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In 2014, I got a new engine put in from a 2005 Kia Rio. The engine had 25,000 miles on it, I've put about 5-6 thousand on it since then.
I had created a thread back then to figure out if a different engine was worth it. In the end, it was actually cheaper for me to get a "new" engine than plunk down a whole lot of money for a new car. Engine got me from Maine all the way across the U.S. to the west coast without issue. That was about 3800 miles, taking a southern route due to winter and not wanting to take a Kia Rio across the Rockies.
Got to the west coast. About a week later, got an oil change. About one mile down the road, for the first time ever, when I was sitting at a red light, the car started shaking in idle in drive with foot on brake.
Fast forward to the last 2 months:
Because I did my work from home and did not have to drive that much, I didn't get anything done until recently.
In the last 2 months I have had the following done:
New engine mounts, from Kia. One was broken, one was almost broken, one was fine. Changed all 3 anyway.
New a/c compressor, and had it filled with freon and charged.
New battery. (Had a new battery last year, but apparently it was bad and had to get a new one, still under warranty, thankfully.)
New alternator. Mechanic replaced 3 belts (alternator belt, power steering, and a/c - is what he said.)
Drums and bearings in rear brakes.
Throttle body was cleaned out. Also was realigned by different mechanic when first mechanic did not align it properly. (Is what was said - have no idea what that means - I'm not a mechanic.)
IAC valve was cleaned out.
New air intake "boot" that was ripped.
New air filter.
New spark plugs - they said my old ones were bad.
New brake booster (because shaking happened when foot on brake, even in park and neutral although shaking was nowhere near as bad when in park or neutral since engine is not under load in park or neutral.)
New air hose (whatever it's called that is somewhere near the brake booster area - not sure official name.)
Ok, so got all of that done over the last 2 months. The brake booster, new air hose (near that area), and new spark plugs were just done this week.
Now when I drive, if I'm at idle at a stop light, car is back to normal. Because it's a 2004, of course it's going to have a very, very slight shaking - it's not going to be nice and quiet like a new car.
Mechanic took it on a test drive, got it all warmed up, and said "difference was night and day" and that can now drive and be at stop lights with foot on brake in drive and no shaking.
That much is true. But he didn't test it out fully, going through the scenarios I told him about before any fixes.
So I test drove it after they told me it was fixed, and I put it through the situations I had bad shaking before.
Drove and stopped at stop lights, in drive, foot on brake - no problem.
Went through a drive through to get a large drink, and to test car when idling for a long while, not just at a stop light.
Just a few minutes into waiting in this line, I tested various ways:
Car in drive, foot on brake
Car in neutral, foot on brake
Car in neutral, ebrake on
Car in park, foot on brake
Car in park, ebrake on
And in each one of those above, I tried with the a/c on and without the a/c on.
Car in drive, foot on brake - seemed okay.
Car in neutral, foot on brake - car did not like that. It started to shake badly.
Car in park, foot on brake - car shook, sounded like it would die, and I sat there and watched the RPMs drop while idling.
Car in neutral, ebrake on - seemed fine, but put a/c on, get some shaking.
Car in park, ebrake on with a/c on, car shaking.
So, driving it on city streets and coming to red lights, in drive, foot in brake, that part was fixed. But under load, with a/c on, something is going wrong. I've had 3 mechanics look at this car. One stated it was engine mounts. (That was back in 2015, and since I had just moved, didn't have the chunk of change to change them, plus do work at home, as stated above. Total miles driven since then is only about 500, about 300 of them being last year when I had to do a drive cycle to pass inspection after changing dead battery.)
The 2nd mechanic cleaned the throttle body, changed the engine mounts. We had tried after market engine mounts first, nothing changed, and mechanic said he didn't like how "loose" they were. So we ordered Kia mounts, which cost a bit more, and he seemed satisfied, but the shaking did not go away. He then did a check for vacuum leaks using a smoke machine. He said he found no leaks, and he said because he had already spent so much time on the car trying to find anything in the engine causing this, and could not find anything, he just didn't want to keep working on it.
Third mechanic discovered that there was a leak in a hose, and that the brake booster was "leaking" (not sure what word he used) from the diaphragm. (Or something like that...they mentioned those words "diaphragm" and "leaking" - but it is possible that I'm messing up exactly what they said so if that's incorrect, that's on me, not mechanic.)
As stated, he replaced the brake booster, replaced that air hose that he said he could clearly see "no tools have been anywhere near that clamp in a long time", and they did the spark plugs since the others were bad.
Does it have anything at all to do with the spark plugs? Is it something with the compressor they just changed? Is there something faulty with wiring? Is there somehow some issue with battery and alternator?
When I brought it back to the mechanic, I explained what happened. He wants me to bring the car back on Tuesday to inspect further. I'm just looking for ideas on what it could be. He mentioned something about "selinoid" (however that is spelled, and whatever that is) could be "leaking" or something like that.
Cleaning a TB doesn’t change the fact you may have a TPS that’s starting to act up. I personally thing cleaning TBs is a little bs repair.
Engine mounts won’t make the engine run rough. You’ll get clunking sounds and the engine will move when you hit the gas because it will torque over.
You can hang a engine level on a chain and start it and it should run smoothly. Motor mounts hold a engine in place.
You need someone who has a real scanner to check the issue. These guys are just guessing at the fix
The engine mounts are explained above. I got new ones, and I don't believe it's the engine mounts causing any of these issues. The old mounts, the after market mounts, and the new Kia engine mounts have not resolved all of the shaking. Yes, one was broken, one was close, and the last one fine so I got them all changed anyway, but it had nothing at all to do with any shaking.
They have scanned. They get no codes. When I called Kia to see if they had more advanced, they told me that KIA considers my vehicle 'obsolete' since it's beyond the 10 year/100,000 mile warranty, so even the Kia mechanics no longer have the ability to read anything beyond what any other mechanic could read. (Called 2 KIA places, both said the same thing.)
"These guys" are not just "guessing" at the fix because they failed to scan...they did scan. The other mechanic scanned. Not a single error code gets thrown. Every single mechanic, including both KIA places said they would have to go, part by part, replacing things, to figure it out.
Current mechanic is the only one who found the air hose causing a vacuum leak, found the brake booster diaphragm causing a leak...said you could hear the air hissing when he did..whatever it was he did..push the brake or whatever he said, while in the shop. He did stop the shaking while idle while in drive with foot on the brake, so he's figured out a hell of a lot more than anyone else. Anyone else is telling me that they would only be guessing.
The engine mounts are explained above. I got new ones, and I don't believe it's the engine mounts causing any of these issues. The old mounts, the after market mounts, and the new Kia engine mounts have not resolved all of the shaking. Yes, one was broken, one was close, and the last one fine so I got them all changed anyway, but it had nothing at all to do with any shaking.
They have scanned. They get no codes. When I called Kia to see if they had more advanced, they told me that KIA considers my vehicle 'obsolete' since it's beyond the 10 year/100,000 mile warranty, so even the Kia mechanics no longer have the ability to read anything beyond what any other mechanic could read. (Called 2 KIA places, both said the same thing.)
"These guys" are not just "guessing" at the fix because they failed to scan...they did scan. The other mechanic scanned. Not a single error code gets thrown. Every single mechanic, including both KIA places said they would have to go, part by part, replacing things, to figure it out.
Current mechanic is the only one who found the air hose causing a vacuum leak, found the brake booster diaphragm causing a leak...said you could hear the air hissing when he did..whatever it was he did..push the brake or whatever he said, while in the shop. He did stop the shaking while idle while in drive with foot on the brake, so he's figured out a hell of a lot more than anyone else. Anyone else is telling me that they would only be guessing.
Just looked that up. Also looked up what TPS means.
The engine isn't shaking when I'm going faster than idle. Even if going 30, it doesn't shake, it's only when idle.
Will ask mechanic about both of those. Parts wise, neither is expensive. Labor is another story.
Edit: I forgot to add that when in drive at idle, I hear a chirping noise, but when I put it into neutral or park, the noise immediately goes away. No clue what that is.
If the engine is shaking, there are typically two reasons:
1) It's idling too low.
Lower idle means it will vibrate more. When you turn the A/C on it adds more load to the engine, which will drop your idle speed. The computer usually compensates by opening up the throttle plate or idle air control valve a little when the A/C compressor is running. There are a variety of reasons this might not be working properly, which could include faulty sensors, a wire not plugged in after the engine was swapped, some kind of incompatibility or difference between the old and new etc. etc.
2) If the idle is at normal RPM, the engine is either:
a) Out of balance - A bad harmonic damper could indeed cause it to idle rough. Or, maybe the new engine doesn't have the same balance shafts as the old one. Or perhaps it uses a different flywheel. Basically, anything in the rotating assembly of the engine could cause it to vibrate.
or b) Not properly held in place - e.g. one of the engine mounts is broken (you said they were replaced), perhaps one is not bolted down properly, was not installed properly, etc.
If the engine is shaking, there are typically two reasons:
1) It's idling too low.
Lower idle means it will vibrate more. When you turn the A/C on it adds more load to the engine, which will drop your idle speed. The computer usually compensates by opening up the throttle plate or idle air control valve a little when the A/C compressor is running. There are a variety of reasons this might not be working properly, which could include faulty sensors, a wire not plugged in after the engine was swapped, some kind of incompatibility or difference between the old and new etc. etc.
2) If the idle is at normal RPM, the engine is either:
a) Out of balance - A bad harmonic damper could indeed cause it to idle rough. Or, maybe the new engine doesn't have the same balance shafts as the old one. Or perhaps it uses a different flywheel. Basically, anything in the rotating assembly of the engine could cause it to vibrate.
or b) Not properly held in place - e.g. one of the engine mounts is broken (you said they were replaced), perhaps one is not bolted down properly, was not installed properly, etc.
Which sensors?
The engine was "swapped" in 2014, and has about 5-6000 miles on it. What's going on now has nothing to do with someone not plugging in a wire or incompatibility. The compatibility was checked before ever ordering the engine - so it's not that.
The idle doesn't stay at normal if I sit there and watch it drop while idling when in park with the a/c turned on.
And again, the car only shakes while in idle with the a/c on. It does not shake at any other time.
Ok, so you're seeing a large drop in idle speed? That's why it's shaking.
I couldn't tell you why, I can just give you some thoughts on the topic.
Your car may or may not have an idle air control valve. When vehicles became drive-by-wire they did away with the valves as the computer could just open the throttle plate a bit to compensate for low idle. Older IACVs were combination mechanical (like a car's thermostat, used a phase change material) and electrical, allowing small changes to be made to the amount of air being let it. If it has an IACV the valve probably failed. If it's drive-by-wire, for whatever reason the computer has suddenly chosen not to make that compensation. Chances are good some critical piece of information it needs is now faulty - maybe a MAF sensor or throttle position sensor (TPS)?
Ok, so you're seeing a large drop in idle speed? That's why it's shaking.
I couldn't tell you why, I can just give you some thoughts on the topic.
Your car may or may not have an idle air control valve. When vehicles became drive-by-wire they did away with the valves as the computer could just open the throttle plate a bit to compensate for low idle. Older IACVs were combination mechanical (like a car's thermostat, used a phase change material) and electrical, allowing small changes to be made to the amount of air being let it. If it has an IACV the valve probably failed. If it's drive-by-wire, for whatever reason the computer has suddenly chosen not to make that compensation. Chances are good some critical piece of information it needs is now faulty - maybe a MAF sensor or throttle position sensor (TPS)?
Actually, before anything was replaced this last week, the idle didn't drop. It would start out cold around 1000, and by the time it was warm, the idle was about 650ish. Despite shaking or a/c on, the idle didn't drop down. When it was cold and idling anywhere above 800, there was no shaking at all, even in drive with foot on brake while idling.
However, after the fix, I can now sit at a stop light in drive with foot on the brake and not feel the crazy shaking and the idle doesn't drop. If I turn on the a/c, it shakes very badly, but I did not notice the idle drop. When it was in park, with foot on brake and a/c on, I saw the idle go down, and the shaking got worse.
What used to happen: In drive, foot on brake at stoplight - shaking. In park or neutral with ebrake on - no shaking. In park or neutral with foot on brake - some shaking, but not like when in drive. If a/c on, it would shake more in all situations, but again, when in park and neutral, obviously not as much because it wasn't under load as much as it is when in drive.
What now happens is what I described.
Something is off - something got missed, maybe the new spark plugs are wrong? Maybe it has something to do with the throttle body? What the heck is a selinoid, or whatever they said and how is that spelled? Is that a possibility? I'm trying to get as many possibilities to throw at the mechanic. He's had 30 years of experience, and again, he was the only one who found the vacuum leak in that one air hose, the only one to find out the booster was leaking - so he's done a way better job than anyone else has. But I'm trying to find solutions instead of doing this one part at a time like KIA told me they would do if I brought it into them.
Yes, my car does have an IAC valve. It was cleaned. Nothing changed. No check engine light comes on, no code is thrown - but maybe it needs replacement...I don't know.
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