Technical Compression Test

[jrkitching]

they are quoting $11K, yikes

!!

Ouch! I can feel your pain all the way across the Atlantic Ocean.

just curoius, can you even get a boroscope down to the cylinder wall without removing the head and multiair section

I'd have thought you'd just take out the plugs and go in that way.

Just want to hear yall thoughts

Firstly, condolences - this is not a nice place to be. Your car is the worst possible age for this to happen. Any newer, and you'd have a warranty claim; much older, and you'd just scrap it.

You've been unlucky; this sort of problem doesn't happen often (thankfully).

I don't know how the garage repair scene works in the USA, but in Europe, most folks would be looking at a secondhand engine at this point, either to swap complete or to salvage the bottom end from. Availability is so good, one chap here who regularly fixes crashed cars gave one away for free. Folks handy with spanners could buy a wreck, take what they need, then sell what's left on ebay and show a good profit.

An alternative is to have it repaired by a specialist engine rebuilder, but finding someone local to you might be problematic; I'd expect most shops in your neck of the woods would be more familiar with big block V8's than engines which are more like an Italian designed sewing machine; you need to work to much finer tolerances to rebuild these properly.

 

[varesecrazy]

Sorry to hear that..
The one silver lining here: you know what is wrong and not to spend out unnecessarily

A wrecked 500 will still be cheaper than $11,000

And you could potentially part out the rest

Biggest issue could be getting help to swap motors..
BUT .. really that is 'just nuts and bolts'

Do feel free to keep on asking

 

[portland_bill]

Scoring on the cylinder walls can be caused by,
debris ingress -unlikely unless it has been run without an air filter
Bits of spark plug or valve breaking off. You've not reported any such failure, so this also unlikely.
Broken piston ring. This is most likely, as if it then escapes upwards it will damage the bore and may take a bit of piston with it, and can then bounce around on top before eventually ejecting into the exhaust. It will probably not pass through the catalyst, so if repaired, that needs taking off and shaking to remove the bits, if only to prevent annoying rattles later.

A broken ring can be caused by a manufacturing defect. With such a low mileage, this could be so, as a faulty ring will not last long. However, for Fiat to give anything as goodwill, you'd have to have a full dealer service history, and then pay the full repair cost before they'd contribute. Overall, you can fix this cheaper elsewhere.
Broken rings can also be a result of overheating. Has it ever suffered overheating, at any time in the past? Such damage can occur some time before resultant component failure.

Boroscope will have been put down the spark plug hole. Interesting if you know what the inside should look like, just a confusing close-up if you've never seen inside before, but good for them to have done this.

Misfire will occur at lower revs, due to the compression loss. At higher revs, with only part of one ring broken, there is less time for compression pressure to be lost, so it runs better.

As said above, look around for a good used engine, and get a smaller, local, and trusted garage, to swap it over for you. With such a small car in America, I'd expect a few to get squashed, so able to liberate a good engine. And don't pay too much for the engine, there is after all a very limited market for them used.

 

[Pugglt Auld Jock]

Only fly in the ointment I can think of is American labour costs. My perception, having spent time over there with my sister and daughter at various times, is that you can DIY very cheaply. There is wonderful availability of just about anything you might want and very cheap too if you shop around. However, call a tradesman in and the cost goes through (thru) the roof?

 

[varesecrazy]

Misfire will occur at lower revs, due to the compression loss. At higher revs, with only part of one ring broken, there is less time for compression pressure to be lost, so it runs better.

As said above, look around for a good used engine, and get a smaller, local, and trusted garage, to swap it over for you. With such a small car in America, I'd expect a few to get squashed, so able to liberate a good engine. And don't pay too much for the engine, there is after all a very limited market for them used.

That was my thoughts on the misfire..
Basically how diesels 'get going'


U.S. market can be weird

I used to be on a US forum for niche Italian motorcycles

They cost the same new in USD as we payed in UK pounds.. so HALF.PRICE..!!

As you say 'rarity' can work both ways..

$11,000 is a lot of money.. but it is A BRAND NEW MOTOR

years ago I bought a FIAT that developed a fault..
A 'short engine' ( essentially replacing the parts you also need) was DOUBLE the purchase price of this good low mile .. recent model FIAT

 

[iwannafish]

Misfire will occur at lower revs, due to the compression loss. At higher revs, with only part of one ring broken, there is less time for compression pressure to be lost, so it runs better.

one more question, under this condition with the scoring on the cylinder wall, would just a piston and ring replacement be feasible or I have to fix the scoring on the cylinder wall also...

will the scoring on the wall damage the new piston

 

[iwannafish]

thanks everyone for ur advice

I'm really hoping I can save this car is cause I get 42 miles per gallon with it...I love it...my jeep is like 18 miles per gallon

Here are my options:

1) pay dealership $11K, not even a consideration since dont have that $$$ to spend

2) new engine - $3500 and find local mechanic to install...my mechanic wont touch these cars

3) used engine - $1500 to $2000 very few available and has about 45K miles

4) replace piston and ring if dont have to fix the scoring on the cylinder wall

actually, another reason I want to keep this car is after reading your comments and correlating them to youtube videos I feel like I can fix this myself...I can definitely replace the multiair unit now vs having no clue what it was 5 months ago...

 

[Pugglt Auld Jock]

Scoring of any sort is not good but if it's only light you'd probably get away with honing it and fitting a new piston and rings. I've done this in the past on "town runabouts" we've owned and it's been fine. For a vehicle which will be doing high mileage running at speed on the open highway I'd be a bit more unsure.
Whatever you end up doing, I wish you good luck.

 

[portland_bill]

one more question, under this condition with the scoring on the cylinder wall, would just a piston and ring replacement be feasible or I have to fix the scoring on the cylinder wall also...

will the scoring on the wall damage the new piston

As Jock says, scoring of the bore is not good, but will depend on how deep.

Light scoring might respond to honing (using abrasive stones to resurface the bores), but this can only really be done with very light scoring. The slightly larger bore may result in lower compression, but will be close enough to work ok. I'd only be doing this to an old engine, in an old car, that was near the end of its life anyway. New rings on a damaged bore can often pick up and fail again, usually worse the second time.

Deeper scoring may be fixed with a rebore, but that means all four need boring to the same size, so four new pistons. This is limited to the oversize pistons available, and if the deepest score is less than the largest piston. Often this can only be determined by reboring in stages until the score disappears, as measuring its depth is difficult. The machine shop would have to know what pistons were available, then bore the engine in stages. If successful, then fit the new pistons of the appropriate size. A lot of work, and a cost even if unsuccessful. There will also be the cost of removing and refitting the engine, dismantling, gaskets, etc.

A replacement used engine, will only cost the remove/refit, plus fluids. This is the path I'd recommend. Find a used engine via a source you can trust, maybe with a guarantee.

If mine, and I had alternative transport, I may well dismantle the engine to inspect closely, as time is my own, so no labour costs. For most people, they have to pay labour costs, so the engine dismantle bit is very expensive. If it's not expensive, don't trust the workmanship. A remove/refit is simpler, and lower risk.
(Been watching some YouTube vids about a broken engine in the US. I was very disappointed with the lack of expertise at the workshop, and also at the machine shop. Neither inspired me with confidence, appearing to be only slightly better than the amateur owner.)

 

[Pugglt Auld Jock]

As Jock says, scoring of the bore is not good, but will depend on how deep.

Light scoring might respond to honing (using abrasive stones to resurface the bores), but this can only really be done with very light scoring. The slightly larger bore may result in lower compression, but will be close enough to work ok. I'd only be doing this to an old engine, in an old car, that was near the end of its life anyway. New rings on a damaged bore can often pick up and fail again, usually worse the second time.

Deeper scoring may be fixed with a rebore, but that means all four need boring to the same size, so four new pistons. This is limited to the oversize pistons available, and if the deepest score is less than the largest piston. Often this can only be determined by reboring in stages until the score disappears, as measuring its depth is difficult. The machine shop would have to know what pistons were available, then bore the engine in stages. If successful, then fit the new pistons of the appropriate size. A lot of work, and a cost even if unsuccessful. There will also be the cost of removing and refitting the engine, dismantling, gaskets, etc.

A replacement used engine, will only cost the remove/refit, plus fluids. This is the path I'd recommend. Find a used engine via a source you can trust, maybe with a guarantee.

If mine, and I had alternative transport, I may well dismantle the engine to inspect closely, as time is my own, so no labour costs. For most people, they have to pay labour costs, so the engine dismantle bit is very expensive. If it's not expensive, don't trust the workmanship. A remove/refit is simpler, and lower risk.
(Been watching some YouTube vids about a broken engine in the US. I was very disappointed with the lack of expertise at the workshop, and also at the machine shop. Neither inspired me with confidence, appearing to be only slightly better than the amateur owner.)

Great post PB. All so true. It has to be remembered that the depth of a score in one side of the bore means enlarging the bore by the same amount on the other side when the boring bar actually cuts the new size. I don't try to guess this myself I stick the block (or barrel if it's a bike) in the car's boot and pop down to the engineering works (usually Browns in Leith:https://georgebrown.co.uk/ although it's been a few years now since I did the last one.) I let them tell me if the job's a "goer" and what they want me to source. ALWAYS check and source new pistons and rings before starting work and actually get your "sticky mitts" on them in the flesh. Of course, you can dramatically overbore the engine and then install sleeves to get back down to a desired size but you're only going to do that if the engine is a rare one - or you've got deep pockets! Same advice on crankshaft regrinds by the way, don't grind until you know you can actually get the shells!

Having rebuilt a number of engines in my own garage over the years I can't stress how important cleanliness is. You've got to have almost clinical levels of cleanliness on your work surfaces and all the parts must be properly cleaned. I farm this out to a local electric motor rebuilder who has a hot chemical bath for cleaning his parts (he does some really big electric motors from factories). He puts my parts in to make up the load and so doesn't do a "run" just for me alone. The cost is peanuts but I have to wait until there's a whole load to be done. I might consider trying to manually clean some 'bike or lawnmower engine parts but a car engine is better done in the bath. Then, when I've got it back I wash through all the oil galleries and blow out with compressed air.

As you say, I'd be tempted to dismantle and inspect it myself because no cost to me. But in this instance I think your suggestion of obtaining a used engine, Of proven acceptable mileage and with warranty. I think, unless you are buying a really cheap unit, and I wouldn't recommend that for obvious reasons, that it's entirely reasonable to expect it to be guaranteed, would be my recommendation too. Even this will not be a "cheap" exercise though as there will be a whole host of ancillaries to be swapped from the old unit (varies form supplier to supplier).

 

[jrkitching]

ALWAYS check and source new pistons and rings before starting work

:yeahthat:

A good engineering shop will want the pistons & rods before starting work - they'll machine the bores to suit, and if they're really good, they'll balance them as well.

This is what the best shops will do. And whilst this link refers to aircraft engine overhaul, it's actually more important with a car engine, because the rotational speed is much higher.

I'm really hoping I can save this car is cause I get 42 miles per gallon with it...I love it...my jeep is like 18 miles per gallon

Eleven thousand dollars buys a lot of gas - especially in the USA .

 

[iwannafish]

:yeahthat:

Eleven thousand dollars buys a lot of gas - especially in the USA .

How true


With limited resources around here and urs advice, will take my time to look for a good used engine...thanks again and stay safe!!!!

 

[portland_bill]

Please update the thread when there's any progress. Whilst we can't help from the UK, we do feel for you, and would appreciate knowing the end of the story. Thanks