I thought I had a fix when I took my 98 Windstar 3.8 to the mechanic I've used for over 7yrs. He's been pretty good on other problems I've had and seen in this forum, but this noise issue really has him puzzled. He did the following due to squeaking noise when turning left (also worse when eng. cold, gets better when eng. warms up (like yours mom4two), unless weather is real cold during day then doesn't improve at all)& knocking on right side when moving from a stop : 10/00 changed struts; P/S pump; (fluid was black), 10/02 right rear motor mount; 10/03 ball joints; both outer tie rods & sway bar links; 12/04 right c.v. joint, right front motor mount, sway frame mount; and 1/05 break pads, greased struts again per post I told him of, flushed p/s fluid (dark not quite as black as before). WHAT'S LEFT?"
Well that's it in a nutshell, have any ideas? Please help me OB1Kanobi, your my only hope! Just kidding, gota laught to keep from going crazy with this thing. Thanks.

I am not a Ford mechanic....I just noticed the "AF enthusiast" next to my name.....It must change to that after a certain number of posts.
I use my windstar to haul kids in my volunteer activities.....and don't want to have problems 500 miles from home on a mission trip with a van full of kids.......... So I have done a LOT of reading on the internet...to try to keep the major car disastor for the trip limited to cleaning paint out of the interior.

Try doing a search under "front end clunk" to read about a few ideas that are posted.....I have not had the problem you are describing...other than having the subframe pockets re-welded for the clunking......

Thanks for the reply. I went in with the search you recommended and found some post I had not seen yet. I printed them and will discuss them with my mechanic. Thanks again for the advise.