Spark Knock

My Windstar has developed a pretty significant spark knock on acceleration. The engine does not run rough and a full tuneup was done to no avail. It has 95000 miles on it could the timing be out of whack without it running rough? Could it be a bad MAF sensor without sending a trouble code? Any ideas thanks

Hello

It sounds like your EGR ports may be getting pluged. The engine may not be getting enough recirculated exhaust to slow the conbustion of the gas.

I would pull the upper manifold and clean the EGR ports. The gaskets are reuseable. It shouldn't take too long and isn't that difficult.

Also...read the links in my signature they'll help you out a lot.

Regards

Dan

If you do pull the manifold, do some more searching on the P0174 code as there is a posting explaining in detail how to complete the work and which parts need replacing, i.e. the isolator bolt grommets. The manifols gaskets are re-usable, but if you have the old black style grommets, you need the new green ones. You can clean the EGR ports at the same time as it takes no more work to get to both than it does to get to one of them.