1999 3.8L Windstar knock/ratrle under load

[LTDzak]

Hello, have not been on this forum in awhile. I have a '99 Windstar with 109 K miles, bought it with only 7 K on the odo and have taken pretty good care of it (regular semi or ful synthetic oil changes).

For the last 30 K miles or so the engine has developed a rattle/knock when under load and fully hot. At first I thought it was spark knock but a couple of tanks of 93 octane gas made no difference.

In the archives for this forum at least one person found that a suspected rod bearing problem was really a lifter alignment bar breaking. I would think that this would make noise all the time.

Is there any possibility that this could be the intake (broken plastic manifold internal)? I had the TSB done under extended Ford warranty for the intake at 60 K.

I ordered the rod bearings today at the Ford dealer, $9 list per half for a 2004 designed bearing, they were cheaper at NAPA (14 for pair) but I wanted the latest design. Also picked up an oil pan gasket.

Has anyone done this? Are the rod bolts reusable? What else could this be? Thanks for any info, I will post notes & part numbers as I do this. LTDzak

[LeSabre97mint]

LTD

I replaced the rod bearings on my 95. I had rod noise on start up. The upper half of half of the rods were showing copper. Copper = bad. That was at 177xxx miles. I now have 240,000 on it. It has a slite noise on start up but not too bad.

I reused the rod bolts. However, I was reading the book (a few years later)and they say replace them.... Your call. Make sure you get the tab on the insert into the slot on the rod and cap. Don't mix up the caps. Make sure you use a torque wrench. Keep things clean. You'll have to rotate the engine to get to each of the rod caps.

Regards

Dan

[LTDzak]

Dan, thanks for the reply. Makes me sort of question whether the source of the noise is in fact the rod bearings, as it is quiet on start up.

Drove it today paying more attention - it seems to do it the most under load in second or (especially) third gear at relatively low RPMs, 1500 to 1800 or so. At times it is almost imperceptible, at other times it can be quite loud 9 especially with a very warm engine, on the highway or after just getting off a long highway cruise).

Will try it in the driveway with the hood up tomorrow, see if its coming from up high or down low.

- LTDzak

[Ed_Strong]

Have you checked for a loose baffle inside the intake plenum? It's a common issue with this poorly designed intake system and it sounds just like a knocking engine!

[pitteach]

Just a shot in the dark here, but my 2000 once made a loud knock under load that turned out to be the imrc controls had fallen off. Simple replacement of bushings did the trick. I haven't heard much about the Winnys having internal engine issues, so I would rule out the simple stuff first. The trannys are a different story though-- I just had mine replaced last week at 107k.