2002 Engine Light On - Does this sound right

[starwin02]

Engine light came on - repair shop diagnosis was code P0316 (misfire). Repair shop replaced ignition wire set 6 cylinder and stated light may come back on if I don't replace platinum spark plugs and fuel filter - fuel injection and get a uny 3-step fuel system cleaning. Light came back on in 3 days. Vehicle has 63,000 miles. I took it to another shop and they said that didnt seem right. It may be 02 sensors. What should I do?

[rodeo02]

Definately sounds like the isolator bolt, leaky port seal or clogged EGR jet(s) issues that crop up on the 1999+ windstar 3.8L. You probably have a severe vacuum leak causing a misfire, or too much EGR in the cylinder that is misfiring. Not too awefully difficult (or $$) of a repair. Search this forum for the details on those issues.
G/luck
Joel

[DRW1000]

Not to doubt you Rodeo but would we not be seeing a 171 and/or 174 if there was a vacuum leak?

Starwin,
I think we need to look at what causes the misfire code. (are you certain it was P0316?)As far as I know this is caused by an instantaneous drop in the engine RPM indicating that a cylinder is not fully contributing to the rotational speed of the engine.

The cause of the misfire is now what we try and interpret. When you pay a mechanic you are really paying for their expertise. Sometimes they replace a few components to try an save you some money and it does not solve the problems and they look incompetant and other times they replace everything they can think of and you get a huge bill and the problem goes away. They could also replace a lot of items but be wrong and that gets the customer really upset and they look really incompetent.

I think the cables, plugs, filter and perhaps even the fuel system cleaning were not bad ideas as they are maintenace items anyway. The fact that it did not solve your problem is frustrating but I don't think they were a complete waste of time - just parhaps a bit pre-mature due to only 63K.

I would not tend to blame the O2 sensors just yet

I tend to agree with rodeo02 that the EGR ports may be clogged. This is a known issue in 1999 and up Winstars (3.8L). In this instance there are 6 1/8" ports inside the intake manifold for EGR flow. They clog due to oil in the manifold. When some but not all clog it tends to route more EGR flow to some cylinders and it causes misfires. Unfortunately the only practical way to check is to get to the EGR ports and they are in the intake manifold.

Clogged EGR ports are the result of a major desgin flaw. Usually other codes are involved too. The fix is to follow a certain TSB-03-16-1. This TSB also covers cleaning the EGR ports.

Rodeo is correct in that it is not a difficult repair or too costly and if you can do it yourself even better.

All of the information is here in this forum.

[starwin02]

Thanks rodeo02 and drw1000 for your responses. I really appreciate it. I have already been out over $1000 on repairs so I am trying to make sure what NEEDS to be done gets done. I did get a little more information after speaking with the mechanic...the P0316 code was cleared after the ignition wire set was replaced. Engine light is back on and the vehicle history is showing codes 171 & 174 system running to lean....what should I do next (least expensive method)? Mechanic wants to replace platinum spark plugs and fuel injection filter and do a 3-step fuel system cleaning, is this necessary?

[wiswind]

I have a 1996 3.8L windstar with over 140K miles on it.
The older windstars....like mine....are prone to EGR port clogging.
I have cleaned mine.

The slight miss issue is very common.....and can be difficult to track down....
This is because there are so many things that can cause it.

When my EGR ports clogged....I got a missfire code for cylinder # 4.
The other ports were clogged....and most of the EGR flow went to that cylinder's port.....and caused the missfire. This is the ONLY code that I got. I had replaced the double platinum plugs about 2 months before that.

If you have a miss.... And suspect that it might be a EGR issue.....
1. Locate the vacuum hose that goes to the top of the EGR valve.....
remove and plug it. This will disable the EGR valve from opening.
2. Drive the car.....If the miss is gone....you most likely have clogged EGR ports. ....and they will need to be cleaned....You will want to clean the ports and reconnect the hose.
Please take note that you may get an additional code due to lack of EGR flow whith the EGR system disabled.

A sticking EGR valve is listed as a possible cause of misfire....but seems to be less likely from what I have read on posts here and other places.

Check for vacuum on the EGR valve hose (the one I instructed you to remove). There may be a very slight amount of vacuum....is OK....
But if there is signifcant flow....the EGR Vacuum Regulator solonoid may be sticking....you can spray some 'Sea Foam' into the hose....to clean the solonoid. The EGR Vacuum Regulator solonoid is located on the back of the upper intake manifold on my '96.....you cannot see it...but can follow the hose....and feel it. It may be located at a different place on your 2002...as it has a different upper intake manifold......but you WILL have one. The EGR Vacuum Regulator Solonoid....has an electrical connector that takes an electrical signal from the Computer....telling how much EGR flow is desired....and converts it to a vacuum to the EGR valve. There is also a EGR flow sensor.....called a DPFE (Differential Pressure FEedback sensor)....that has 2 hoses going from the metal pipe that goes from the exhaust manifold to the EGR valve. The difference in pressure between these 2 hoses is proportional to the flow of exhaust gasses through the EGR system.....the DPFE will change this pressure difference to an electrical signal.....and send it to the computer.

Your spark plugs are rated for 100K miles....if all goes ok.
When you have them replaced....have ONLY DOUBLE PLATINUM installed.
As far as I know...only Motorcraft and Autolite have them.

Fuel system cleaning. I did have a slight miss.....finally got bad enough to illuminate the Check Engine Light (CEL).....and I had the code read at autozone (free). I had replaced MANY things prior to this trying to track it down (I figured that I could throw parts at it myself cheaper).
Root cause of my problem was a buildup of crud on the output side of the fuel injector. I found that all of my fuel injectors had this.....even though I kept clean fuel filter and ran fuel system cleaner on a regular basis. The solution was to spray a bit of cleaner on the end of each injector to flush it off......That is...after removing the upper intake manifold...and the fuel injectors to get to the ends of them.
I am told that this is normal for any fuel injector with many miles on it.....The atomized fuel hits the PCV gasses and EGR gasses and the crud is created. I was able to further diagnose by pulling the #1 cylinder spark plug....(the cylinder that was giving me the code this time) and compare it with a plug from another cylinder.....the failing cylinder was cleaner....an indication that it may not be getting as much fuel.

Newer windstarts (Post '98 with the newer upper intake manifold) have a TSB (Technical Service Buletin....NOT a free RECALL) regarding vacuum leaks caused by upper intake manifold gaskets, and bolts....also a replacement valve cover with an improved baffel to reduce PCV liquid (oil) from spraying by into the intake system.

ALL newer cars are subject to pesky vacuum leaks.
Also....The Mass Air Flow sensor (MAF) can become dirty....spraying some non-residue electronic cleaner into the little holes to flush it out will help there. The MAF has a screen.....and a plastic cross piece with a hole in the side facing the air filter and a hole in the opposite side.
The air flows in one hole....and out the other......in the process....it flows over 2 thermal sensors. 1 is heated to maintain a constant tempurature...and the other measures the tempurature....The current flow to maintain the tempurature is proportional to the air flow into the engine.....compensated for the tempurature......
Bottom line....dirt will cause a incorrect reading....and problems.

[DRW1000]

StarWin,

The TSB I mentioned earlier is just for the P0171/174 codes. Do a search on these codes and you will find hours of reading entertainment. Post back for anything you do not understand.

If you are handy with a wrench you may consider doing the work yourself.

[starwin02]

Thanks for the responses. Quick question do you think replacing the ignition wire set was necessary and should I allow Goodyear to replace the spark plugs (63,000 miles - 2002)?

[DRW1000]

I think the ignition wire replacement was a bit premature but they were trying to correct a misfire so I know why they might have tried it.

I think the plugs should last 100000K. Since the misfire is gone I would not bother just yet. When you do replace them ensure you use double platinum plugs