Piston Slap: All Abarth That Bad Diagnosis!

Sajeev Mehta
by Sajeev Mehta
piston slap all abarth that bad diagnosis
Chris Writes:

Greetings Sajeev!

We’ve just been informed that our 2013 Fiat 500 Abarth has 180-180-180-20 compression and likely needs a new engine. Options are somewhat clouded by a remaining note of about $6,000.

Looks like this boils down to:

  1. Get out, despite the sunk costs and remaining note, and get into a

    more conventional car.
  2. Go the used engine route to save a few $$.
  3. Source a new engine and commit for ~5/6 years +

The SU (spousal unit) is the primary driver and adores the car. I drive it infrequently and find it tedious. It has about 80,000 miles and has been OK on other maintenance issues. All work will be done by a pro – this is so far over my head, mechanically, that there’s just no way – and the car is a daily driver, so commute/mobility issues create additional urgency.


Before Sajeev’s slow-ass self could respond…

Greetings, again, Sajeev:

This is the epilogue of the Fiat 500 Abarth engine swap saga that we exchanged email about last week.

As I was thinking over the options before me, I realized what I really needed was a better diagnosis. I spoke with the service writer at the Fiat dealership nearby and he assured me that the engine replacement was at minimum an over-reaction, at maximum a tragic mistake-in-waiting. Clearly needing to see the car to make a conclusive decision, he said that the need for any internal engine work, or even head/valve work, was remote, and the issue was most likely a sensor or a solenoid that was inoperative due to…we’ll let you know.

I called the independent shop where this saga started and urged a slow-down in this seeming rush to judgement. The service writer – who I’ve worked with for nearly 20 years – started at square one and found a cracked insulator on one spark plug. After a borescope inspection of the no-compression cylinder and replacement of all 4 plugs, then resetting various codes, we’re back in business. A pre-emptive oil change was also performed just to be sure that fuel contamination would not be an issue. 7,000 plus RPM and lots ‘o boost make that very prudent step one I could endorse without much deliberation.

The verdict is in: the car runs like new, starts and idles fine, and runs to the redline – and full boost – eagerly. A win after much hand-wringing.

The big lesson is, a relationship with the shop helps, taking charge helps, getting the facts (i.e. a full and factual diagnosis) before any repair is started really helps.

Sajeev concludes:

Son, I wish every automotive malady (both here and in my own garage) solved itself so effortlessly. Perhaps I should add something

You should ask that shop where the “180-180-180-20 compression” test result came from. Because that’s a seriously misguided diagnosis if new plugs fixed a (seemingly obvious?) misfire. Since you have a long history with them (or just the service writer?) they should be made aware they put you through a fair bit of stress for no good reason. And I mean no good reason at all: because I’m having a hard time finding a correlation between low compression readings being resolved by new spark plugs.

Perhaps their compression tester bit the dust after testing the last cylinder?

So to you, Best and Brightest: what’s up with that initial compression test?

[Image: FCA]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Join the conversation
3 of 73 comments
  • R Henry R Henry on May 26, 2019

    500 owner was a victim of outright fraud.

    • HotPotato HotPotato on May 28, 2019

      Smells like it, especially since the service writer had to sneak around the shop owner to do the right thing.

  • Don1967 Don1967 on May 28, 2019

    Confirmation bias. Your hunch says bad compression in one cylinder, causing you to accept a freakishly low reading instead of verifying your work.

  • Nrd515 I bought an '88 S10 Blazer with the 4.3. We had it 4 years and put just about 48K on it with a bunch of trips to Nebraska and S. Dakota to see relatives. It had a couple of minor issues when new, a piece of trim fell off the first day, and it had a seriously big oil leak soon after we got it. The amazinly tiny starter failed at about 40K, it was fixed under some sort of secret warranty and we got a new Silverado as a loaner. Other than that, and a couple of tires that blew when I ran over some junk on the road, it was a rock. I hated the dash instrumentation, and being built like a gorilla, it was about an inch and a half too narrow for my giant shoulders, but it drove fine, and was my second most trouble free vehicle ever, only beaten by my '82 K5 Blazer, which had zero issues for nearly 50K miles. We sold the S10 to a friend, who had it over 20 years and over 400,000 miles on the original short block! It had a couple of transmissions, a couple of valve jobs, a rear end rebuild at 300K, was stolen and vandalized twice, cut open like a tin can when a diabetic truck driver passed out(We were all impressed at the lack of rust inside the rear quarters at almost 10 years old, and it just went on and on. Ziebart did a good job on that Blazer. All three of his sons learned to drive in it, and it was only sent to the boneyard when the area above the windshield had rusted to the point it was like taking a shower when it rained. He now has a Jeep that he's put a ton of money into. He says he misses the S10's reliablity a lot these days, the Jeep is in the shop a lot.
  • Jeff S Most densely populated areas have emission testing and removing catalytic converters and altering pollution devices will cause your vehicle to fail emission testing which could effect renewing license plates. In less populated areas where emission testing is not done there would probably not be any legal consequences and the converter could either be removed or gutted both without having to buy specific parts for bypassing emissions. Tampering with emission systems would make it harder to resell a vehicle but if you plan on keeping the vehicle and literally running it till the wheels fall off there is not much that can be done if there is no emission testing. I did have a cat removed on a car long before mandatory emission testing and it did get better mpgs and it ran better. Also had a cat gutted on my S-10 which was close to 20 years old which increased performance and efficiency but that was in a state that did not require emission testing just that reformulated gas be sold during the Summer months. I would probably not do it again because after market converters are not that expensive on older S-10s compared to many of the newer vehicles. On newer vehicles it can effect other systems that are related to the operating and the running of the vehicle. A little harder to defeat pollution devices on newer vehicles with all the systems run by microprocessors but if someone wants to do it they can. This law could be addressing the modified diesels that are made into coal rollers just as much as the gasoline powered vehicles with cats. You probably will still be able to buy equipment that would modify the performance of a vehicles as long as the emission equipment is not altered.
  • ToolGuy I wonder if Vin Diesel requires DEF.(Does he have issues with Sulfur in concentrations above 15ppm?)
  • ToolGuy Presented for discussion: https://xroads.virginia.edu/~Hyper2/thoreau/civil.html
  • Kevin Ford can do what it's always done. Offer buyouts to retirement age employees, and transfers to operating facilities to those who aren't retirement age. Plus, the transition to electric isn't going to be a finger snap one time event. It's going to occur over a few model years. What's a more interesting question is: Where will today's youth find jobs in the auto industry given the lower employment levels?