Piston Slap: All Abarth That Bad Diagnosis!

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.

Help!

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.