I changed oil 3 months ago (Selenia K). What was in engine when I bought car, that was total ****. So I changed oil as 1st thing. But after that original dealer solved valve clearance and they found a lot of sludge under valve cover. So they cleaned it. I think that during this mechanical cleaning a lot of sludge dropped down to oil pan. Thats why I decided to change oil once again. I dont know how piston slap originate - what is real cause of piston slap effect? Running on old oil? Or engine overheating? Because in valve cover was oil sludge, I think it should be combination of old oil + crazy driving... Im also not sure if changing oil can stop piston slap sound - I'm afraid it doesn't .

Rado77 said:

... Im also not sure if changing oil can stop piston slap sound - I'm afraid it doesn't .

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it will probably not ... In the past, Wynn's was well renowned to cure various noises in engines, so once you've drained your sump of all crap (flushing with gasoil is one of the options), fill with good grade oil, add the Wynn's (or Bardhal or else) and see if it was worth it. Shouldn't make it any whorse ...

BRs, Bernie

Is it Wynn's Super Charge?

Rado77 said:

Is it Wynn's Super Charge?

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Yes, that was the name, and here's what they claim ...

Regarding piston slap, it happens when the cylinder/piston starts to get worn: when the piston is risen in the cylinder by the rod (compression stroke) it's skirt (bottom) is pushed against the cylinder front wall; then the ignition is done and during the power stroke the piston's skirt is pushed against the back wall. This is normal and is due to the angle that the rod makes with the cylinder axis.

During that tilt, if the gap is too big, one can hear a typical metallic/ticking sound which could very well be happening at one cylinder only ...

Sometimes, engine manufacturer try to compensate a bit by shifting the piston/rod connection a bit toward the front (or the back, can't remember or figure out)

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

Thanx for info Bernie ! ;-) But....if I plan to reclaim, I need this sound to be heard. Because additive products can help only for a while, and I think (if it really stop that sound), it will come back after month of car usage. Maybe yes, maybe not - I have no experiences...But if they refuse my reclaim, I can use this additive then.
So this weekend - I'll check rod knocks with screwdriver method. And next weekend I'll change oil (because in current oil is also some "booster" additive - by mechanic's words the best product they ever had...and oil level is 2mm over MAX on dipstick)

So overal - previous owner caused piston slap (+ oil sludge on top) by engine overheating (most probably because of running on old oil, or low oil level). He masked that sound by using some thick 10W oil, maybe with some additive or something....That's why I didn't hear anything during cold test drive. Once I changed oil to original Selenia K 5W-40 , ticking was there (on hot engine) + that "plastic" sound from one cylinder (piston rod bearing?).

Update: I disconnected spark plugs on iddle - engine sound was the same for all 4 cylinders. So compression looks good. Measured injectors - all 16ohms. Tried screwdriver method to determine rod knock - no screwdriver movement down, no sound.

Next weekend - using flush additive (15 min iddle), drain old oil, and add new original Selenia K oil + Bosch filter + Wynns Super Charge additive. I'll try to have oil directly in the middle between min and max

PS

Rado77 said:

I changed oil 3 months ago (Selenia K). What was in engine when I bought car, that was total ****. So I changed oil as 1st thing. But after that original dealer solved valve clearance and they found a lot of sludge under valve cover. So they cleaned it. I think that during this mechanical cleaning a lot of sludge dropped down to oil pan. Thats why I decided to change oil once again. I dont know how piston slap originate - what is real cause of piston slap effect? Running on old oil? Or engine overheating? Because in valve cover was oil sludge, I think it should be combination of old oil + crazy driving... Im also not sure if changing oil can stop piston slap sound - I'm afraid it doesn't .

Click to expand...

I've been reading this thread with great interest and as it's gone on, slowly, as is often the case, more and more interesting information is "leaking" through. Rado77 is describing a number of symptoms - noises, very dirty engine oil, sludge build up and more. Now there is talk of "magic potions" to cure the problem.

I'd love to be able to actually stand beside the car and hear these noises myself but as that's not possible I think the most likely scenario is that this poor car has been grossly abused by it's previous owner/s. It sounds as if it's oil change intervals have been ignored and therefore, by implication, it's likely that other maintenance has also been ignored. You might very well quieten it down temporarily with a treacley thick oil additive like the one you mention but I doubt if it will be a long term solution.

If the sludge situation in the rest of the engine is as bad as you tell us it was in the cam cover then I would be nervous about doing a full engine flush. There are many instances of dirt being set free inside engines which have had this done which subsequently ended up restricting or totally blocking up oil ways and causing even more damage by starving bearings of oil.

Of course it's very difficult, sitting here on my couch, to be sure about any of this. But, if the noises do turn out to be down to the likes of piston slap, wear in valve gear, etc - in other words due to wear in several components - I think it very likely you're going to have to strip the engine to properly sort it out as it's likely other parts, which may not be making their problems known at this time, will also be damaged.

I hope most sincerely that I'm wrong Rado. Please do continue to update us - every time I come to the Forum I always look at this thread.

Best of luck
Jock

PS. You can have excellent compression figures and piston slap at the same time. It's how well the rings seal that give you the compression and excess clearance between piston and cylinder wall that gives "slap"

Hi Jock. I'm happy that someone read my post With this car I learned a lot new information about engines. I didn't know what is rod knock or piston slap, and piston is covered by some teflon material on sides...I had never problem with cars (except wrong spark plug and so on...small issues, I changed oils, filters, brakes, fixed ehausts and so on. But I never had some general issue like this).
What I did today - I lowered engine oil level directly between min and max. You are right about engine flush, I don't do it. It's dangerous and I can damage more than repair.
And regarding pistom slap (that was also tip by mechanics in oficial FIAT service) - it's strange that there is no piston slap when engine is cold! By my logic - piston slap should be louder on cold engine, when piston is "smaller" and lubrication is poor...

Rado77 said:

it's strange that there is no piston slap when engine is cold! By my logic - piston slap should be louder on cold engine, when piston is "smaller" and lubrication is poor...

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You're right, you would expect piston slap to be worst when cold. So you've got some strange unexplained things going on here!

Yes my '77 A112 Abarth 70HP sounded like a diesel from new, when started in the winter time.
Unfortunately it's long gone due to rust.

1. So, valve clearances are still wrong (+0,05 mm, "gap" too high) and ignored?
2. Filters are cheap, try to swap the oil filter first (filter only), to "see" (hear) if there will be any change (in engine sound, related to oil flow/pressure). It may be too late for such "test".

PS
Changes in the engine (tolerances, fittings, clearances - whatever you call it) VS Temperature, are NOT always linear (as temp. rises - clearance goes only one way, "down" - nope). Example, textbook graph (OK, it wasn't Fiat, but it can be similar or worst - that's why noises are "unexplained").

Rado77 said:

I don't know Fiat's engine sounds.

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Maybe your expectations are too high. This is not luxury car. All Fiats were/are "noisy" to some extent.

And what causes ticking noise, if the ticking goes from camshaft area? Is it because of contact of camshaft lobe with shimm surface? That is causing ticking - when distance between cam lobe and shimm is too big? Or is it valve-related - for example when that valve is closing?
I'm thinking....if...in my case is valve clearance the same on all shimms...then....I should hear ticking from each shimm right? But by frequency of ticking it looks that only one shimm/or valve is ticking and others are ok...strange...
And now - if I decarbonize in and ex valves by something...will valve clearances change?

Answer to your questions was probably in the numbers I asked for, and it was ignored.
Clearances and shim sizes, before and after adjustment.
Now, there is no way to tell. Diagnostic information is lost forever.
Look at the Guide, one valve (for example exhaust) can be way off (comparing to other 3), and that one will be more noisy/noisier. If there is a wear in the engine, sure it can be uneven, unequal between cylinders, valves, etc. No surprise here (it should be obvious).

Valve train noise is caused by three things, roughly speaking:
- clearances (but all of them, not only shim-to-lobe adjustable "gap") + wear,
- valve speeds/acceleration (depends on camshaft lobes geometrical shape/profile and its wear),
- stiffness (in general - in mechanical engineering, everything is a spring and will flex/twist).
In practice, "engine sound" is a combination between design (Fiats are a bit "noisy by design") and wear (natural + poor maintenance).

So one valve (with most wear) can literally crash into seat and/or bounce back, making noise.
And yes, if there's some kind of residue (carbon) on the valves/seats, and you'll remove it, clearance will change too (one of the reasons why valve adjustment can be multi-stage process - like once is not enough, you adjust it, and it still "ticks" - that's "normal", kind of).

Once again, suggested plan (rule out/fix one at the time):
- valve clearances, including carbon residue (possibly) messing up measurements/adjustments,
- lubrication and filtration (oil flow) issues, where filter is as (or more) important as oil (type, condition),
- VVT,
- timing,
- others (ignition, entire fuel system including evaporation/fumes, sensors, crankshaft/pistons).

One strange info - I had enhibe on 10 mknutes on hot idle, ticking was there. But - ticking was gone for 15-20 seconds! And after that ticking came back... Abyway car is still starting & running well, also dynamics on higher rpms is good (and for 77HP surprisingly good).
The problem is that I live in skyscraper without garage :-( Hard to do things on street :-(

Was the AC ON?

It's not piston slap, .... if it is it will get much worse soon and you won't have to worry about it.

I'm sure it's VVT related from all the junk oil.

Noise won't necessarily come from the cam gear ... think about BMW VANOS (that makes noise in higher RPM... doesn't mean fiat won't rattle at idle rpm)

Use engine flush. I have for a few times... 3 times to current car (220k km now) and 4-5 times in the previous (previous owners didn't change the oil frequently enough).
It won't hurt anything... it's not as powerful as you might hope.... the cleaning agents are 99% kerosene and turpentine.
Modern oil has stronger cleaning agents in it.

Hi Aurick ,

AC was OFF all the time. I also think that it's not piston slap - it's not "metallic" ticking and also not too noisy as "classic" piston slaps whose I can hear on YouTube.
Regarding VVT - I know VVT system from Renault - I completely dismounted variator there and understood how it works. On FIAT I think that variator is similar - it has locking pin with small spring. I think at idle is variator locked in zero position with that pin, and it opens only when accelerator pedal is pressed. So I think VVT isn't working on idle and variator is locked...I also checked VVT position value through MES and on idle it shows zero degrees of camshaft timing. And variator is also running ok - because if not, ECU will imediately find difference between crankshaft and camshaft position signal and light on engine MIL.

-> I can imagine only one thing - by some reason has locking pin ripped edge, and variator is not fixed on it's zero position, and is constantly fighting with oil pressure like (open/close/open/close...), and that causes ticking. But - in my case, ticking is not there when engine is cold ! It rises as temperature rises too. For example during winter - if engine was on operational temp and I opened hood, ticking has gone after few minutes. So it's directly dependent on engine temperature !!!

New oil + BOSCH filer is on the way - so this weekend I'll change it again.

And one thing - may I take out electromagnetic valve without taking out whole valve cover? I see that there's only one torx screw ...I'd like to check that valve, if guy in service cleaned it properly..

Another tip guys - as you can see on photos, I have missing bolt on intake manifold (including metal ring inside). I'm sure that upper is missing, another below I have to check if is there or not. Maybe it sucks air to 4th cylinder there and that's why engine sounds like "plastic" under load and I hear also ticking on hot (when distance betwwen cylinder head and intake manifold changes a little bit). WHAT DO YOU THINK???

aurick86 said:

It won't hurt anything... it's not as powerful as you might hope.... the cleaning agents are 99% kerosene and turpentine.

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NOT true. Most such products are based on "white spirit" (MINERAL turpentine) type solvent.
Almost never "kerosene" (like "lamp oil" - it will hurt NBR rubber), but cleaner, finer fractions (same or similar to aviation jet fuel or special diesel).
Study engine flush ingredients, chemicals codes: https://echa.europa.eu/en/information-on-chemicals, check "Trade names" section.
Homework: check 3 different brands, for example - Bardahl, Wynn's, LiquiMoly. And report back (what's the main ingredient).

aurick86 said:

Modern oil has stronger cleaning agents in it.

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Therefore using "engine flush" is a waste of time and money. Don't do it folks.

Rado77 said:

And one thing - may I take out electromagnetic valve without taking out whole valve cover? I see that there's only one torx screw ...I'd like to check that valve, if guy in service cleaned it properly..

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Have you ever seen a valve adjustment Guide here?
If you are so "experienced" with VVTs in other cars, why are you afraid to pop one bolt?
Yes, you can take it out.

And most important question: when will you adjust the valves properly?
When this topic grows to 10 or 15 pages?
Oil channels/galleries in the cover might be clogged, spoiling VVT operation.
It requires mechanical cleaning (no "engine flush" BullShiiiieeet will help).
Valve adjustment is a great "excuse" to pop the cover and clean it well. You can do it at parking lot (no garage needed).

1st I have to check that intake manifold. Questions like "who did and what with intake system on car 5 years old?" , "is there broken bolt in cylinder head?". "Who did what that also metal ring is missing from intake manifold?" Its not easy to take it from it's hole...and "what is status of intake gaskets if someone did something with intake manifold?"
So I have to check it as first, because small vacuum leak can be real root cause of my issues:
- "plastic" noise from one cylinder during engine load
- one valve ticking sound (on hot)
- small shaking with car shasis and steering wheel on hot idle
- MES report of higher voltage by knock sensor for 4th cylinder

All this can be caused by 1 missing bolt. We will see after weekend

Intake manifold's gaskets checked, added 2 missing bolts. Checked electromagnetic valve. I had no time to test it...