Should I replace Pistons rings

[tico70]

Hello

My Sidekick 92 (1.6L( JX was smoking a little bit, so I decided to check the cylinder head. Before I unmounted the head, I did a compression and a leakdown test.

these are the readings for the compression (5000 ft Altitude):

Dry:

Piston#1 : 155

Piston #2 : 155

Piston#3:155

Piston#4: 155


WET:

Piston #1 : 170

Piston #2: 170

Piston# 3: 175

Piston#4: 175

Leakdown

Piston#1 : 30% lost (hiss sound between Piston#1 and 2)
Piston#2: 10 %
Piston#3: 5%
Piston#4 10%


I removed the head ( I am going to rebuild the head), pistons shown carbon build up on top of pistons and valves.


The cylinders do not show any ridge at all. I did a quick measurement for the cylinder bore using telescopic gage

Piston#1 top: 74.95mm, Bottom: 74.97

Piston#2 Top: 74.97mm, Bottom: 74.93

Piston#3: top: 74.97mm, Bottom 74.99

Piston#4 Top: 74.96 mm, Bottom: 74.96 mm


Question: Can I replace the rings only.? If I replace the pistons rings, it will increase or improve the compression? Does it worth it?

According the bore readings, it seems that pistons are Standard (C2 marking on pistons and 2222 on block)


   

   

   

   



Thanks in advance.

[fixkick]

great compression at 5k feet

why not just put in new valve step seals, and run it.
only complaint was smoke so.?
did it smoke cold or hot, only, did it smoke only at start up or all the time, or only start up and only going down hills in gear , foot off gas pedal.?

to do rings you'd need to hone it.
new pistons do nothing, unless cracked or damaged, the rings do all sealing. (but we measure ring gape clearances too... top or bottom to edges of lands, (land to ring gaps) more are found ok, )
but valve seals are 1st.
seem to me its just those and engine has some life.. check rings on#1 yet for sticking, might be just carbon fouling there.(carbon in the top lands )??

carbon on top of pistion is running in limphome all the time rich.
a good EFI burns pure clean,. no carbon. but what you see there may be and echo of other owners running it rich in limphome.... long ago.

you only measured, cylinder taper, not out of round.? as out of round is the bad one.... rings can seal good tapered Top/down but not out or round much.
imagine a perfect circle in inside one that is not./ bingo no seal up.
we check 4 readings per cylinder to get both data. taper and out of round./

[tico70]

Fixkick,

Thanks for taking your time to respond, also thanks a lot for the really good information that you share about Suzuki's. It is a lot of hard work.

I did the measurements in a hurry. I will double check the cylinder bore again. I bought the car used aprox 12 years ago, and since then I have been doing the oil changes every 3500, same oil. It has received good maintenance, overall. The lat 2 years I didnt pay to much attention to it.

About the smoke, it is more noticeable during the cold start. the odor is stinky, lets say burnt oil. As soon the car heats up, the smoke gets reduced.


Someone can say, Why no get another car? Well I really like the simplicity of this one and also these cars are warriors.

---

I forgot to mention that I found a crack in the exhaust manifold, (piston#4)

[fixkick]

Fixkick,

Thanks for taking your time to respond, also thanks a lot for the really good information that you share about Suzuki's. It is a lot of hard work.

I did the measurements in a hurry. I will double check the cylinder bore again. I bought the car used approx 12 years ago, and since then I have been doing the oil changes every 3500, same oil. It has received good maintenance, overall. The last 2 years I didn't pay to much attention to it.

About the smoke, it is more noticeable during the cold start. the odor is stinky, lets say burnt oil. As soon the car heats up, the smoke gets reduced.
Reduces or gonE?
sounds to me like cheap valve seal fix. if car had lots of oil changes , this is it. the seals get old and hard and crack and if guides are worn here, the seal is pounded to death, and go bad, engine may only need a head job. all that is corrected, in the shop, guides, seals and all that....
The engine when a valve opens (intake) , the guides are subject to vacuum at that moment, and can suck oil down the guide, it's all about that vacuum there and some engines have no seals at all. so clearances here are important.
Many engines with head off, you push hard on side of the valve spring cap and see the stem move to the side, this is bad guides, big time.


Someone can say, Why no get another car? Well I really like the simplicity of this one and also these cars are warriors.
yes, some say better the devil you know than the unknown. cars are like that, some clean cars, (looks) are a horror inside.
I too would fix the great car. )

---

I forgot to mention that I found a crack in the exhaust manifold, (piston#4)
they all do this and gets worse and sucks air and 02 goes nuts and piston tops turn black, and EGR packs up, and MPG really bad.

yes,and your welcome and for sure in person , I might have different answer, as hands on eyes on, rule this domain.

[tico70]

I added some pictures.

[fixkick]

I added some pictures.

bad running engine ,horrid
the EFI was running rich as a pig.
must have been burning fuel like V8.
nasty mess there, the engine block is a nasty mess. and is only the victim, of EFI all messed up.
top reasons, limphome mode.
1:that exhaust crack if allows air to the 02 sensor that sensor goes to 0v, (super lean) and EFI goes super rich, and bingo.
2: and or FPR bad, and fuel pressure is at 60psi, 2 times normal (or worst both #1 and 2 are wrong)
as you can see all 4 are bad, so is not just one leaking injector, its common to all 4 cylinders this error.
you could put a new engine there and it will only repeat this calamity.
id clean that all up , and get new valve seals. then fix EFI.
that huge sludge there can (could) cause the top ring to stick, and leak,, i see the factory hone marks
is that top cylinder ridge good, run your finger nail from 1inch down the cylinder then up to feel that ridge edge? if no ridge the cylinder id bet are ok.
most are, the metal in this engine is strong (it has cylinder liners cast in place and are very strong.)
that is step one, the fingernail, test, as covered day one in all engine work classes... head off and the finger gets busy.

do not attempt to polish the metal, of the deck top of block or head,
if you do , there will be no gasket on earth that seals there. the surfaces are spec'd out for roughness and is key to head gasket seals holding


have you checked the 0.050" oil gallery orifice plug yet, front left end of head, it must be be blocked, or the cam starves from oil and seizes.

have you done the warp test per the FSM book
the steel rule test, with feeler gauges, this is covered in all books in print on engine work.
cross ruler test tells you no more than .002" warp is ok, this is like step 2 on head,
and its 2 tests, one on head, then block deck.
and if really savvy the intake side too....
overheating damage has no limits so we look and measure.
read the FSM yet, on engine chapter 6a:

the free book keeps moving here.,.. but here it is,
read chapter 6a
http://www.acksfaq.com/2016bp.php?urlnam...kerfsm.htm

note how the download button works, so keep a copy.

the classic test on warp is .001" max per foot.
lay ruler cross wise say on head bottom
using a feel the .002" dont fit. the lay it cross again from opposite corner, same dead.
repeat on the engine deck. 2 checks.
this is done on all engines head off.
if way off the head gasket blows again.



cheers ! and good luck.

[fixkick]

looks like engine run with no antifreeze for many years, (red iron oxide inside), evidence.

[fixkick]

you only said smoking a bit.
there are 4 smokes, or more, if 2 happen at once.
1: black smoke from tail pipe end end, and smell raw unburned fuel, sure and that is why the cylinders are full of carbon, as partial burned fuel makes tons of carbon.
2: white smoke that lingers a long time from end of tail pipe, this is burning oil. smells like burning oil and is.
3: same smoke from front of car at exhuast header, and is distributor o-rings bad, as all are. this is external smoke.
4: white smoke that is not smoke at all but is steam, steam is hot water, and does not linger, does not smell like oil, and is steam and antifreeze burning,
antifreeze smoke (steam) smells disgustingly sweet, a nasty sweet smell.... smells just like the liquid under rad cap off....

smoke as a word means little ,what matters is what kind of smoke,

[fixkick]

steam looks just like Tea pot smoke, it goes away in a very unique way if you watch, in no way like oil smoke.
oil smoke wants to stay around and add up.
where steam, just goes away fast.

[tico70]

I added some pictures.

bad running engine ,horrid
the EFI was running rich as a pig.
must have been burning fuel like V8.
nasty mess there, the engine block is a nasty mess. and is only the victim, of EFI all messed up.
top reasons, limphome mode.
1:that exhaust crack if allows air to the 02 sensor that sensor goes to 0v, (super lean) and EFI goes super rich, and bingo.
2: and or FPR bad, and fuel pressure is at 60psi, 2 times normal (or worst both #1 and 2 are wrong)
as you can see all 4 are bad, so is not just one leaking injector, its common to all 4 cylinders this error.
you could put a new engine there and it will only repeat this calamity.
id clean that all up , and get new valve seals. then fix EFI.
that huge sludge there can (could) cause the top ring to stick, and leak,, i see the factory hone marks
is that top cylinder ridge good, run your finger nail from 1inch down the cylinder then up to feel that ridge edge? if no ridge the cylinder id bet are ok.
most are, the metal in this engine is strong (it has cylinder liners cast in place and are very strong.)
that is step one, the fingernail, test, as covered day one in all engine work classes... head off and the finger gets busy.

do not attempt to polish the metal, of the deck top of block or head,
if you do , there will be no gasket on earth that seals there. the surfaces are spec'd out for roughness and is key to head gasket seals holding


have you checked the 0.050" oil gallery orifice plug yet, front left end of head, it must be be blocked, or the cam starves from oil and seizes.

have you done the warp test per the FSM book
the steel rule test, with feeler gauges, this is covered in all books in print on engine work.
cross ruler test tells you no more than .002" warp is ok, this is like step 2 on head,
and its 2 tests, one on head, then block deck.
and if really savvy the intake side too....
overheating damage has no limits so we look and measure.
read the FSM yet, on engine chapter 6a:

the free book keeps moving here.,.. but here it is,
read chapter 6a
http://www.acksfaq.com/2016bp.php?urlnam...kerfsm.htm

note how the download button works, so keep a copy.

the classic test on warp is .001" max per foot.
lay ruler cross wise say on head bottom
using a feel the .002" dont fit. the lay it cross again from opposite corner, same dead.
repeat on the engine deck. 2 checks.
this is done on all engines head off.
if way off the head gasket blows again.



cheers ! and good luck.

Fixkick. thanks again for all the good advice.

I am already reading chapter 6 (before removing the head).

As I mentioned, I didnt pay atention to the car in the last 2 years ( my wife was driven it).In the last months I havent used the car because I was fixing (rebuilding the transfer case). So I only started the engine a couple of times in the last 8-9 months.


I found a bad rotor, and a defective distributor cap, so probably that caused the EFI problems. The pistons carbon deposits looks bright because the oil that I added for the compression test.

   


Is that OK to use platinum bosch 4 spark plugs on these cars? I was using these ones.


The crack in the exhaust manifold is almost no noticeable. I will upload a photo as soon I can ( working out of town right now and doing these repairs during my spare weekend time)


There is not ridge at all. I did the nails test in all of them.




No. I didnt polish the block. I Used a a soft brass wire brush wheel to remove the gasket and carbon, then I used a rag with thinner to clean the surface.


Could you please point out the oil gallery orifice plug?


I always use antifreeze. 50% mixture. Could be the pretty bad tap water that I used for the mix.