So whenever it's stopped, regardless of whether or not it's in park or in gear, the steering wheel vibration gets increasingly worse the longer it's idling (up to a point), even though from what I can tell by ear the engine RPM doesn't increase. However, when I have my foot on the accelerator the vibration doesn't totally go away, although it is significantly dampened. But when I take my foot off the accelerator and start coasting (in gear of course) the vibration starts up again and is pretty noticable. Any ideas what it could be?


EDIT: Here's the list of the causes of the extra vibration:

1.) Misfiring engine (a small vacuum leak, a dying fuel pump, and a plugged fuel injector)
2.) Decaying engine and transmission mounts.
3.) A wheel bearing going bad.
4.) Decaying rubber on the air compressor mount.
5.) Cold weather (there's almost no vibration after it's been running for a long while).
6.) Bad lower control arm and sway bar bushings

 

yr and model ?

 

1988 Delta 88

 

Has anything in the engine, flexplate, or converter been changedor disassembled?

 

check your driver side motor mount, probably crushed or broken and feeling it through the wheel.

 

X2. I bet the steering rod is resting against the motor in some fashion.

 

I had the radiator replaced and the AC converted to R-134, but it was doing this to some degree before that.



Thanks, I'll get that looked at.

 

Pretty much could be anything. Sticky injector, bad plug, bad coil, etc, etc.

Start with the old standby of alternately disconnecting plug wires to see which one does NOT result in an RPM drop. Obviously, take care not to get shocked. On your car you can probably pull the wires at the coil pack, since reaching the back three plugs with the engine running will be difficult.

When you find a cylinder that does not cause the RPM do drop, start your troubleshooting. Have you ever had the injectors cleaned? When was the last time the plugs were changed? Plug wires? Coils?

 

I'm not very mechanically oriented, I wouldn't know where to start with any of that. I took it into the mechanic today (AC compressor blew out and needs to be replaced) and mentioned the problem. Hopefully the mystery will be uncovered soon. I asked here because I was curious what it could be and to learn more about how things work.

As for that stuff, this car is fairly new to me, I bought it a couple of months ago. It was tuned up not too long ago, although I'm forgetting exactly how long ago. Despite some of the issues it had it was in fairly good shape.

 

So an update, my mechanic checked the engine mounts and found them still in great shape, so that isn't the problem. Since that's not the issue, could the potential problem be serious? If not I'm tempted to leave it alone for a short time.

 

What did your mechanic think it was? He was there to listen and look at it. Its hard for us blind and deaf types to diagnose from afar......Tedd

 

if it's a misfire and your mec hasn't caught that by now, I'd suggest finding another mechanic. You can easily start yourself with what JoeP said above.

 

He wasn't sure, at the time I asked him to check the most obvious potential problem as part of some other work he was doing, so it was done for free. For a more detailed inspection I would have pay to hunt it down. I will of course do that, it's a question of when. For financial reasons I'd much rather it be later rather than sooner if I can get away with it. But if the problem could be something serious I would get it looked it right away.


We don't know that it is a misfire. Wouldn't there be other symptoms if that was the case? Unfortunately when it comes to such things I have a tendency to turn something simple into a huge project, especially since I've never worked on an engine before in my life.

 

We don't know that it is a misfire. Wouldn't there be other symptoms if that was the case? Unfortunately when it comes to such things I have a tendency to turn something simple into a huge project, especially since I've never worked on an engine before in my life.[/QUOTE]

It may only present itself at low RPM. This is something the mechanic should of done first. here is the process in action .
it's a 4 banger but the same concept applies. Look for change in RPM and don't shock yourself!!!!

 

Well today on the freeway it started droning loudly and vibrating in the floor when I coasted between 50 and 55, something it never did before at that speed. Because of that seeming progressive nature of the problem I decided to take it in and have it looked at tomorrow. When I asked about it my mechanic said he doesn't charge for diagnosis of a problem if any needed repairs are done at his place. He's done well at diagnosing other issues before and if something went wrong with the repair work he's honored his warranties with no hassles.

 

Did you get a diagnosis yet?

 

Just got it back, the problem was mostly a misfire and cleaning out the MAF sensor, the intake and the throttle plate thing (I forget the name of it). That definitely helped it a lot, it still vibrates on idle, especially through the steering wheel, but not as much as before (the drivers side window doesn't rattle anymore). Getting it up to speed past 30 it doesn't howl anymore, and even at lower speeds it sounds very very different from before. So the engine was a big part of that problem. I consider it mostly resolved for now, I'll revisit it later.

 

As it turns out I couldn't leave it alone as long as I had hoped. It ran ok a day after that cleaning was done, but it actually made it more random. I drive down the road, then at a stop light it's pretty much gone. Go for another couple of stoplights and it's back.

So I took it in again. This time they tested the fuel injectors, coil packs, spark plugs, and as I recall some other stuff. Nothing, it was all working fine. Funny thing is, it isn't just one cylinder that's misfiring, it's all of them (though never all at once). Although sometimes none of them misfire. It occurred to me the issue might be bad gas, since I needed my car back we decided to try some gas drier additive, for a day seemed to work. Now it isn't again, although it could take more time to work its way through. Then again given the totally random nature that could have just been a fluke. Or maybe I needed to run the tank down more before refilling it. We'll see.

In the meantime I'm wondering what else it could be. Bad sensor maybe?

 

Wow. That stinks. Possibly the ECM going bad? Even vacuum hoses can cause craziness like what you are describing. Hope you can find this gremlin soon...

 

Yeah, we'll know after I run through the next tank full whether or not my bad gas theory is accurate. I'm hoping to sneak in a road trip or two to accelerate the process. But just in case I'm wrong about that, I'm making a list of other stuff it could be that as far as I can recall weren't checked yet. I'll add your ideas to the list, thanks. There's only so many things it can be and several possible culprits have already been eliminated, we'll just keep testing theories until we land on the right one. I'll continue updating this thread as things progress.

 

When all else fails a compression check wiil tell you a weak cylinder.

 

Well as it turns out this vibration and droning isn't one problem as was first thought but actually several different problems that have combined together to ruin the ride. So the cylinder misfire problem turned out to be a combination of a small vacuum leak and a dying fuel pump, got that fixed up and the engine runs great again.

Now the droning wasn't the engine at all, the front drivers side wheel bearing was going bad, currently I'm awaiting it's replacement.

However, it is still vibrating on idle. I ran an experiment this morning before taking it in, it vibrated in park, reverse and drive. When going around 5 mph like in a parking lot, there's no vibration at all. Granted going faster tends to start vibrating, but that's probably the wheel bearing. It also doesn't vibrate when I put it in neutral. I suspect it might be the transmission mounts starting to go.

This turned out to have a few more teething problems than I had hoped, but I think it's worth it. It's also developed an odd creaking problem, I'm not sure what to think of that.

 

Play in the steering box perhaps, or maybe the power steering pump is on its way out.
When my car is stone cold, it vibrates a little through the wheel, which stops once the fluid is warm.

 

I suppose it's possible, although one thing I found is the vibration isn't just in the steering wheel, it's in the whole body. It also occurred to me to put my hand on the outside when it was idling, sure enough I could feel it there too, except when it's in neutral.

 

Got my car back today, needed it for an appointment later. The droning and a good deal of the vibration when moving is pretty much gone. It will do it a tiny bit on rougher roads, but that's probably just the tires since on smoother roads it's nice and quiet. Also most of the creaking at lower speeds was caused by the bearing, it's gone too. The passenger door panel seems to do the rest of the creaking, but it doesn't seem like it would be a serious issue.

My mechanic also said the front transmission mount looks badly worn, I'll have it replaced later today or tomorrow morning. Considering that it also clunks when being put into reverse or drive, I think this might be the culprit. I'll know for sure later.

 

Just got it back yesterday and drove it around, and man what a difference. There still is some vibration through the steering wheel, but it's not nearly as bad as before. It also doesn't seem to be going through the body anymore, and the transmission isn't clunking when put into gear anymore either.

I would guess the other mounts could need replacing, although for money reasons that's likely not going to happen until next year.

 

And by next year I really meant next week. The vibration issue definitely got worse and I suspect the cold weather did them in and 2 were failing quickly, I decided to have all the remaining mounts replaced. That has made things better, but it isn't done. Sadly getting the mounts replaced, necessary though it was, severely depleted my savings. I'll have to wait a couple of paychecks before trying again to solve this problem, depending on what it is.

I've noticed a slight rattling while accelerating sometimes, almost like something is loose. I suspect it's related. Either the steering box or something else. I can't help but wonder if the catalytic converter might be the problem.

 

On ebay, go find yourself a GM shop manual for your car. The mounts are not that expensive or difficult to replace. The Haynes manual is OK but nothing beats a good ol shop manual specific to your vehicle. I have one for the Cutlass as well as one for my Twin Toros. I cannot express enough how much such a manual helps.

On the bad side, they can be difficult to read and navigate. The good side though is once you figure out HOW to read it, it gives you MANY solutions and tons of guidance. Once you figure out how to read them, if you are willing to do your own work, they will save you $$$ in the long run.

 

I already had the mounts replaced. That had to be done straight away because the cold was making them deteriorate very quickly. However, the reason I'm not able to do much on my own is because I don't have any tools and nowhere to work, I live in a large apartment complex and they don't like it when people work on their stuff. Can't say I blame them, last year some people tried fixing their dirtbike and made a huge mess in the parking lot. Fortunately my mechanic doesn't charge for problem diagnosis (if it gets repaired at his place) and if it's something really really simple like upping the idle a bit, at least for his regulars he won't charge if he isn't sure it will fix the problem. Whatever his faults are, there is genuine honesty.

Anyway, the vibration now feels very different from before, not just the magnitude but it feels very deep. Like I can hear a deep, regular pulsating. I guess the best comparison would be if you had one or more engine mounts totally fail and there was just a metal on metal connection. Now granted the engine mounts are no longer contributing to the problem, but something else is. Combine that with the rattle sound on acceleration, it would seem that something is loose and acting as a bridge between the chassis and the engine.

 

So it turns out the engine was misfiring because the recently installed fuel pump went out. Fortunately it occurred while it was being looked for the vibration so I didn't need a tow and it was replaced under warranty. Anyway, some bolts were tightened up and for a brief moment the vibration was substantially subdued, to the point where I declared good enough.........

And then a couple of miles down the road it started doing it again. It also started really struggling to go up even small hills, I had to depress the accelerator 1/2 to 2/3 of the way just to get it up to 40. Turns out it was misfiring yet again. This time there was one or two clogged fuel injectors, and running injector cleaner through it fixed the problem. However once again there is a rattle on acceleration and a lot of vibration on idle. I'm taking it back in a couple of days, I'm betting something that was tightened before had come loose. If the engine is running fine and the transmission is ok (I had them check it and the fluid is still pretty good) that doesn't leave too many other options.

 

The rattle this time wasn't something loose at all but rather evidently the water pump. It blew a seal and the bearings were starting to go, now that's been replaced the rattle is totally gone. The vibration is better, but there's still a fair amount of it coming through the steering wheel and to a lesser degree the front part of the floor. I'll have it looked at again after I get another paycheck or two.

 

Also sounds like you may need your fuel tank cleaned out or get a new one

 

That would explain why the fuel pump that just recently put in suddenly died. Good suggestion.

 

I finally was able to get it looked at again and it turns out the source of this intermittent heavy vibration has been the compressor for the air suspension system. Didn't even know it had one of those, but it does. I tried finding a mount for it, all signs point to that possibly being worn out, but I couldn't find one for this model year. Instead I had the rubber parts of it replaced and it did help a little, but it's still doing it. Eventually I'll have the suspension converted to a standard coil setup, but that's going to be quite a ways into the future because of the expense unless it breaks.

However even when the compressor isn't on there's still some vibration through the steering wheel, but I can't help but wonder if it's temperature related. It definitely does it less after it's been on the road for a while or on warmer days. So far I can't find any other cause for it, all the engine mounts have been replaced, the engine is running good, there doesn't seem to be anything touching the steering assembly, the engine accessories seem to be working fine. Is this normal?

 

The compressor on my '87 Olds 88 runs on startup, and from time to time during a trip.Loading up the trunk after taking my wife shopping will do it!.
However it doesn't run constantly, only for a few seconds now and again. A warning light comes on telling me it's operating too. Maybe you have a leaking shock or air line causing your compressor to run more than it should.
If you have a leaking shock then maybe it's a good time to convert to regular shocks and springs. Before you do this check out how much simply replacing the air shocks will cost. Last time I looked there wasn't much difference in the price of the shocks, you will new springs with regular shocks, and the labor costs will be the same.

Roger.

 

Mine doesn't run constantly either (I think), although I don't have an indicator light for when it comes on I can certainly feel it. However even when it isn't on there is still some steering wheel vibration, but not as much. Typically it turns on when it goes up or down hills. I do live in an area with a lot of hills, not sure if this indicates it has a leak or not. I will have it checked out when I have the chance.

 

One thing I've been noticing is when the temperature is stable for several days it hardly turns on at all, if there is a leak it's a very small one. This does make sense, in a closed system when the temp drops the pressure goes down as well. During the last weekend I didn't drive it at all and I noticed no sagging. I've never seen a warning light, where would it be on the light display? I haven't had it checked yet since some other issues cropped up.

As for the vibration, I'm convinced the cold is responsible for there being more vibration than during the summer. I've ridden in a couple of other people's cars and noticed a lot more vibration in their cars too. I guess the rubber just tends to stiffen up in the cold. I am updating the original post to provide a list of all the causes.

 

Could it be a bad torque converter?

 

I really hope not. Although the transmission has been checked the fluid is perfectly normal. Wouldn't something like that present other symptoms too?

 

And it turns out the lower control arm bushings were going bad, so bad they started causing other problems like a bucking feeling when there's a weight transfer and loose steering. Now that they've been replaced the vibration has gone down substantially. They've probably been going bad for quite a while too to be totally shot like this, likely it's been the source of that phantom vibration this whole time. Granted I haven't driven it much yet, I just got it back today, but so far it's better than before (it was HORRIBLE when I took it in). I also had them replace the sway bar bushings, since they were starting to deteriorate too. The big expensive project is going to be replacing all remaining bushes, it won't be cheap but since so many have already gone bad they likely will need to be pulled at some point this year anyway. Better to do it sooner than later.


EDIT: By the way, the struts were checked for leaks and they didn't find any, since I haven't noticed any sagging I'm not too surprised. Interestingly it doesn't have an indicator light for the compressor, although for some really weird reason it has one for airbags even though it's not equipped with any.