Hot Rod Forum : Hotrodders Bulletin Board

Hot Rod Forum : Hotrodders Bulletin Board (
-   Transmission - Rearend (
-   -   windstar trans/motor problem (

bentwings 04-09-2004 05:51 PM

windstar trans/motor problem
I searched the knowledge base but got nothing so here goes.
I have a 98 Ford Windstar 3.8 w/elect od. Initially it had some kind of mis fire on 1 and 4. (scanner)I replaced the coil,plugs and wires. This seemed to help for a day or so. Now I was driving down the road about 45-50 and down shifts from od to 2nd gear!! WTH is going on. So I get back up to speed again and pow it does it again. It's just like I shifted it manually down to 2nd except faster. Then as I am at a lower speed it starts hunting between 2nd and od. needless to say it's got to be tough on the trans. I had the trans just break right in rush hour traffic about 2 years ago. 2500 bucks for that one. At least I was able to back traffic up for a mile or so. LOL. Anyway on the way home at about 30 mph it is constantly shifting up and down.
anybody have any ideas???

dmorris1200 04-09-2004 06:09 PM

A bad MLP (Manual Lever Position) Sensor will make those trans do some weird things. On that trans I believe it sits right on top of the trans. Looks like a fancy neutral safety switch, which in a way it is. It tells the PCM what gear your selector arm is in. When acting up it can let your computer think you are manually shifting into different gears while you are driving. A good scantool can monitor the output voltage of this sensor while driving. Just one of many possibilities, but I have seen them go bad on those Fords. Best thing unfortunately may be to have a qualified trans technician look at her before serious damage is done.

airworld2 04-09-2004 11:33 PM

demorris is on the right path replace mlp switch also replace speed sensor, windstar has exhaust too close to speed sensor heat cooks it way too often, shield the new sensor with heat wrap of some sort or you will replace the speed sensor every few month's.

ohh by the way its a bear to get too......

dmorris1200 04-10-2004 07:02 AM

Re: windstar

Originally posted by airworld2
ohh by the way its a bear to get too......
Oh man, you aint kiddin'. Good call, almost forgot about the VSS. If I remember (it's been awhile) I used to remove the rear two subframe bolts to drop the back of the subframe then reach up in there and remove the sensor. Not a fun job. :mwink: :D

bentwings 04-10-2004 09:56 AM

thanks a pile guys
Thanks for the tips. I've suspected the trans for a while but I had to go after the plugs,wires and coil first. This problem and motor tune problem has been plaguing me a month now. Unfortunately all the trans shops are closed this weekend.
Will the OBD 2 pick up trans problems like this.???
I can hustle over to the "Zone" and have them scan it again. I also looked around for a scanner of my own. O'Rielys has one for around 200-300that is supposed to do it all. They claim it will also work on my 99 Dodge diesel so I could justify it that way.
thanks again guys. If this gets fixed I can go back to work on my Willys.

dmorris1200 04-10-2004 01:03 PM

A code reader will do you no good unless you have a 'check engine' light on. A sensor can still give innacurate readings without setting a code. A trained tech will monitor 'live data' through a good scanner and watch for irregular sensor outputs to the PCM. If you can get live data and a manual that gives proper sensor outputs you may be able to catch something yourself.

bentwings 04-10-2004 06:59 PM

check engine lite
There is no doubt about the "check engine lite" It's been reset about a dozen times by a couple shops. I think you are absolutely right about the real time thing. A couple things stand out in your post which have been nagging me too. one is the "trained" the other is "good...". The local shops are reluctant to ride around untill something happens. time is $$. It's been a good long while since I worked in the auto shop and spent time in the auto classroom. In fact there weren't computers especially in cars so we had to rely on experience, repair manuals, symtom lists, and hands on fixin', and most of all road tests....sometimes taking the car over night. I have the greatest respect for the computer and especially the concept of the computer making "inaccurate" readings. I'm sure there are reasons but sometimes you have to rely on gut feeling and experience regardless of what the "sensor" is saying (sounds like Scotty and the Enterprise). After all it is still an IC motor and an automatic controled by electronics instead of "inferior" mechanical devices. Nevertheless the controls are there and we just have to adapt to how they work and perform.
What is y'alls recommendation for a scanner?????

An acquaintance is a builder in a trans shop so I'll hit him Monday. If this doesn't work I'll have to get a scanner and start a "fishing trip".
Have a good week end and thanks for the help.

crazy larry 04-10-2004 07:49 PM

Bentwings, i bought an auto xray scanner, its ford specific, but i can upgrade to gm chrysler foreign etc, just $$$ is all..... it's for the obd1, it does moniter real time functions, i love it. there's a good thread, " whats your favorite scan tool and why?" in the lounge i think, i'll see if i can find it....
don't forget to look on ebay, thats where i found mine.......

(i just figured DMorris was tired of me warting him all the time, so i went and bought one.:mwink: )

scan tool thread

dmorris1200 04-10-2004 09:13 PM

Heck Larry, never get tired.:D Most of us are here simply trying to help others out. Unfortunately with this type of stuff it is much trickier. Would be much easier if it was a neighbor and I could simply hook my scanner up on a Saturday afternoon but this is the Internet and we are forced to try and guess and rely on previous failure patterns sometimes. If you could find someone willing to spend a little after-hours time with you for some cash that would be great. Basically the scantool allows you to monitor what voltage the PCM is seeing from the MLP while you are driving. During a glitch you would need to be able to 'see' the error. For example it may output 3.45V when your selector is in OD but while driving if that voltage dropped to 2.25V the PCM would think you just manually shifted gears. These are made up values as I don't have service manual info for your car. In the same manner the VSS (Vehicle Speed Sensor) may be sporadically loosing it's signal. The PCM may think you are doing 35MPH when you are actually doing 50MPH and it is trying to downshift. You could guess and replace the MLP or VSS but I hate to see people spend money on a guess. This is the main thing that keeps me away (usually) from this type of situation over the Internet because I hate to feel responsible for anyone wasting their money on a bad guess. I hope you get a break soon somehow and get her fixed to let us know the fault. If you have questions as to how something works feel free to ask. We can tell you what any sensor does but finding a bad part over the Internet unfortunately is a bit more difficult. Happy Easter anyway. ;)

PS. Just an add-on to give you an idea of what you are dealing with over a trans problem. A buddy of mine had a late model Explorer that would neutral out every time from a stop in Drive. If you manually shifted into 2 it would start off and then you could upshift into drive and she would shift right up into overdrive and lock up the converter like normal. As soon as you came to a stop she had to be shifted back into 2 again 'cause she had no first. The first three places he took it to told him he needed a trans and quoted him a few thousand dollars. Convinced it didn't need a whole trans (only 47,000 easy miles on her) he kept trying and the forth guy he took it to had this little two bay trans shop, nothing fancy and privately owned. The guy fixed it for a few hundred dollars and sent him happily on his way. I have witnessed guys misdiagnose transmissions that only needed a sensor for something because they just aren't trained right (at dealerships and independents) or can't spend the time on her like already mentioned. Unfortunately it is often easier to just say "needs a new one" than to repair her. My friend gave me that guys name and his shops phone number so I will have it. I checked around and apparently this guy holds a very good reputation. When I find an honest reputable person like that I keep that info handy for future reference.

PSS. To our transmission guys here at hotrodders do not take that last paragraph as a bashing on trans guys (I mentioned dealerships and independents not acting professionally) as I have seen just as many poorly trained engine mechanics as well selling bucketloads of engine parts because they couldn't find the problem the first time. Seems to many companies today just don't want to invest in well trained technicians for all types of repairs. Just my opinion.

bentwings 04-11-2004 06:34 PM

nasty problem
thanks for the info again dmorris and larry. I agree on the long distance analysis both on the receiving end and the giving end. You are very wise on the comments. As you pointed out it is tough to find someone who will really try to hit the thing needed to fix the problem rather than the "fishing trip" or just replace everything and wind up with a big unnessary repair bill.
When I worked in the auto shop in the 60's the only real diagonistic tool we had was an oscilloscope better known as a "scope" It took a good deal of experience to pick out ignition and motor problems with them. We all spent a lot of after hours time looking at cracked dist caps, damaged wires, fouled plugs. We also tested our own cars as well as any other problem cars. After a while you could spot individual problems pretty easily and "it misses when it's cold/hot" or it has "lost power" or "not running right" were common problem we fixed without running up the "fishing trip" repair bills. "We were a small shop as you noted but had a good list of return customers.

Now that you mention the VSS (vhicle speed sensor) this was replaced last fall when I had the wheel bearings fixed. yes a front wheel bearing actually did go up in smoke and noise. I think the original VSS may have been damaged during the repair. Anyway it was replaced. Funny how a few questions will jog the memory. Anyway I'm going to hit the trans shop Monday. I'll fill in what happens. I have 2 other trans shops to go to also. All offer free or low cost testing.


bentwings 04-16-2004 10:27 AM

once again
Hi again
Well 2 days in the trans shop and the problem is still there. I spoke at length with the mgr who personaly tested the van for the better part of 3 hours each of 2 no charge. He agrees that the trans shifter sensor (MLP forgot it's term.) can be faulty and not give a code as well as the trans speed sensor (VSS term.?). He said he would replace these but he feels there is a motor problem that should be addressed first. He also said he didn't want to get into replacing parts just because of gut feelings. This just gets into unnecessary repair bils. The trans tested excellent throughout all of his tests...infact as good as any he has seen. He said he really doesn't do motor tune up and only has code equipment which does trans specific and motor as it applies. Here are the codes that came up:
po 301 cyl #1 mis fire
po 304 cyl #4 mis fire
po 1513 imrc bank 2 stuck closed
As he said he wasn't into motor tune and said he didn't have a list that indicated the po 1513 code.....any ideas??

this sounds ominous...
how much are these things?

It sounds like I will have to take a short (expensive??) fishing trip and hope the h....l I don't catch any carp or gar (I live in the south) LOL It would be nice to land a Walleye but they are rare down here if y'all know what I mean. more likely gd catfish

I just got a sheet of .018 ss steel so I can fab a nice heat shield (as noted) too. It TIG welds great if you use the right filler.

so ya don't have to re read I have done plugs, plug wires, coil, air cleaner, fuel filter (twice), new batt, 4 tires, I even washed it. Muff shop says the muff brgs will last another 100k and stop pulling their chain LOL.

I gotta get this fixed ...d... it The Willys is crying over's motor is silent, the rad is cold, dust is gathering on its body, it is wailing because I haven't given it's weekly due ($$$).

thanks for all the help.

dmorris1200 04-17-2004 06:24 AM

Well unfortunately I don't have access to any manuals here but if you have a cyl. 1 & 4 misfire and have already replaced coil pack, wires , and plugs I can only think of a couple of possibilities. One possible would be a module. One other thing I've seen but only with certain manifold styles (can't remember yours) is where the EGR valve is bolted to the intake and uses passages through the intake for EGR flow the passages become partially blocked causing too much exhaust to enter certain cylinders causing a misfire in those cylinders under light acceleration. If I'm not mistaken cyl. 1 & 4 might fire together (they usually fire cylinders in pairs) so their may be a connection there (head gasket). In a dual-fire system if one cylinder is bad it will sometimes cause a misfire in the cylinder that fires with it. Ford also uses a set of butterflies in some of their intake that open under hard acceleration. I believe the IMRC stands for Intake Manifold Runner Control. These are usually seen looking at the front of the engine from the passenger side of the car. They look like a small vacuum diaphragm in front of each head (they could also be at the rear of the head). They also have been known to fail here and there. Bank 2 'should' be the front bank (cylinder head), emphasis on should be. Ford calls them left and right IMRC and even though right should be the rear head it is actually the front head on most IMRC listings. I think these are fairly inexpensive and easy to change. Maybe removing the upper intake plenum, giving the intake a good cleaning, check the lower intake for possible EGR passages and cleaning if there (we used to use pipe cleaners), new gaskets and a look into those IMRC valves might not be a bad idea. As far as the trans goes, the MLP sensor is the easiest to replace and sits right on top of the trans. If you ever replaced a neutral safety switch you can do it your self. The new one should be set to line up in either Park or Neutral when installed just like a neutral safety switch. Hope this is helping, any more info let us know. Don.

bentwings 04-17-2004 12:49 PM

I chased down the IMRC and found the vac motors I guess you would call them and moved them by hand . The back side one (bank 1) moved freely however the front one (bank 2) seemed to stick at about 1/4 in travel. I wiggled it around a bit and it seemed to free up. The test is to apply vac to the ports on the vac motors but I diddn't have any tubing the right size. (Later today) I think the Zone has these. I also found more oil inthe rubber belllows to the air cleaner. I wiped it out again and sprayed elec contact cleaner (not carb cleaner) on the sensor in the bellows. Hope that's ok. I started the car and let it warm up and it seemed to run ok. I feel a very slight unstableness in the idle. I put it in drive and set the e brake and stepped on the foot brake and floored the gas. It pulled pretty good and didn't miss so maybe the problem is gone temporarily. I really suspect this IMRC so I'll vac test it alater today. My wife needed the car again today so she drove off early this morning. She said it ran the best it has run in a month. Maybe those 2ndary shafts are the problem. I'll shag after them later today when she gets home.
thanks again for all the help. I really appreciate it. I'll post a summary of all this so it will be in the archives. Maybe I'll get to work on the Willys for a while today.

dmorris1200 04-17-2004 01:46 PM

I don't think those IMRC valves cost that much. Probably not a bad idea to replace it. It should have a small 'R' on it to designate it is the right IMRC, the left one has a small 'L' stamped on it's mounting bracket (usually). If it failed before it will most likely fail again. In you intake duct by your air cleaner is your MAF sensor housing. The sensor itself is usually removable on Fords with a tamper-proof Torx socket (tamper-proof Torx screws are like regular Torx screws but with a nub in the center so a regular Torx socket won't fit). If you remove the sensor itself from the housing it is cleanable with regular carb cleaner and we usually blow them dry with an air gun after cleaning. A clean MAF will do wonders for an engine. Make sure you have a new PCV valve in her to witch will help reduce blow-by from getting into the intake tubing. I would still consider removing that upper intake plenum, you should be able to do it with a basic manual and hand tools. This will allow you to examine the lower intake ports and check for those EGR passages, do a little cleaning, and replace the plenum to lower intake gasket which are notorious for causing vacuum leaks when they get old. You should be able to remove the upper plenum with the throttle body still attached to the upper plenum on most cars, you just need to disconnect any linkage, vacuum hoses, etc.. Keep us informed.

bentwings 04-17-2004 10:14 PM

This sounds like a fine thing to do on a rainy Saturday. LOL I'll go over to AZ in the morning and see if they have a couple of the IMRC servos. I'm sure I have enough tools to do the manifold so I'll pick up what ever gaskets are needed and plan on taking this apart. I have to do it soon or it will get to blame hot out side and my Willys has flat told me he is not sitting out in the hot sun while I play nursmaid to the van.
My wife said the van ran ok this morning when it was cool but acted up later . It didn't down shift like it has been but she said it did lose power but not as bad. I think the pointer is settling in the area you suggested...the mainifold EGR passages and these intake manifold runnner controls.
I sure do appreciate all of the help. I'll keep you posted.


All times are GMT -6. The time now is 12:06 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.