An engine vibration that’s neither a misfire nor a problematic mount may take some time to find. Suggest to briefly post everything engine-related that has changed, including how many days ago the change(s) occurred, since the last time there was no similar vibration.
Please George, no! We’re already at post #62.
That’s why I’m asking for a summary, … lol … can you think of any reason for OP’s engine vibration suddenly developing other than a misfire?
UPDATE
So, they checked the rear mount, and it had some cracks in it, so they replaced it. Said the side mounts both looked fine. So front and rear mounts are now new. So I picked up the car, as there’s not much else they could do.
So, basically, right now it has strong vibrations at idle when in Drive or Reverse (but not Park). And the vibrations continue (though much less) when driving slowly. But once you get over a few miles per hour the drive is smooth. No vibrations.
That would SEEM to be an air/fuel issue (based on my very limited understanding of car mechanics). But he said they checked the air/fuel ratio when the car was idling, and it was correct (numbers noted in previous post).
So I don’t know what else it could be. I’m just glad it doesn’t do it while I’m driving.
That would be easy to do.
9/16 - 106,659 miles:
No vibrations. Car had emission leak from fuel tank which was throwing a code, and catalytic converter was throwing a code. Shop ordered new fuel tank from salvage yard, but it also had a leak, so they just repaired the leak in the tank’s rollover valve.
Fuel pump had been making noise for a while, so they replaced fuel pump when the fuel tank repair was done.
Catalytic converter was replaced. Oxygen sensors broke when they were replacing cat, so they replaced the oxygen sensors.
After replacing cat, fuel gauge stopped working properly. Checked all outputs from the fuel pump, everything was fine. Checked electrical inputs, etc., all fine. So they replaced cluster with a new used cluster.
10/23 - 106,760 miles:
New catalytic converter made noise when accelerating. Checked everything, looked for leaks, replaced gaskets. Nothing fixed the problem. They determined that the problem was the exhaust manifold gasket, as they found a small leak from it. Replaced exhaust manifold gasket.
Valve cover gaskets had been leaking for some time, so replaced those as well.
Replacing exhaust manifold gasket didn’t stop the noise, so they replaced the cat with another catalytic converter, and that solved the problem.
Vibrations were first noticed after picking up the car after this work was done.
Thanks!
Nope. I wouldnt hazard a guess without ALL the appropriate data. Frankly, with the age of this van, it’s simply not worth it to track something like this down.
What was the most recent date your car had no vibrations?
Was it 10.1.23 at 106,760 miles?
If before 10.1.23 there were no vibrations, why did you include the changes all the way back to Sept 2016?
What was the most recent date your car had no vibrations?
Was it 10.1.23 at 106,760 miles?
That was actually meant to be 10/23/23. And, yes, right before they replaced the manifold gasket, there were no vibrations.
If before 10.1.23 there were no vibrations, why did you include the changes all the way back to Sept 2016?
I must’ve misunderstood what you were asking for. Since you were asking for the number of days since the changes were made, I thought you were implying that recent changes might take a little time to manifest. So I included changes that had been done a few weeks prior to the vibrations appearing, in case they were significant.
And, no, that wasn’t Sept 2016. That was 9/16/23. Thanks.
Confusing. Suggest to repost the vehicle repair history, this time starting from the most recent date there were no vibrations. There’s no need to go further back than that. Brief post, please. Only what was done, not why, or what else they checked.
Sorry about the confusion!
Suggest to repost the vehicle repair history, this time starting from the most recent date there were no vibrations.
That’s what I posted. The most recent date that repairs were done when there were no vibrations was 9/16/23, and the repairs I listed in the previous post was what was done (fuel tank rollover valve leak repair; fuel pump replacement; catalytic converter replacement; oxygen sensor replacement; instrument cluster replacement).
Then on 10/23/23 I returned for the noise that the new catalytic converter was making, and they replaced the valve cover gaskets, exhaust manifold gasket, and installed a new cat. It was after those repairs were done that the vibrations started.
Then today they replaced the front and rear engine mounts, but that didn’t address the issue. They said that the side mounts looked fine.
You seem to be contradicting yourself.
Sorry for not being clear!
9/16/23 there were no vibrations, either before or after the repairs were done.
10/23/23 there were no vibrations before the repairs were done. Vibrations were first noticed after the repairs were done on that date.
Sometimes with older cars with lots of miles, they just make noises.
Well there is always a reason, it doesn’t “just happen for no reason”, but if nothing appears to be wrong, not much you can do. You will drive yourself nuts, and spend money on parts that don’t really need to be replaced. Not worth spending the money or time, especially on an older car that his high mileage that may not be worth much. You will spend more money on repairs than the car is worth. If no major side effects exist from the vibration with no apparent cause, might just want to ignore it.
Yeah, that’s the plan. Unless something else comes to mind. Not much else I can do. At least the car actually needed front and rear engine mounts, so it wasn’t money wasted. And, like I said, at least it doesn’t do it while I’m driving, just while idling.
Just disappointing that you go in for what should be a simple repair, and you leave with your car having an apparently unfixable problem. 
But like I said to the service manager before I left today:
“I’m not leaving here with a car with a strong vibration while idling. I’m leaving here today with a car with a built-in massage chair!”
Are you taking this to the same shop or are these done at different shops?
Does the vehicle have to be moving to feel the vibrations?
You don’t feel the vibrations in neutral or park, but do you feel them as soon as you put it in gear but NOT moving?
Is there a clunk sound when you put it in drive or reverse, or if switching between drive and reverse?
Here is where I’m going with this. If the same shop, sounds like they are just firing the parts cannon at it. Second if the engine is smooth in neutral and park but vibrates in gear and not running, I’d suspect a cracked flex plate or they used a solid pipe instead of the flex pipe when they replaced the cat.
Are you taking this to the same shop or are these done at different shops?
This was all done at the same shop. I brought it back there to see if it was anything related to the recent work they had done, so they could make it right. Now that they’ve said they don’t see what else it could be, I’m done with the shop.
I contacted a semi-retired mechanic who does some work out of his home, who worked on my car years ago and did a good job. He’s going to take a look at it next week.
He thinks it could be related to the valve cover replacement and maybe something didn’t get reconnected properly. I mentioned to him what the shop said about the air/fuel mixture being correct, etc. He also mentioned it could be a dirty throttle body. I mentioned that the shop said that if it had been dirty when they were in there, they would have cleaned it (but I don’t know if that’s actually true). So he’s going to look at it next week. I’m a bit hopeful.
Does the vehicle have to be moving to feel the vibrations?
No, actually the opposite. The vibrations are only felt when it’s standing still and idling. In Park you can feel them a little. But in Drive or Reverse (with brake pressed) they’re very strong.
Then, when you start to go, they lessen.
The, once you’re above a few miles an hour, the vibrations are gone.
You don’t feel the vibrations in neutral or park, but do you feel them as soon as you put it in gear but NOT moving?
Correct.
Though, actually, I do feel them a little in Neutral or Park, but not much. Earlier I said they were gone in Neutral or Park after they replaced the front engine mount. But then later when I tested it I could feel them. So they’re there’ a little, but slight.
Is there a clunk sound when you put it in drive or reverse, or if switching between drive and reverse?
No, not at all. No clunk sound, neither before the engine mounts were replaced nor afterwards.
Here is where I’m going with this. If the same shop, sounds like they are just firing the parts cannon at it. Second if the engine is smooth in neutral and park but vibrates in gear and not running, I’d suspect a cracked flex plate or they used a solid pipe instead of the flex pipe when they replaced the cat.
Well, the pipe was the one that came with the kit, so I would assume it would be the correct pipe.
But, yeah, about throwing parts at it.
I mean, earlier, when I first replaced the cat and it was making a noise, they checked everything, couldn’t find a problem. They did find a tiny leak from the exhaust manifold gasket, and said, “It has to be the exhaust manifold gasket.” So I paid to have that replaced. Turns out that wasn’t the source of the noise.
But then they used a different catalytic converter, and the noise was gone. So the problem was the cat.
So, this time, when the vibrations didn’t go away after they replaced the front engine mount, the service manager, again, said in similar way, “Well, the only thing it could be is the other engine mounts. They have never been replaced and they’re old and worn.”
And I basically said, “Listen, I’m not going to throw money at it again. Last time, the mechanic said, ‘The only thing is could be is the manifold gasket,’ so I paid to have that replaced, but it turned out that wasn’t it. I’m not going to throw money at it again and pay to have all four engine mounts replaced because ‘that’s the only thing it could be’ – especially since the vibrations didn’t exist before the repairs were done, so it’s unlikely that the engine mounts just all of a sudden went out.”
But then they checked the rear engine mount and it had cracks in it, so they replaced it. Whether or not it actually needed to be replaced, I don’t know. But it’s fine they ended up replacing the front and rear engine mounts. But I wasn’t going to spend hundreds of dollars more to replace the side mounts, especially when he said they looked fine.
Thanks for your input! I’ll mention to the mechanic next week what you said about the cracked flex plate or solid pipe.
Checking throttle body is not part of routine “free courtesy check”. So I doubt they checked it. Unless they directly told they looked at it and it was clean. It wouldn’t have been necessary to check it to replace the valve cover gasket or exhaust manifold gasket, at least the cars I have worked on. They would have had no reason to look at it to replace those gaskets.
Also, don’t know about this car. But I presume it’s not throttle body injected. Just saying that if it was, and you use good quality fuel, then don’t need to worry about throttle body being dirty. The gasoline would keep it clean.
Probably good idea to take it to a different mechanic to check. Especially if you trust him, and won’t charge you to look at it.
Also sense you have the car back. Is it leaking oil from the valve cover?
But yes, on a car this old, I assume high mileage and probably not worth much (I drive a car that you can describe as such myself), things with no apparent cause or negative impacts, might be best to “just ignore” until it’s more obvious what the problem is.
Hope this second mechanic can fix the problem for you.
Maybe I was thinking of something else when I talked to the service manager. I don’t know. It was something that they would have seen when they changed the valve cover gaskets. Maybe not the throttle body. Maybe it was a valve of some sort. Anyway, the service manager said they would have cleaned it if they had seen it was dirty when they changed the valve cover gaskets.
No, I didn’t see any oil leak when I checked.
Yes, indeed. And, as I said, at least it only happens when idling. So, you know, count your blessings…
It’ll be good to have the other mechanic look at it anyway. I don’t think I’ve changed my PCV valve, so I think he’s going to do that while he’s looking for the cause of the rough idle.
Thanks!
I don’t quite agree with your idea that using good quality would prevent a throttle body from getting dirty
I have seen many dirty throttle bodies that needed a cleaning and relearn, in spite of high quality fuel being used
What’s your reasoning?
Might be talking about a wet TBI (90’s), and not a dry intake multiport injection (like the OP’s), where the fuel sprays the throttle blades, unlike the dry throttle body where of course it does not…
Other than that, I don’t have a clue what YM3 means… lol
My bad. Off by a decade. Yea I highly doubt this car has TBI. Where the fuel injection is on the throttle body, and the gasoline helps keep it clean.