slight nocking soumd at acceleration....
Former ******
Joined: Nov 2004
Posts: 4,901
Likes: 2
From: Salt Lake City, Utah
To decarbon, find a suitable vacuum line, and use a product like Seafoam, B-12, or BG-44K. I don't know if an of those brand names are found in Europe, but there should be similar products. It can't hurt and it could stand to improve things. You have an assistant try to maintain 2000 RPM while you add about 30% of the contents of the can. The engine may start to chug, and there will be lots of whie smoke. Then let it sit for between 5 - 30 minutes to let the solevents break down the carbon, then restart. Drive it till the smoke is gone. Changes are you will have slightly more power, smoother operation and throttle responce, and who knows, the ticking may be gone.
Last edited by khantyranitar; Nov 15, 2006 at 08:44 AM.
Postmaster
Joined: Apr 2001
Posts: 3,818
Likes: 3
Originally Posted by Pablo-UA
why noise dissapeares when the engine is hot? and 20 minutes ago I draw to the market.... the engine was not warmed up... but no noise... nocks in the morning only
Elder User
Joined: Apr 2005
Posts: 882
Likes: 0
From: Wichita
Sounds like bearings to me. Especially if it goes away when it warms up - metal expansion.
How deep is the sound? Low frequency or more like a tick? I thought maybe piston slap. The sound is between a tick and a knock.
How deep is the sound? Low frequency or more like a tick? I thought maybe piston slap. The sound is between a tick and a knock.
Posting Guru
Joined: Oct 2006
Posts: 1,175
Likes: 0
From: charlotte nc
alot of the time you can stop it by going to a higher octane gas, reason is that most high milage engines have deposits that INCREASE the compression, This will cause a lifter rattle during acceleration. Try some high test and if this helps you may adjust the timming and then go back to regular gas.
Thread Starter
|
Post Fiend
Joined: Oct 2005
Posts: 5,242
Likes: 0
From: Kiev, Ukraine
The sound is like a tick. And what is the most interesting I cant find where is the sourse. Somwhere from under the hood, but there is no sound without the load. I tried to use ocrtane 93 gas.... No difference. ANd today it was no sound.
Former ******
Joined: Nov 2004
Posts: 4,901
Likes: 2
From: Salt Lake City, Utah
Originally Posted by thefarelaneman
alot of the time you can stop it by going to a higher octane gas, reason is that most high milage engines have deposits that INCREASE the compression, This will cause a lifter rattle during acceleration. Try some high test and if this helps you may adjust the timming and then go back to regular gas.
Freshman User
Joined: Jul 2004
Posts: 38
Likes: 0
From: The Prairies in Canada
sounds like either wrist pins or worn pistons causing piston slap, more than likely piston slap. when the piston heats up it will expand causing it to be tighter in the bore, and the noise goes away.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
Thread Starter
|
Post Fiend
Joined: Oct 2005
Posts: 5,242
Likes: 0
From: Kiev, Ukraine
Mercedes use forgered light pistons for V6, V8 and V12 engines.... And they have steel part for better heat distribution. Truly, these pistons are made by Kolben Schmitd ore Mahli... Mercedes does not make pistons. KS ore M just add MB labet to these pistons....
Post Fiend
Joined: Apr 2005
Posts: 5,720
Likes: 5
From: Washington state
Pablo,
how much piston/cyl. wall clearance (bore)?
3.0L spec with standard high eutetic cast alum pistons
Piston-to-Bore Clearance 0.030-0.056mm
Service Limit 0.081mm Max.
factory pistons are high heat expansion rate special alum alloy cast for quiet engine operation and low oil consumption with tight bore fit....
most forged pistons are a low expansion rate because of alloy restrictions....great for racing extra high rpm toughness but can be noisy and higher oil consumption along with faster ring and cylinder wear because of higher ring pressures required to seal high compression
those Mahle cast pistons are probably made for an alum. block Mercedes with totally different thermal expansion characteristics
extra clearance tolerance at cold low rpm operation=more noise especially until oil fills gap and supplies hydralic load shock support....piston/bore gap decreases as piston expands...
try a 0w40 winter or 15w40 in summer ester oil such as Motul....clings to metal cyl walls
or switch to a teflon panel shirt piston if Mahle makes one in cast
what's your max rpm now on that racing 3.0L Ford aka 3.4L Ford/Mercedes hybrid?
how much piston/cyl. wall clearance (bore)?
3.0L spec with standard high eutetic cast alum pistons
Piston-to-Bore Clearance 0.030-0.056mm
Service Limit 0.081mm Max.
factory pistons are high heat expansion rate special alum alloy cast for quiet engine operation and low oil consumption with tight bore fit....
most forged pistons are a low expansion rate because of alloy restrictions....great for racing extra high rpm toughness but can be noisy and higher oil consumption along with faster ring and cylinder wear because of higher ring pressures required to seal high compression
those Mahle cast pistons are probably made for an alum. block Mercedes with totally different thermal expansion characteristics
extra clearance tolerance at cold low rpm operation=more noise especially until oil fills gap and supplies hydralic load shock support....piston/bore gap decreases as piston expands...
try a 0w40 winter or 15w40 in summer ester oil such as Motul....clings to metal cyl walls
or switch to a teflon panel shirt piston if Mahle makes one in cast
what's your max rpm now on that racing 3.0L Ford aka 3.4L Ford/Mercedes hybrid?
Thread Starter
|
Post Fiend
Joined: Oct 2005
Posts: 5,242
Likes: 0
From: Kiev, Ukraine
No it is not piston to bore nock. Sounds different.
It seems to me this is noise of piston pin. well.... fortunatly I have a box with 4 pistons kit.... but I'm not sure... The other hypotesa - - #4cranckshaft bearing. Well... if the noise will increase, I gonna replace bearings in December (crankshaft is expencive and difficult to replace).
Yeah! 96_4 WDR is right, my engine is more noisy then original...
To have more RPM I use custom camshaft (may be it nocks...???), but.... the first, that happend when I tried to rev it up to 7000 RPM - strange nocking noise... When I removed pass. side valve cover I saw that one valve keeper dissapeared (later found in oil pan). I had to use dual valve springs of Tavria. But hight RPM kills the tranny....
It seems to me this is noise of piston pin. well.... fortunatly I have a box with 4 pistons kit.... but I'm not sure... The other hypotesa - - #4cranckshaft bearing. Well... if the noise will increase, I gonna replace bearings in December (crankshaft is expencive and difficult to replace).
Yeah! 96_4 WDR is right, my engine is more noisy then original...
To have more RPM I use custom camshaft (may be it nocks...???), but.... the first, that happend when I tried to rev it up to 7000 RPM - strange nocking noise... When I removed pass. side valve cover I saw that one valve keeper dissapeared (later found in oil pan). I had to use dual valve springs of Tavria. But hight RPM kills the tranny....
Lead Driver
Joined: Sep 2003
Posts: 7,015
Likes: 208
From: SoCal
Pablo,
It sounds like you may have cobbled together some parts that don't fit together properly.
96_4wd,
What you said about forged pistons mostly made sense, but your initial assertion is not correct. Everything I read about forged pistons says that they are more dense than cast pistons, so they tend expand more with temperature. As such, they are usually fitted more loosely in the cylinder (more clearance) so they won't bind up when they warm up. That's the problem with the 5.0 engine in my 87 Mustang, and combined with low tension piston rings to reduce friction, its oil consumption rate is among the highest of modern engines. This is why Ford went to hypereutectic cast pistons in the more recent engines; they are dimensionally more stable with temperature, so they can be made to fit more precisely in the cylinder even when cold.
It sounds like you may have cobbled together some parts that don't fit together properly.
96_4wd,
What you said about forged pistons mostly made sense, but your initial assertion is not correct. Everything I read about forged pistons says that they are more dense than cast pistons, so they tend expand more with temperature. As such, they are usually fitted more loosely in the cylinder (more clearance) so they won't bind up when they warm up. That's the problem with the 5.0 engine in my 87 Mustang, and combined with low tension piston rings to reduce friction, its oil consumption rate is among the highest of modern engines. This is why Ford went to hypereutectic cast pistons in the more recent engines; they are dimensionally more stable with temperature, so they can be made to fit more precisely in the cylinder even when cold.