service engine light...HELP

[wiaka94]

We had our van serviced (they also replaced the drive belt)and the service engine light came on; than it would go off, it continued this behavior and we took it back to the mechanic, he replaced the belts, water pump, and tensioner. Now the light stays on all the time. We've taken it up to Autzone twice, the first time there were no codes on it. Then we took it back again and it said there was a link error, more . The clerk said it now is a computer problem. Can anyone help?

[DRW1000]

I cannot see why the replacing the drive belt should have started this.

I also can't see why someone would replace the water pump to try and correct a code they could not read. (especially since on some years it is a 6 hour procedure).

In any event you took the first step in trying to read the codes. Unfortunately if you cannot connect to the PCM to get the codes everything you do is hit and miss. I would ensure that you are getting proper voltage to the OBD11 port. My personal code reader will give me a link error if the 12 volts (and return) are not present. There is a fuse that controls this.

I assume you have a 96 or later van but I don't think you mentioned the year.

[cellguy030]

I had this light come on after getting my oil changed at walmart. shortly after my alternator went out. after i replaced it the light was no longer on. this could be the issue

[wiaka94]

Originally Posted by DRW1000

I cannot see why the replacing the drive belt should have started this.

I also can't see why someone would replace the water pump to try and correct a code they could not read. (especially since on some years it is a 6 hour procedure).

In any event you took the first step in trying to read the codes. Unfortunately if you cannot connect to the PCM to get the codes everything you do is hit and miss. I would ensure that you are getting proper voltage to the OBD11 port. My personal code reader will give me a link error if the 12 volts (and return) are not present. There is a fuse that controls this.

I assume you have a 96 or later van but I don't think you mentioned the year.

1997-98 Ford Windstar LX. We were finally able to get a code and we replaced the mass air flow, the guy at the Kragens said to not clear the code, it would clear itself after 30 starts or 300 miles it didn't. So we cleared it and we got another code PO171 meaning the left bank is running lean or there is a vac leak. My brother who works on his own Fords believes it is still the mass air flow. I do remember reading in here that sometimes the mass air flow can over compenate and read wrong; correct me if I am wrong. One question I have is why would this light come on after an oil change???
We really need some help our lic. is due in early August and we do not have much money. Oweing still $7000.00 and engine light problems.
Please, please help us.

[wiswind]

Do you still have the original MAF?
I have read that there can be issues with some "aftermarket" MAF units.

There are specific codes for MAF problems.....also.....the MAF can very easily be cleaned. I posted pictures of where to spray the NON-RESIDUE ELECTRONIC cleaner to clean it out.....http://community.webshots.com/album/201931518cScpNK

You also want to look for vaccum leaks....including making sure that the flexible hose that goes from the MAF to the throttle body is firmly seated on the throttle body, that the little groove in the top of the flex hose is lined up with the little notch on the top of the MAF.....that the stiff plastic hose that goes from the oil breather on the valve cover to the flex hose is firmly seated at BOTH ends. Also check the inside of the flexible elbow on the TOP of the Upper intake manifold......the connect to the line that goes to the PCV valve....mine developed a crack on the inside......and was leaking.

And.....make sure that the oil dipstick is firmly seated......The air that is drawn out of the Crankcase by the PCV is replaced by air that flows into the opposite valve cover through the breather.......which is air that is measured by the MAF......so a loose dipstick....would permit air into the crankcase.....that is NOT measured.

Vaccum leaks are VERY common problem on most any modern car. This is because the airflow into the engine is so closely monitored.

[nuclearaxemurderer]

to wiswind
Thanks for posting your picture link. My daughters car is showing the po171 code so I was online searching to see what I could find out about it. This thread came up and viola'. Your pictures are worth a thousand words but I only have a couple "THANK YOU"

axe

[wiaka94]

First I want to thank all of you in this forum for replying, and I want to thank the fellow that provided pics. I believe we have finally found the problem.
After we found out that there was NO PVC valve we replaced it. We took it to the smog place but while we were waiting to have it smogged the stupid light came back on. They ran an OBD on it and found an manufacture specific code. I jumped on the forum and we not only found the code but how to check the device and pics to locate the culprit. Turns out it was the intake manifold runner control on the left bank causing the problem. Hopefully replacing this takes care of the light for a long, long time.
Thank you everyone for your input.

[wiaka94]

Wiswind, I too am a webshots community member, your photos are great!
If you would like to see my photo albums let me know.

Originally Posted by wiswind

Do you still have the original MAF?
I have read that there can be issues with some "aftermarket" MAF units.

There are specific codes for MAF problems.....also.....the MAF can very easily be cleaned. I posted pictures of where to spray the NON-RESIDUE ELECTRONIC cleaner to clean it out.....http://community.webshots.com/album/201931518cScpNK

You also want to look for vaccum leaks....including making sure that the flexible hose that goes from the MAF to the throttle body is firmly seated on the throttle body, that the little groove in the top of the flex hose is lined up with the little notch on the top of the MAF.....that the stiff plastic hose that goes from the oil breather on the valve cover to the flex hose is firmly seated at BOTH ends. Also check the inside of the flexible elbow on the TOP of the Upper intake manifold......the connect to the line that goes to the PCV valve....mine developed a crack on the inside......and was leaking.

And.....make sure that the oil dipstick is firmly seated......The air that is drawn out of the Crankcase by the PCV is replaced by air that flows into the opposite valve cover through the breather.......which is air that is measured by the MAF......so a loose dipstick....would permit air into the crankcase.....that is NOT measured.

Vaccum leaks are VERY common problem on most any modern car. This is because the airflow into the engine is so closely monitored.