Engine Vibration Poll

[Volvoholic]

My XC seems to give me a lot of vibrations from the engine. Mostly at idle and putting it in a gear. It's an '07 and just had its 75K service done at the dealer two weeks ago or so. Whenever I take it in, I make sure to have some 1 on 1 time with the tech while it's on the lift to go over the entire car and get some hands on time so I know what it looks like as it ages and what may need to be replaced soon. I'm mainly concerned with my engine and transmission mounts these days but the tech said the car is mechanically perfect. Told me my OCD about it keeps it one of the cleanest Volvos that comes into the service department when it needs to (who knows if that's actually true or not).

Anyway, it just vibrates a lot. Like...a lot. Seems to be vibrating more since the service but everything is filled right on spec. This is just some knowledge for me to see who with the 2.5L I5-T engine gets vibrations that may be excessive.

Thanks for the votes!

[StuntmanMike]

I voted a bit harsh, although I wouldn't even go that far. It's just noticeable through the steering wheel, and I don't really care for it. Dealer told me all the mounts look good, but I think I'm going to start replacing them this summer anyway. I've noticed this in 4cyl cars, so maybe it's just an inherent thing with small engines, I don't know. Every other vehicle I've owned has been a 6 or 8 cylinder.

[Volvoholic]

You bring up a good point that I should really make in this thread. Because of the nature of a 5-cylinder engine having 5 cylinders, it is more prone to excessive vibrations. This is all centered around the crankshaft. In a 5-cylinder engine, you have 3 pistons pushing down while 2 are being pushed up which tends to create a convex or concave shape on the crankshaft depending on the position and load of the greater number of pistons. In return, you wind up feeling more of the vibrations caused by the structural load on the crankshaft as the RPMs rise as compared to a 4, 6, or 8 cylinder engine that can constantly distribute a more even load along the crankshaft, creating a smoother engine experience.

The other part of this is that the larger displacement engine you get, the more robust the mounts need to be to hold the engine in place under power. If we put a V8 engine mount in a 4-cylinder car, you would feel less crankshaft vibrations but you would feel more of the torque coming from the driveshaft as the engine would torque the vehicle chassis rather than be dampened by the engine mount. This is a good reason as to why you should get a torque dampener installed as you upgrade to stiffer engine mounts. Smaller displacement engines are also more inherent to vibrations but I mean *small* displacement like 1.9L or less. I'm not including 2.0L because all the 2.0's I've driven have been exceptional. Like a 5.0L V8, exceptional.

There are many other reasons as to why you would feel more or less engine vibrations in an engine but I'm not going to get into that.

This time, wee can chalk it up to the nature of an engine with an odd number of cylinders. I was just curious as to what others experience because sometimes mine feels like it's getting bogged down and about to stall. It can be compared to how rough my friend's I-4 '93 Chevy Cavalier feels which is extremely excessive...like a massaging seat. I picked up fuel system cleaner today so when I get gas we'll see how that helps out over a couple weeks.

I do prefer a 6 or 8 cylinder engine to a 2, 3, 4, 5, or anything like that. I have yet to drive a V10 or V12 (or I-7). Though I have an overwhelming feeling a V12 is going to be excessive whereas a V10 may be my personal favorite. I'll find out someday.

[JRL]

Start with ALL the motor mounts.
You can see the top mount but the lower front and rears start to be bad at these miles
May not "look" bad but they may be

[XCNiska]

My engine is super-quiet: '04 XC 70. No issues there at all!

[sjonnie]

Compared to the super smooth i6 running the wife's XC90, yeah, the i5 is a bit harsh.

[Antherzoll]

I'd like to share this experience. While checking out a few things under the hood a thought came into my head as to why my idle had become slightly harsh. I figured that the top motor mount was resting against either the front or rear of the mount and was transmitting vibration this through the strut bar. What I did was put the car on level ground, threw it in neutral, and R&R the 18mm bolt that connects the mount to the strut bar. Vibration is much less now.

[codyfdurst]

I think mine is in the normal range. Tried my friend and it was like a tractor then I appreciated what I have. LOL

[billr99]

I've got solid mounts for the upper strut bar and a poly small bush in the lower tranny mount. Add in new main engine mounts and my engine has a bit of transmitted vibration at idle but not all that bad once off idle. Worse when it is below 0C and the rubber mounts stiffen up.

Cheers,

Bill

[2002V70XC]

I've got IPD upper poly mount and IPD strut bar mount conversion + new Hutchinson trans mount + new FEBI front rear mount and I found the steering wheel to be having abit of vibration and abit rough on "not so good" roads. I'm wondering if converting to square rubber but keep IPD solid bar conversion would give my steering a smooth feel. Its giving me the "not so comfortable" feeling holding the steering wheel!