I've recently noticed a strange noise on my 78 308. The sound comes and goes, is not speed dependent but does not present itself at idle. It sounds almost like a bearing but the intermittent nature makes me think it's not. It also seems to be the worst when I am braking or when I drive over a large bump at speed. It seems to be coming from down around the alternator. I've had the wheel well out and looked around but there is nothing that could be rubbing unless there is SIGNIFICANT movement of the whole engine. Talking with several folks, one touched on something that had been crossing my mind....motor mounts. If one of them were bad I suppose under braking and over bumps the engine could move and create the noise (although I'm still not sure what would be rubbing to make the noise). I've searched and found several threads about motor mounts and even the one where someone had found suitable poly replacements, but I could not find a thread with any kind of explanation about how to check to see if they are bad. Do you just have to pull them and take them apart to see? I know on older muscle cars with an auto trans you could kind of power brake it with the hood up and see if the mounts were loose. Kinda hard to do that with this car though!! Also if I'm going to pull them what is the best way to get the engine up to allow clearance to get them out? Thanks in advance for the help!! John
I had one like that. Turned out to be the exhaust heat shroud vibrating. Annoyed the crap out of me for a while! (SOrry, I have no answer on the engine mounts....but I suspected mine as well. I used a big ass pry bar to wiggle the engine from under the car on the lift and decided that they weren't the issue).
I am in the process of replacing all the mounts on my 78 308. One of the old ones I cut open and unless yours were changed I am pretty sure that they are similar to mine. Inside is a spring that was completely rusted out, I suppose some water eventually gets in there and everything turns more or less into a block of rust. I am quite surprised that engine mounts don't cause more problems and are not more often referred to on this forum. Helmut
