curls

So my recent problems with the DC header flex continually separating have led me to thinking about other contributing factors in why this is happening. Some exhaust gurus have said it could be because of excess engine movement (rocking) that is pulling the flex pipe apart. Seems logical.

Then I started thinking... "What else is my car telling me?". I immediately remembered my brother asking one time "Why the hell does your car shake and rattle when you are just starting out from a dead stop in 1st gear?".

I have a 6MT and have been driving a manual transmission for over 10 years. I know how to drive it, and well. But I've seemingly always had this problem where the entire front of the car shakes/vibrates when just getting off of the clutch pedal and applying the gas. The contents of my change tray rattle, my glovebox rattles, and everything is silent again the moment I'm fully off the clutch and driving.

Maybe, just maybe, it's a bad engine mount? If the engine was rocking (during the acceleration w/ clutch interaction), it would explain the pretty intense vibration/shaking, as well as its excess movement continually ripping the header flex pipe apart. I do have an Ingalls "Stiffy" engine torque damper installed -- maybe it's not a replacement for a busted/worn engine mount though!?

Anyhow, enough rambling on. How can I inspect the engine mounts to see if one or more is 'bad' and in need of replacement? Also, if I find a 'bad' one, can I replace it without the use of a cherry-picker (engine hoist)? I have a very strong, 22" lift floor jack, jack stands, and the OEM jack at my disposal...

Thanks!

curls

I'm bumping my own 1-year-old post as the new header (DC copy: Japspeed, $85!) is beginning to suffer the same flex-pipe separation. I guess the engine torque damper (ETD) can't handle whatever engine torque I'm throwing at it.
This leads me to think that one or more mounts are degraded. How can I check these? My mechanic buddy says he just goes by the eyeball gauge (how much the engine rocks) but there's gotta be a way to tell which mount is bad, no?

Any help appreciated!

CarbonGray Earl

I don;t know how to check it, but I can tell you that for the modest torque our engines put out, the engine mount sure do wear easily.

I had one replaced about 2 years ago at 90 thousand miles. I'm interested to see how to check it as well....I think another might be out on my car, as I'm getting some funky vibrations again.

curls

Before the one was replaced, what were your symptoms? Vibrations at take-off and also possibly an engine-rocking feeling during shifts (6MT)?

I might replace both front AND rear, if one or the other, is done... odds are the other will go soon enough anyhow.

JTso

iTrader: (2)

The front mount toward the radiator is not a standard mount and is controlled by the engine vacuum signal to "firm up" during hard acceleration. You will find the control solenoid on top of the intake manifold. If this is not working, it may cause other mounts to fail.

2k5TSX

Anyway to confirm if this is working? Can the dealer confirm?

xaznperswaesonx

If the control solenoid fails, you should get a heck engine light.

In regards to diagnosing motor mount on a manual trans. Onr way is jack the car up on tands. Use the jack and lift the engine near the location of the mount and then release the jack. Watch he way the engine react. If it looks like it moves freely and uncontrolled. Its a good indication that its bad.

The passenget side mount is easy. One is to use the jack to support the engine and remove the mount at the bracket point on the motor. Its a 17 mm bolt. Long bolt is the rear. Once bracket disconnected. Move the mount wih our hand .. if its fairly easy to move its bad. Another way is to pull the boot up and look for leak and tears as its hydraulic.

Rear mount same thing as front. Just use the jack up and release method. Think of bounce test on suspenson.

Tranny mount is easy .. just look for tears

curls

I ended up buying 4 new mounts (not sure I'll need them all but I got the 4 main ones that would deteriorate and cause rocking of the engine:
Front and Rear engine mounts.
Two of the Transmission mounts (can't remember which two off the top of my head).

I'll just replace 'em all at once and hope that fixes the problem. I need some wrenching time with the car, it's been a few months, it'll be a bit of a rekindling/bonding moment between me and the car.

I'll definitely inspect the parts that are coming off of the car and take pics if I see anything unusual. For what its worth, the engine side mount looked fine, and, it also isn't a mount that if broken would cause the engine to rock. That's what the front and rear beefy mounts are there to control.

xaznperswaesonx

tranny mount you can just look at tho. no need to diagnose. they're solid mounts.

curls

Yeah the one I could easily see "looks" fine but for $15ish I figured I'd replace it as the rubber can get tired and crack after almost 8 years on the road (early 2004 model which was on the road in March 2003!).

I still have to find an afternoon to get these installed. My garage is full of kids stuff right now so I need an hour to clean that out before I get to the real work! LOL.

curls

OK, so I FINALLY found some time to clean the garage and get some wrenching-time in. I was able to easily replace the two lower tranny mounts (top/front one was perfectly fine). Also the front engine mount was a relatively easy replacement -- just remove the upper rad hose, both rad fans and then attack the mount. The REAR engine mount was impossible though. Accessing the top bracket is easy (with the following tools: 1/2" drive universal joint, about 18"-20" of extensions, and a 1/2" drive ratchet). LOL. Once that was off, the bolt that goes horizontally into the bracket (connecting it to the engine) was IMPOSSIBLE to access. Below is a subframe crossmember and the front sway bar. Above is some lines and wires (non-movable), and behind is the firewall. I can get a ratchet on it, but there's NO way to get leverage on it, and it's on there damn tight. Another option MIGHT be to remove the 4 big mother f'n bolts holding the bracket to the block, and then removing the engine mount + bracket as one unit, but I can't see any way that would fit, even remotely fit, through the path required to remove it from the car.

Needless to say, the rear engine mount is still OEM/untouched.

Now... replacing the front mount and two of the three tranny mounts - HUGE DIFFERENCE. My Ingalls ETD now really stiffens up the engine and frankly at 12mm is WAY too stiff. The new mount(s) have made the car like-new again.
I will attempt the rear mount again at some point but not anytime soon. It's great as-is, but I know that the front mount made a huge difference and the rear should be an even bigger difference.

For anyone interested, there's two things to know about the front mount: 1. The existing mount looked perfectly fine. No tears, cracks, or apparent defects. 2. The new mount (Anchor brand from rockauto.com) did NOT have a nipple for the vacuum hose to connect to. As such, my front mount is now NOT a dual-stiffness mount but it seems fine, and no CEL either.

Cheers,
Eric

vthree

iTrader: (1)

i may look into replacing the front as well.

when I had my car dyno done a few years back at T1Racing - Tony said that he had seen a similar ETD on an s2k - and said to be careful/consider taking it out because he's seen it wear out motor mounts before.

curls

I'm pretty sure my motor mounts were worn out before the ETD was installed because I broke two flex pipes on my headers, even after the suggested mods to fix/prevent it. One solution that was suggested at that time was to install an ETD since the mounts "looked" fine. The mounts I removed still "look" fine for the most-part but they sure weren't performing like new ones.

Chad05TL

I think you are right. You will not be able to tell if they are bad or broken by appearance. You might be able to tell if one is bad after you remove it from the car and it breaks in your hand but I just replaced the front, the side and the rear mounts and they were all not cracked or broken. However, they can be stiff and not providing the shock absorption even while not being cracked or physically broken. I have not had enough time to drive me car, because I just drove straight home from the auto shop on the highway. But while I was at the shop, when I started the car to leave, it felt like it was not kicking as hard. And it idles like a new car. So I think there is going to be a noticeable difference tomorrow morning when the car is stone cold; that is when I noticed a harsh kick as the motor ignited. So tomorrow morning I will be able to tell more. And next week I will see how it drives. This evening I only drove it home on the highway and parked it. Traffic was terrible. But from what I can tell, it was worth the money. My 05 has 65k miles and I also did the timing belt and water pump, seals and belt tensioner which was leaking (if that is possible) and whatever else comes with it. They also checked my air bag light, and it is a open circuit on the left seat belt. “SRS Code 61-1 Open in Left seat belt Buckle Switch”. So that is going to the dealer for warranty. Then all I need to do is fix the Bluetooth sync problem with Schoche BFHAK and the car will be new again. Haha And hopefully last to 100k miles.

But ya, I think the motor mounts are impossible to tell if they are bad while on the car. And they may not even come apart after you remove them. I think mine were bad at 35k miles. My symptoms were, rough idle when cold only, and unusually hard hit when starting, and also a hard hit when going from 2nd to 3rd gear at a slow speed and light throttle. And sometimes I thought it was slow to respond as I went from breaking to acceleration; like in that short process. Again, tomorrow and this week I will be able to tell, more. I just got all this work done today and based on what I felt as I drove home, I think I may be really excited tomorrow as I drive it more.

Chad05TL

After a little while of driving this is what I can tell.
Cold and warm starts are smoother.
Cold idle still has some light vibrations but it is somewhat smoother. Like maybe 50% smoother but the new mounts did not eliminate all the cold rough idle.
In town stop and go driving and shifting is more responsive and less delay. Now when I press on the gas is goes instead of waiting 1/2 a second. I remember getting a delay entering the gate at my apartment. As I slowed down to let the gate open then accelerate, there was a very annoying lag from slow down to accelerate. And it doesn't seem to be there now.
The mounts were not physically broken. They looked fine. But I chose to replace them anyway. So was it worth it? Well, it depends on how much money you have. I did 3 motor mounts and probably only needed 1 or 2. But it's hard to tell when they all look fine. I spent 500-600 on parts and labor. I am satisfied but if I was going to sell the car soon, I would not replace them. Most people probably would not be able to tell a difference until you drive it a while and start wondering why it responds the way it does. Even so, like I said the mounts were not physically broken so there is no hurt in leaving the car the way it was. So, it's not like the motor is going to fall out. I think motor mounts are a bite overhyped on this website and get too much attention. Basically, my recommendation is, unless you are for sure having a problem, then it may not be worth changing them out. Just know that if you do change them out, then the difference may only be "marginal" at best. But if you see a crack in one, then yes, replace it. But if you symptoms are light, then you may only see marginal improvement because I think some of these motor mounts may get stiff over time (rubber gets harder) and so there is still something to be gained even if they are not cracked or broken. However, there a few run off a vacuum. So something is going in there too. So most likely there will be some added benefit if you experience any lag and replace them. But it won't be a huge difference.

paperboy42190

iTrader: (7)

It's not that hard to change the rear motor mount.... It's the same procedures as a TL except ours are harder because the engine blocks it even more. Should be very easy with the k24 way more space.