Engine mount, right driver side as suspected.

SlickGT1 · #1 02-12-2012, 12:10 AM

Went by my friends shop to help me diagnose if my mounts are dead. So it turns out my pussy footing the throttle while in drive and on brakes is not the way one should test.

So he looks at me and tells me to get it to about 2k rpm, quick jab throttle to load it up, followed by another jab. I'm like ok, stand to the side. I nail the gas and my driver side mount is shot. The engine pops out a good 3" on driver side with a loud thud. In reverse, solid. Yay, mount gave up totally.

He tells me to replace just the one mount, what do you guys think?

I was thinking both engine, and trans mount at same time.

If someone will try this diagnosis, be smart and stand to the side of the car while someone puts car in drive, holds brake, and punches it. I'm not responsible for your stupidity.

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Secret Ag · #2 02-12-2012, 01:10 AM

I have the exact same problem right now as well. You can get away with just replacing the broken mount but depending on how long it has been broken it has put a bit of extra strain on the other mount. I am planning on replacing all 3 so I dont have to screw with it anytime in the future. Plus it is a couple more parts on the journey to replacing everything on the car.

TriX5 · #3 02-12-2012, 09:09 AM

Just to give us a flavor of what happened... What symptoms led you to believe it was broken in the first place? What is the mileage on the car?

BTW. the rear mount for the trans is quite distinct from the engine mounts I wonder why you want to replace at the same time?

Ghost-Flame · #4 02-12-2012, 10:21 AM

Yup, sounds like a broken motor mount. Never had one in the X but had sveral in Fords and VW's I've owned and what you describe is exactly how those that failed on me acted. The quick jolt of rpm torques the engine away from the broken mount. I would replace both because of stress on the non broken mount.

This can be a DIY I believe you can use a jack to lift the engine to get at the motor mounts, but, I'm not sure. Also an engine lift will work if you have access to one.

SlickGT1 · #5 02-12-2012, 01:06 PM

Quote:

Originally Posted by Secret Ag

I have the exact same problem right now as well. You can get away with just replacing the broken mount but depending on how long it has been broken it has put a bit of extra strain on the other mount. I am planning on replacing all 3 so I dont have to screw with it anytime in the future. Plus it is a couple more parts on the journey to replacing everything on the car.

Yea I'm thinking it was bad for a while, ever since I got it, just now it's fully ripped. All three for me too, don't want to have to diagnose a mount in the future.

SlickGT1 · #6 02-12-2012, 01:27 PM

TriX5
2006, 4.8is, 78K miles.

Yea so I was 95 percent sure that the mounts were shot they day I got the car. Not completely shot, but in need of replacement. My unfamiliarity with the car led me on a chase for other issues before tackling the mount. About a week ago, I was 99 percent sure the mounts are now completely done. I feel like I should have followed my instinct and changed them, but I was hesitant since there might have been other issues at play. There weren't. I did preventative maintenance anyway, but nothing helped this specific problem. New plugs, cleaned maf, cleaned TB, new fuel filter, new air filter, oil and filter. Nothing helped the above.

So since day one, the test that has never failed me is the vibration, more vibration in drive, and vibration in reverse. Vibration in P and N much less but there. If you turn the AC on, the vibration in every gear becomes 70 percent less. This is exactly the same diagnosis I have had with every broken mount I ever dealt with. The AC on test is what always settles it for me, especially since there are no codes or anything. To re-enforce my theory, I started paying attention to delay of the line. You press the go pedal, but there is just that slight delay before the car moves. Shifts seem like they rock the boat ever so slightly.

Read last reply. I have a theory on some stuff.

SlickGT1 · #7 02-13-2012, 11:55 AM

Quote:

Originally Posted by Ghost-Flame

Yup, sounds like a broken motor mount. Never had one in the X but had sveral in Fords and VW's I've owned and what you describe is exactly how those that failed on me acted. The quick jolt of rpm torques the engine away from the broken mount. I would replace both because of stress on the non broken mount.

This can be a DIY I believe you can use a jack to lift the engine to get at the motor mounts, but, I'm not sure. Also an engine lift will work if you have access to one.

Had the same thing on my last Lexus. I'm hard with the go pedal. So once the vibration started, turning on the AC makes the vibration much less. At that point, I start checking mounts. I bought my last car with 74k miles. Replaced mounts at 84k, and then again at 130k.

Yea I am pretty sure I am going to do this myself. My bud has a shop, so I just need to get in there when the lifts are free, and he will even help me with it. As a matter of fact, he actually has 1 new mount, a used amp, and pass window regulator that he is giving me. Yay.

Doing all 3 mounts for sure. Don't want to be diagnosing the next vibration and thinking, maybe it's the other mounts.

SlickGT1 · #8 02-13-2012, 12:01 PM

So I have a theory. You know how our Torque Converters have anti vibration damping, well how likely is is that our failing mounts are making the TC work harder, or out of spec when the engine mounts are shot. I am thinking that with destroyed mounts, a lot of symptoms feel like the trans is going. I will deff know for sure once new mounts are in.

I suggest everyone go and check their mounts. Why? Well because I doubt there are many owners out there that actually floor their car as often as I do. When driving normal with the family, the mounts "seem tight", everything works still. I am shocked at how planted everything is with a torn mount. We are talking about a completely torn mount here, and the car barely shows you symptoms. I mean, if you are used to driving with AC on, you might not even notice it. It really makes that big of a difference.

And yes, I checked my idle rpm with the GT1. I didn't raise it, because like I said, I was 95 percent sure the mounts were bad from day one.

SlickGT1 · #9 03-03-2012, 04:16 PM

Update. Fixed. Just came back from the Indy. Great props to these guys for a nice clean job. If anyone is looking for a good shop with good prices in Brooklyn ny, hit up Trio Auto.

So they did the following.
1. Replaced both engine mounts. Driver side was a bitch by the way, very little wiggle room.
2. Removed trans brace to inspect rear mount, good condition.
3. Removed belts to check all pulleys, and tensioners, tensioner bad
4. Alternator seems to be making that supercharger noise.
5. Cleaned entire engine to find source of oil leak.

$140 for 3 hours of work. $160 with tip. Not bad at all. But I know these guys for 14 years.

So holy shit. Car is smooth as silk again. No vibrations, no throttle delay.

That lurch. Yea it's practically non-existent now. I guess this, and trans pan 2x drop and fill, 1x filter, great stuff. Very happy those nasty ass vibrations are gone.

Drivers mount was destroyed. Oil leaked out of it. Pass side mount looked decent, mechs told me to keep it just in case. All in all good day.

Going back in 2 weeks to find leak. I hope.

SlickGT1 · #10 03-03-2012, 04:22 PM

By the way 4.8is here. No way can driver side mount be DIY unless you have a lift, and a good selection of tools to fit the tight space. Even with that, the subframe had to drop about 6 inches, while engine lifted to get mount out. Note, no other parts removed, not even wheels. Pass side is comparatively easy, and took like 30 min.

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