erratic vibration at idol

I'm new to this so please bare with me. I worked on my Mother's 2005 Dodge Neon with a 4 cyl engine to attempt to fix an erratic engine vibration at idol problem with no success. No DTC is given so that didn't help. I did not own a scanner at the time, but I purchased a Snap-on Solus Pro scanner with the 16.4 version on it and wanted to know if I could use it to find what's causing this . Can anyone point me in the direction of where to start if I can use it without a DTC? I don't want to be a parts changer anymore. I replaced spark plugs & wires, fuel filter, fuel pump and timing belt.Thank You. RickD. in San Antonio, Tx.

Hi Rick, welcome to the forum!
Is the vibration worse in gear than it is in park?
I'm thinking of the possibility of junk engine mounts considering there was no dtc stored. If you can lift the engine with a large bar and the vibration gets better, suspect an engine mount.

You can absolutely use the Solus Pro to check data pids to help point you In the right direction, even if there are no trouble codes!

If you haven't already, you might want to consider signing up for the free trial of Scanner Danner Premium where you'll find hands down, the best instructional series on the use of your Solus Pro.
Solus Pro Training: www.youtube.com/playlist?list=PLM4TD8VJ3...BPSJiW2yINRfsZxGv1KL

Erratic idle can be caused by a vacuum leak, you can look at fuel trims if the fuel trims are adding fuel at idle but adding less at higher rpm then it could be a vacuum leak. The water test is a good test for a vacuum leaks.




The other things to look at are the idle speed control valve and egr valve and also cleaning the throttlebody.

I actually replaced all the motor mounts and I also replaced the intake to air filter housing connecting hose. The large one that looks like an accordion, because it had a large hole in it. I have not had a chance to hook up the Solus pro to it. What should I look for when I do?

I bought a toyota corolla ce with a 1.8 engine around 3 weeks ago and it also vibrates at idol. I connected the solus pro to it and reviewed the Pid's. The Pid's are as follows: RPM - 748, ST FT 2.3 - 3, LT FT 5.4, IGN ADV 17.0 - 18.0, MAF (g/s) 1.84, Throttle Pos 16-17 and Inj (ms) 2.3. I don't know what the normal Pid readings should be so can anyone tell me if any of these Pids can be the cause for a rough idol. No DTC found. Thanks in advance.

RickD. wrote: I bought a toyota corolla ce with a 1.8 engine around 3 weeks ago and it also vibrates at idol. I connected the solus pro to it and reviewed the Pid's. The Pid's are as follows: RPM - 748, ST FT 2.3 - 3, LT FT 5.4, IGN ADV 17.0 - 18.0, MAF (g/s) 1.84, Throttle Pos 16-17 and Inj (ms) 2.3. I don't know what the normal Pid readings should be so can anyone tell me if any of these Pids can be the cause for a rough idol. No DTC found. Thanks in advance.

Sorry, I'm confused now :blush:
Are these data pid values for the Neon or another Corolla? I don't see any smoking gun there...
I'm also still kind of unclear about the exact symptom. You called it "an erratic engine vibration at idle".
The vibration part is what got me thinking motor mounts. When you say erratic, is the rpm changing drastically? Or is this like more of a rough running, misfiring condition?
Sorry if I seem like I'm nit-picking, it's just kind of hard to get a sense for what the car is doing from where I'm sitting;)
I like Andy's vacuum leak testing suggestion. I'm pretty sure the Neons of that vintage had the throttle body on the air box and not on the intake. Since you were just in there changing the big air breather tube, it may be worth a second look see to make sure all the clamps are nice and tight, any small tubes or lines are all securely fastened and that the air cleaner box itself is sealed nice and proper.
Any air leaks in any of these areas will not be accounted for by the MAF, and cause rough running or stalling.

Sorry for confusing you. I will keep looking at the solus pro videos to find out where I can get the info I need. I will post what I find. Thank You.