[fast_dave]

Just askin' @Johnwu62

Are you sure you have a turbo Abarth?

As written, your procedure for replacing the multi-air brick filter on your 500 (i.e. Lifting the engine) sounds an awful lot like filter replacement on a naturally asperated engine - NOT a turbo engine...

Reference link with pics and diagrams: https://www.fiat500usaforum.com/for...iming-cover-vs-multi-air-filter?36665-1-4-N-A-Timing-Cover-VS-Multi-Air-Filter=

When convenient, open the hood and take a pic of your entire engine bay and post it to this thread...

HTH -

 

[fast_dave]

Suggestion -

Replace the Vin Number at this link with your Vin Number so as to get your cars window sticker and thus establish pedigree. HTH -

Link: https://www.chrysler.com/hostd/windowsticker/getWindowStickerPdf.do?vin=JC1NFAEK8H0122974

 

[fast_dave]

@Johnwu62
The decoder you linked worked!

Based on previous searches, due to the decoder I linked not working, and what you described with the complexity of changing your brick filter, I believe that you have a very early build Abarth that used a "naturally/normally" asperated engine mount.

Since you have 140,000 trouble free miles, start simple with what you wrote in post 11.
Pay close attention to the spark plug gaps.

Ensure that all spark plug holes/threads are clean. Use a high nap cotton rag soaked in carb cleaner and clean up the spark plug threads in the head. A rifle/shotgun cleaning rod and patch holder can be very effective. Additionally a brass (soft) bore brush to get deep into the threads.

Use a light coat of dielectric grease on ONLY the porcelain body and connection tip of the spark plug.
Do not use dielectric grease on the spark plug threads!

Look for oil pooled in the #4 spark plug hole, which would come from a faulty O Ring at the base of the Air Oil Separator. Oil can also pool in the AOS. You can remove it, spray it out with aerosol carb cleaner, and let it dry out in a cardboard box. Change the orientation as it's drying so that residual oil drains out into the box. Remove the PCV Valve and spray it out with the aerosol carb cleaner. When you shake it, you should hear it "rattle" - meaning it's good to go.
LINK: Is there a part number for the o-ring/gasket on the...

Hope that helps, good luck, and report back!

PS - If you haven't already done it, you're due for a coolant changed as it's reached the end of it's service life, both in years and miles.

Also, carefully monitor your coolant level in the overflow tank - slight misfiring, especially in the morning until fully warmed up, may be an indication of a head gasket issue.

 

[fast_dave]

@Johnwu62

For further clarification - The AOS (Air Oil Separator) box doesn't have any moving parts in it - it's just a series of baffles that routs the crankcase air through a maze, with the hopes that as the crankcase air is moving through it, it will come in contact with the baffles, and that "action" will remove/separate the vaporized oil within the crankcase air.

The vaporized oil settles in the bottom of the various baffle compartments. Remove the AOS, and over the course of an afternoon, spray Aerosol Carb Cleaner in it's various openings. Place the AOS in a cardboard box, and every couple of hours change it's orientation as to which "hole" is facing the bottom of the cardboard box. As hours pass by, you will see used oil drain out of the AOS and into the bottom of the cardboard box. There's no need to buy a new AOS (or a new PCV Valve for that matter). Hope that helps - any other questions, ask away

 

[fast_dave]

Hey @Johnwu62

156,000 miles, AOS sludged & PCV Clogged, and the engine misfiring for 10 - 20 seconds on the first cold start of the day.

Immediately two thoughts that pop up when reviewing these three parameters.

Starting about 2017, forum members on the (then) three main forums started experiencing head and block (piston) problems that showed that the 10,000 engine oil change was way too long. That's the short version. Moving on - again the short version - the AOS and PCV Valve "clean out and regulate" crankcase BLOW BY fumes/pressure. So it sounds like the previous owner may have used the factory oil change schedule on your hyperactive turbo engine. Your sludged AOS and stuck PVC tell the story. So, the start-up misfiring could be attributed to your valve guide seals could be worn and dripping oil into the combustion chamber overnight, actual valve guides could be worn and dripping oil into the combustion chamber overnight, or piston rings being worn. A compression test would help you further evaluate what, if anything, is going on in the head and block.

You've also written that your coolant level is staying regular. When the engine is cold, use a Sharpie to make a horizontal "witness mark" on the overflow tank EXACTLY where the coolant level is. Carefully monitor over the course of 2-3 weeks. If in that short timeframe it falls even slightly below the black level mark, you have coolant escaping somewhere.

In closing - where are you, where did the car come from, and what style of driving has the car been exposed to?
Did you ever get any maintenance paperwork with the car?

Ambient temperatures and city VS highway driving also help establish the complete picture.

Hope that helps -

f_d

PS - Keeping things easy - in addition to witness marking your overflow tank, you could also move your Cyl 3 Ignition Coil to another cylinder and see if the misfire "moves" to the swapped out cylinder. If it does, you have a bad #3 coil.

 

[fast_dave]

@Johnwu62

10 years of ownership - welcome to the forum!

OK - upon quick review, I see from a previous post in this thread that you have already replaced the Cyl 3 ignition coil.

So, it's possible that due that you're getting a bad ground on #3 due to some sort of build up on the sparkplug threads that are in the head. So, keeping it cheap and easy, try removing the #3 spark plug and cleaning the sparkplug threads in the head / #3 cylinder.

Use a round brass brush - i.e. 410 shotgun or .45 caliber and carb cleaner solvent, followed up by a high nap cotton patch material (inside of a tube sock).

On this particular engine - DO NOT use any di-electric grease on the spark plug threads! Use it only on the spark plug contact tip where it connects to the coil and sparingly on the porcelain body of the spark plug. Bottom line is you want to avoid the grease dripping down onto the threads.

Good luck and report back!