Violent idling with new engine mounts

[Bad_Mechanic]

Hello, I have a 2000 Mazda 626 LX, 2.0L 4 cyl, automatic, 145k miles, that is idling very badly. This car has a total of 5 mounts: rights side, left side above transmission, one below the transmission, one up against the firewall, and one on the radiator support. I had everyone except the rear one 2 months ago. Idle was fine but I was told (and they were right) that the rear mount was broken. So I had it replaced. The part number ordered was DEA A6405. Well after the rear mount was installed 2 days ago the car has been idling very violently. You can feel it in the seat and steering wheel. Also, you can see the whole front bumper and the right side front quarter panel vibrate. With the hood open the engine is can be seen vibrating a lot(!!).

I took it to another mechanic today and he observed a few things as did I.
(1) The small transmission mount that goes underneath is lopsided, as its’ profile looks something like this __ (imagine a line parallel to the bottom one).
(2) The through bolt of the front mount is no perfectly centered, as the weight of the engine is making the bushing touch the top back (towards the rear of the car) wall of the mount.
(3) The rear mount that was installed does not fit within the bracket lateral-wise. I l_1I The I’s are the bracket ends and the 1’s are the ends of the mount. All the holes and bolts line up though, there’s just a space at the right end.
(4) Right-front quarter panel vibrates much more than the front-left does.
(5) When the mechanic loosened the front mount, the bolt changed position, so he tightened the nuts and bolts that held the mount in a way that centered the bushing in the mount. It seems to have returned to its original position though.

What is wrong? What should I do?

I know I’m not suppose to guide the reader to a solution but I just felt I needed to illustrate what has been done to the car.

Topic

[David]

Take it back to the first bloke who fitted your rear mount and say fix it……

[Daniel]

Take it back. The guy should have realized that something was wrong as soon as he finished the job.

[Bad_Mechanic]

I did, he said that the rear engine mount is DOA and another mechanic says just remove the front mount altogether. What could i do as far as DIY? What is the correct general procedure for installing and tightening mount bolts?

[Daniel]

I would make them do it but, typically all you do is:
-Put a jack under the oil pan. Make sure you put a piece of wood between the jack and the oil pan to reduce the risk of damage.
-Jack the engine up just enough to unload the mounts.
-Unbolt the old mount, install the new one, you don’t have to torque the hell outta the bolts.

Try going to autozone.com They should have step by step instructions.

[Bad_Mechanic]

I ask because if only 1 mount was replaced, shouldn’t all the mounts be loosened and retorqued? I’m thinking that if a new mount is put in the position and strain put on all the other mounts changes. Am I wrong?

[Daniel]

The rubber mounts are flexible rubber, so no re-adjustment is needed. But this is moot, since the weight of the engine is supported by a jack while the mount is being replaced.

[Bad_Mechanic]

When the rear mount was put in.the engine was not supported very much. It was only supported to line up the throughbolt.

[Daniel]

Alignment is the main purpose of the engine jack. It’s starting to sound like the engine/trans mount was just a secondary symptom. Do you have a check engine light on?

[Bad_Mechanic]

Not that I know, I should check though. Never have and the car was baught used. I do have a loose intake hose clamp at the throttle but the hose is on as normal at each end.

[Daniel]

If you have a “loose clamp” then it is not “on as normal.” You need to tighten that hose. Your problem is most likely “un-monitored air (aka a vacuum leak).”

[Bad_Mechanic]

It’s okay, I thought the clamp was still loose but my mom took it to a mechanic to look at it and it seems he tightened it. A few new developments though: i had the OBD reader on as as I suspected the check engine bulb isn’t there to light up the indicator because 3 codes were retrieved
P0400
P0443
P0455
Also, i was driving the car today and it jerkes hard gong into secend gear, it’s automatic, as it always has but this time after it went into second gear it’s as if the car didn’t want to accelerate. I would give it gas and the reving engine would sound loud and mugfled as if it was being overworked. And when I let off the gas it jerked hard going back a gear, it never does that. When I got to a stop light and then went to accelerate it was back to normal, only jerk was from gear 1 to 2. Related?

[Cody Beaudet]

For what it’s worth, I believe all of those codes affect the EVAP system, and thus shouldn’t directly correlate with any of the symptoms you have described. As stated before, this seems to be indicative of a larger problem. I would suggest pulling a plug to look at the running condition of the engine, listening around for vacuum leaks, as well as checking your transmission fluid. That’s usually a decent place to start for a DIY’er. The fact that you’re not retrieving any codes for the plethora of sensors that contribute to a healthy engine doesn’t rule them out as culprits, either. If possible, take it back to your mechanic and have him connect it to a scanner to have a look at real-time data. Without more info, it’s really difficult to track down problems unless you’re very experienced and there in person, or just reeeeaally lucky.

🙂

P.S. People have had luck fixing those codes by replacing their gas cap, purge solenoid or evap canister. Seems like you have more serious problems to concern yourself with though! 😀

[college man]

P0400-EGR flow failure here some links to help.

http://www.justanswer.com/mazda/44xo0-1999-626-2-5-v6-p0400-egr-flow-failure-common.html

P0443-evap purge solenoid valve.

http://www.justanswer.com/mazda/4dk5s-mazda-626-p0443-fix.html

P)455-Evap system excessive leak

http://www.justanswer.com/mazda/6qft1-mazda-6926-98-mazda-626-throwing-p0455.html

[Bad_Mechanic]

[quote=”college man” post=66774]P0400-EGR flow failure here some links to help.

http://www.justanswer.com/mazda/44xo0-1999-626-2-5-v6-p0400-egr-flow-failure-common.html

P0443-evap purge solenoid valve.

http://www.justanswer.com/mazda/4dk5s-mazda-626-p0443-fix.html

P)455-Evap system excessive leak

http://www.justanswer.com/mazda/6qft1-mazda-6926-98-mazda-626-throwing-p0455.html%5B/quote%5D

Thatnls for the videos, will deffinitely pick up a dictionary when i get to that 0443. Ha!

I went to the junk yard today and noticed something: the bracked that sandwiched the rubber insert of the mount touches both ends of the mount, the new mount I had installed does not do this. Any new thoughts?
I managed to take the mount off on my own. Time consumming but not too bad, deffinitely gotta buy ratcheting wrenches though.

[Daniel]

You should not be fooling with that mount. The job that the shop did should be under warranty. You messing with it, instead of having them repair it, means you voided the warranty.
You should bring the vehicle to a reputable shop for further diagnosis. You are not going to have the tools necessary to figure out the evap system problem. This will prevent you buying and replacing parts that are not contributing to the problem.

[Author]

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