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!

[volvospeed70]

Yeah mine is a bit rough at idle but it's been this way for about 200k miles. It just seems to be the inherent issue of it being a 5 cylinder in a fwd platform. It's easier to keep vibrations down in a rwd configuration.

My mom has a 2012 VW jetta with a 2.5 liter 5 cylinder and it idles just about the same as mine so i'm just going to chalk it up as normal and will just keep a eye on my mounts.

[vtl]

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

Double that. Replaced all 5 a while ago on V70, supersmooth and superquiet since that.

[KYANGC130]

My top mount went bad so I replaced it with the newer version of the top mount with the cross shaped rubber center piece. I didn't like it at all, the space between the rubber and the aluminum allowed too much rotation in the engine and although the vibration wasn't bad, I'd get a thunk when accelerating or decelerating the engine.

I didn't buy the expensive polyurethane bushings due to the complaints of increased vibration.

I had a tube of black silicone sealant in the garage so I filled in the center of the old one. There is no more engine rotation but it seems to be flexible enough to dampen most vibrations. Might be worth a shot if you have an old upper mount laying around. Still seems fine after about 4K miles.

6582

6583

[sanfelice]

Funny! I was going to start a thread about vibration, too.

While replacing the O2 sensor the other week, I removed the strut bar and replaced it. Well, I noticed the attachment at the rear of the upper engine mount has a certain amount of adjustment. Apparently, I had moved it too far in the opposite direction and the vibration was HORRIBLE. Almost like the tranny was going to come loose at every stop/start.

So, I removed the strut bar again and moved the mount to the exact opposite end and it has seemed to calm most things down. However, it is still worse than prior to my working on the O2 sensor. So, now I will replace the upper engine mount, which I notice has play built in to it unless it has shrunk considerably from new.

Also, should I replace that additional attachment bushing to the upper mount? That is an odd design if it has built in adjustment, I imagine the designers knew that some adjustment would be needed over time.

After that, I will try JRL's suggestion of replacing the remaining mounts (I did not realize there were four additional mounts, I''ll have to look at the diagram.

[Willy]

My engine is super-quiet: '04 XC 70. No issues there at all!
This is exactly how my 2004 feels like!
Willy

[2002V70XC]

I did a test yesterday and found that there was more vibration on the right hand side (timing belt's side). What I did was jack up the front of the car so both front wheels were above the ground and then I put the car into D so the wheel moved slowly. Then I have a feel at the wheel by touching the tyres and compared the vibration level by feel. There was much more vibration on the right side than the left side. Same feeling when you hold the steering wheel tight to feel the engine!
I think its because the design of the strut bar that has the upper engine mount on the side (instead of middle) of the engine.
I think it would always gives more vibration to the timing belt's side because the upper engine mount is much closer to the strut brace/strut tower on the left. Another point that leads me to this conclusion is that my strut bar get really hot after driving and the right hand side of the bar got much hotter than the left side.
US drivers would have less vibration than AU drivers based on my "not too solid" theory.

[vtl]

Replace all engine mounts, if you want it to be quiet (for a few years). Front and rear are made weak by design for safety reasons, they sag a lot and do not damper vibration as good as new ones.

[Astro14]

Replace all engine mounts, if you want it to be quiet (for a few years). Front and rear are made weak by design for safety reasons, they sag a lot and do not damper vibration as good as new ones.

Yep. Put 60 - 80 K miles on them, and even though they appear fine, they let vibration through. Replace them all (as I just did in the T5) and the engine will be very smooth at idle.

[pqmagic70]

My engine developed a definite roughness or harshness in vibration most notable at idle while simultaneously having the PCV system fail to the point of blowing out the cam seals. Unfortunately I just did not have time to work on the PCV system until complete failure. I was able to successfully replace the PCV system without doing any permanent damage to the engine. After the PCV repair the roughness continued. I also cleaned the ETM, replaced the mass air sensor, replaced the fuel injectors with ASNU parts, replaced the plugs and wire. Some of these parts were replaced simply due to mileage (250,000 miles) and the engine was running exceptionally well but was still rough (especially at idle). Long story short replaced front, back and side engine mounts and the vibrations disappeared. While not the smoothest motor ever designed it still runs remarkably well at 250,000 miles and can still achieve 30 mpg on the highway. While certain Volvo quirks are frustrating to deal with I can't complain about the stout I5.