Join Date: Jul 2013
Model: Mercury Sable
Engine: 3.0L 24v Duratec V6
Rep Power: 14
Bad Belt Tensioner
Just wanted to give you guys a tip out there in case my experience matches anyone elses or maybe can help you out...
A few months back I replaced my water pump and a couple other things. The drive belt is pretty new, but while I had the belt off the engine I figured I should replace the tensioner too, as it was original, and people say it is a wear item. I have a parts car that was mine and got totalled, and on my parts car I had a Gates tensioner with less than 10,000 miles on it, so I figured why not just pull that one off and pop it on my car.
After everything was all back together, it seemed like the engine ran louder and a bit rougher than before. Also, I could tell something was definitely different because in the past, whenever I started the car and the idle was high, I would often give it a little gas and let go, and the idle would quickly drop down to normal. After this job, it would not drop down quickly, but much more gradually.
I suspected the tensioner, but didn't really know for sure, as the car wasn't exhibiting signs that indicated bad tensioner, at least based on my search results for bad tensioner. It's just that the engine sounded a bit loud or rough, and if not for my prior familiarity with the car, or if someone is a bit of an expert with how engines should run (which I'm not), it's very possible that nothing would seem so "off" about it.
Anyway, today I FINALLY got around to putting a new Motorcraft tensioner on the car. Well, good news. Back running the way she used to. I'm guessing that maybe the tension from the Gates tensioner was too tight? Now regardless of that, I don't know if the problem was because that Gates part failed prematurely, was poorer quality, or perhaps even whether it somehow got damaged when that car was totalled (?) but the Motorcraft part in this case did the trick. Not sure if anyone else might have a similar situation to mine where there is nothing else clear to suspect, but I'm happy that I solved it and it didn't just turn into throwing parts at a problem.