engine mount

[JungloSonic]

My sonic 1.8L has a vibration and related noise that you can feel/hear in the cabin especially when at stop lights. When you press down on the engine(valve cover) the vibration goes away. Does this sound like an engine mount problem. On a side note , my valve cover has a slight oil leak.

 

[ozonetrooper]

I would start with trying to tighten the valve cover bolts.

 

[TurtleOverlord]

Probably more like the ignition coil cover that says ecotec. just pull it off and I bet the sound goes away.

 

[JungloSonic]

I don't think it is just ecotec ignition coil cover as I feel the vibrations in the cabin. You are right that the cover sometimes makes vibration sound but I don't think this is it.

I am afraid of tightening the valve cover bolts as they are to be at 71 inch pounds but mine are around 78 inch pounds and I am afraid they might get stripped. Maybe I should put in new valve cover gasket as it has some mild oil leaks.

 

[Gigachad]

I don't think it is just ecotec ignition coil cover as I feel the vibrations in the cabin. You are right that the cover sometimes makes vibration sound but I don't think this is it.

I am afraid of tightening the valve cover bolts as they are to be at 71 inch pounds but mine are around 78 inch pounds and I am afraid they might get stripped. Maybe I should put in new valve cover gasket as it has some mild oil leaks.

yeah don't tighten down the valve cover bolts further, the only solution for the oil leak would be to replace the gasket. It's not too hard of a job and the gasket is relatively inexpensive.

As for the vibrations, you could remove the coil cover to test it out, but if it's vibrating the cabin more than likely it's your mounts. I had the same issue for a while and replaced the passenger side engine mount and both transmission mounts and it made a world of a difference sound and comfortability wise, it felt like a new car for a little bit lol. It was about a 45 min job with a socket set and car jack. I can give you part numbers for the engine/transmission mounts and can dig up the diy video I used for reference.

on the valve cover gasket leak note, I would check out how much oil has leaked into the spark plug valleys, as when the rubber gasket becomes hard and brittle oil can leak into there.

 

[JungloSonic]

I have already got a new gasket for the valve cover..Just need to install.
Also, I have ordered the engine mount for Passenger side and is expected soon.
There is no oil in spark plug valleys..but I see some oil in the screw well at the front side of the valve cover..
If you have a good video and you are able to locate without too much trouble, I would appreciate.

Thanks.

 

[Gigachad]

try to find out if you have the 6t30 or 6t40 transmission as the bolt mounting pattern is different for the upper transmission mount.

 

[JungloSonic]

Thanks..I hope the mounting bolt fits OK. The one I have ordered is like the one that is on the car (the non Sport version)

 

[JungloSonic]

At what milage did you have to change the mounts. Mine has 70,000 Km

 

[SkyDog]

I just replaced engine mounts at 124,000 miles (200,000 kilometers), but they were waaaay overdue. The car's much smoother with new ones. I used OEM GM mounts, not trusting the quality or longevity of aftermarket ones.

As for the oil leak... At the very least, replace the valve cover gasket and spark plug tube seals if you've got a valve cover leak. But I'd be tempted to replace the cover itself if you're taking things apart anyway. The PCV valve is built into the valve cover on these engines, and they're likely to go bad eventually as you rack up miles. If you replace it, you'll hopefully get another problem-free 70,000 km.

 

[JungloSonic]

I agree, I should have ordered the whole cover but since I have already received the gasket including spark plug tube seals.that is what I will replace for now. However, I had read that the PVC valve problem is usually on the 1.4L turbo and not on the 1.8 so hopefully it doesn't give a problem in the near future.

when the engine mount needed replacement, did you feel vibrations when accelerating or driving or just when stopped..mine only does it when idling but smoothens out as soon as RPM starts to increase.

 

[SkyDog]

PCV valves can go bad on the 1.8, too. Mine did. Heck, pretty much any car’s PCV valve can get gummed up. It’s just a bummer that the PCV valve is built into our valve covers so it’s not quite as easy or cheap to replace.

As for vibration from worn engine & transmission mounts… It’s something that kind of sneaks up on you, with engine vibration in general getting gradually worse over time. When the mounts are really worn, though, you may notice engine movement and shaking when you start the car, or when you engage or disengage the clutch if you have a manual transmission. It kinda feels like the engine is suspended by Jell-O and you can feel it wiggle and squirm when torque changes suddenly.