What exactly does this mount do compared to the other ones with the fact that it's labeled as a hydraulic mount?

I think I might know the source of my weird grindy/vibraty sounds but have to get a couple things clarified.

SPANKS.

 

The front one is a hydraulic mount as well. If it is totally bad and blown out you will see what looks like rusty water stained around the mount.

 

Not so much that. But the rear mount, if it is hydraulic, does that mean that it can settle over a period of time if it's on a slant?

This is what I'm thinking, I started up my car today and did not get the sound that I did yesterday as the RPM's were dropping, but I did when I first accelerated and a couple times accelerating from a stop. As I said before I got the same kind of sound when I accelerated hard, especially around the time I would start boosting and getting some nice torque. I pinpointed the vibration and it seems like it's coming between the front seats. ANYWAYS, I looked under my car when I got back to my apartment and noticed that the exhaust pipe right after the DP, where it fits between that metal sheet and the bottom of the car, was sitting really close, almost sitting on, that sheet of metal.

Now my theory is that my parking spot is slanted, so my car is parked on a slant all night and all day while I'm at work, when I start my car and pull onto the flat alley, the engine is leaning slightly back due to the hydraulic mount, just enough that when I take off for the first time there is some vibration between that metal plate and my exhaust, but once I start driving the engine levels out a little bit, enough not to create any exhaust vibrations. But when I get hard accelerations, there's enough torque to tilt the engine causing the vibrations. The sounds only started occurring after I put on my exhaust, so I feel like it has to do with it.

Does this sound reasonable????

 

Yes and no. It is set at a specific pressure. There is not much give in it.
Look at it like this think of it as a balloon that is really tough. It will not really settle it can move around a little but not sag and stay sagged. It would move as soon as it hit level ground.

 

Hmmmm... I wonder what would be making that noise then. It sounds like it was coming from right under the center console. That pipe was sitting really close to the metal, and I think that that had to be causing some of it. It's just weird that it's only happening noticeably with my first acceleration and and hard acceleration. My car shifts perfectly fine, so I don't think it's my tranny. It does sound like something is loose under my car, there's knocking when I go over bumps, most noticeably on rolling bumps like messed up parking lots, but I'm assuming those are the struts.

 

Check the metal cover over the steering rack sometimes it will walk up and it could be hitting the exhaust.

 

Good idea, that thing did get pretty loose as we were working with the exhaust and taking the DP in and out, I had put it back in place, but it's very possible that it could have shifted or loosened up more.

 

take if off, bend the mounts a little tighter then they need to be, and then pop it back on (might need a good fist or rubber mallet )

 

Yeah, I'm going home today to try that to see if that's what the problem is. It would be hard to believe that it something else just because it's only occurred since I put the exhaust on. I might get a piece of silicone hose and then cut it in half and put it on the exhaust right there with a clamp, see if that takes care of the vibration, and then if it does, bend the mounts. and make sure everything is tight as well.

 

make sure it is high temp hose so u dont melt the ****...

 

Yeah, tha's why I would make sure to get some silicone hose or something, something like the samco hoses. I could really get anything, doesn't have to be large. What's a good hose that takes a lot of heat that I could just get a small piece of?

 

I checked under my car today and there wasn't anything that seemed out of place to be causing this noise. It only happens when I take off from a stop, and it's not all the time. And when I'm accellerating hard right around the time I start to boost. It's a harsh vibration noise and it feels like it is coming from underneath the center console. No changes in my transmission, still shifts the same. The noise started around the same time I put on my new exhaust.

Could this maybe be resonance with my new exhuast? Maybe it is where the 3" DP is hitting the 2.5" exhaust?

Any ideas will be greatly appreciated.

Thank you.

 

Is the rear mount bad?

 

Well we replaced the one rear mount just a little while ago and the hydraulic one is completely dry. It isn't doing as much now. I don't know what it was, but I think I was more paranoid more than anything. If it persists, then I'll look further into it.

However, on a side note, after redoing my PCV system, it is now leaking oil, and it appears to be leaking oil from the top hose. We went back in there and took it out took off the hoses and put them back on, making sure to really tighten the clamps. All the clamps are tight, but it's still leaking. Could the oil trap maybe have clogged again after everything was hooked up again and all the vacuum lines were finally reattached properly, since they were left undone from the previous mechanic who did it, and oil that has been sitting in the engine made it's way into the trap all at once??? At the same time, I am getting less blow by coming out of the dip stick then I've ever had. It just seems weird that it would be leaking out of the top of the trap, I don't know, maybe it's coming from somewhere else, I don't know where else it would be, but it looks like it's coming from there.

SPANKS

 

1. I went through the same thing when I installed my exhaust. My DP is supposed to be a 3 inch but I actually think it is bigger I almost had to remove the shield on mine also the DP almost did not fit through the hole to install it. But after some bending on things I only get a rattle once in a while.

2. Are all the vacuum line clear?

 

They should be. I can check them again tomorrow probably. I don't know how they would clog, It wasn't touched since we put it in, and then we noticed it was leaking when we did the exhaust, even though it had been dry for quite some time.

 

did you wind up changing out the rear engine mount.

 

No, because it wasn't the problem.