Ford Triton Piston Slap and Oil Brand/Viscosity

[Gary Allan]

Combustion Chamber Deposit Interference. It's a soft deposit that forms on the piston that eventually has enough mass to hit the head. It's not "destructive" ..but annoying. It's IDENTICAL in symptoms..loud at cold start and retreating with warm up. Piston slap is usually a design characteristic ..not so much an acquired condition. The onset of such symptoms ..to me, anyway ..points to the aforementioned CCDI.

Given that the Triton is not noted for this "characteristic" piston slap issue, it would have me looking elsewhere for things that contour the same symptom profile.

For the sake of a $8-$10 bottle of good fuel system cleaner like Amsoil PI, it would be the first remedy of choice to eliminate one simple potential cause.

It may end up being something else like the chain tensioners or whatnot.

Combustion chamber deposit interference (CCDI) and combustion chamber deposit flaking (CCDF) are two other problems which sometimes occur in certain modern engine designs. CCDI is the result of physical contact between deposits on the piston top and cylinder head and is manifested as a loud, metallic banging sound when the engine is cold. CCDI is limited to the engines that have been designed primarily to reduce emissions, with minimal clearance—one millimeter or less—between some areas of the piston top and the cylinder head (squish areas) when the piston is at top dead center. Combustion chamber deposit flaking causes low-compression pressures to result due to improper sealing of the valves. This problem occurs when pieces of CCD flake off and end up lodged between the valve face and the valve seat. Typical symptoms of CCDF are difficulty in starting and rough running when cold.

 

[BumpDraft2004]

The thought occurs to me that a 5W is a 5W independent of whether it is a 5W-20 or 5W-30, correct? It is going to flow as a 5W when it has to on a cold morning. I thought the specs to be a 5W were a borderline pumping temperature of -30F or so. The coldest weather I have ever seen w/ the motor and the 5W-30 in question is +18F.

 

[1999nick]

Originally Posted By: BumpDraft2004
You have a point - but I bought the truck used at 33,000 miles. Now I wonder what was in it before I got it. I just looked back at my carefully kepot OC records and yes, I used 5W-30 and it happened to be PP, which, after reading some of the posting here, seems to spec out like a 0W-30. So if that is the case, then the problem was oil too THIN and not TOO thick? Yikes. I also notice that the slap (or whatever the heck it is) is REALLY bad cold and under load, like going up a hill. A freakin' death rattle.

I'd also hardly call the weather we have here cold. I am from New England and I have cranked over cars w/ dino at -15F to around -25F on a regular basis. Geez, what do 5.4 liter owners experience where I come from? It must be ready to bloody explode.

I have run Fords (4.0 liter V6 and 24-valve 3 liter V6) on the spec 5W/20 and both sounded awful on it. Drive both a combined 175,000 miles on 5W-30 and never noticed the slap.


As far as I know, Ford has never specced 5W20 oil for the German made 4.0 V-6 engine. It has always required an xxW30 oil, and has always been a rather rough and noisy engine.

 

[Jim Allen]

Did any one hear my previous comment that the problem may be due to can phasers (the VVT device)? The one time I've heard them, they sounded a bit like piston slap. I don't know enough about the problem to write a prescription, but I would advise the OP to do some research on the topic.

 

[modularv8]

I have an '06 F150 5.4l 38k miles that does the same thing. It is definately piston slap (not VCT phaser). Does it once the temperature gets below ~50F. When I first start the engine, it will rev-up for about a minute then settle down to a lower idle. During this period, the piston slap is faint and takes effort to hear it over the fan. But if I put it into gear without warm-up it is very pronounced and gets worse if I accelerate with it cold. Once I reach about the quarter mark on the coolant gauge, it is practically gone (~3 minutes). It is completely gone once the engine is warmed up. I have compared the Ford piston to cylinder clearance specs for the 5.4l engine with engines before 2004 and found that they there was a small increase in clearance for 2004 and later engines.

From all that I have read, no oil will get rid of piston slap. The only solution I have found for cold weather starts is to just start it up and let it run for about 3-4 minutes (warm-up the engine), then drive. On my truck, the piston slap is completely gone if I do this.

The piston slap sounds sort of like a mild diesel when in gear in the garage and more like a lifter (from inside the cab) when accelerating but only if I don't let it warm up on the first start of the day during very cold weather. Otherwise, the engine is as quiet as a mouse.

BTW, the differene between piston slap and VCT phaser diesel-like knocking sound is that piston slap occurs only when the engine is cold soaked and goes away when warmed up. VCT phaser sound doesn't occur when the engine is cold, but begins when the engine is warmed up.

 

[Nick R]

Our 03 4.6L doesn't have piston slap that I can tell, it runs fantastic on MC Semisyn 5W-20. IMO, Piston slap won't hurt anything. The problem comes from the fact that over the past decade auto mfr have used short skirt pistons (Very short pistons from crown to the bottom) and when cold, they can move around a little bit making some noise. (This is what my understanding of it is anyway) until the engine has warmed up and the piston expands to fill the gap.

 

[Jim Allen]

Originally Posted By: modularv8
I have an '06 F150 5.4l 38k miles that does the same thing. It is definately piston slap (not VCT phaser). Does it once the temperature gets below ~50F. When I first start the engine, it will rev-up for about a minute then settle down to a lower idle. During this period, the piston slap is faint and takes effort to hear it over the fan. But if I put it into gear without warm-up it is very pronounced and gets worse if I accelerate with it cold. Once I reach about the quarter mark on the coolant gauge, it is practically gone (~3 minutes). It is completely gone once the engine is warmed up. I have compared the Ford piston to cylinder clearance specs for the 5.4l engine with engines before 2004 and found that they there was a small increase in clearance for 2004 and later engines.

From all that I have read, no oil will get rid of piston slap. The only solution I have found for cold weather starts is to just start it up and let it run for about 3-4 minutes (warm-up the engine), then drive. On my truck, the piston slap is completely gone if I do this.

The piston slap sounds sort of like a mild diesel when in gear in the garage and more like a lifter (from inside the cab) when accelerating but only if I don't let it warm up on the first start of the day during very cold weather. Otherwise, the engine is as quiet as a mouse.

BTW, the differene between piston slap and VCT phaser diesel-like knocking sound is that piston slap occurs only when the engine is cold soaked and goes away when warmed up. VCT phaser sound doesn't occur when the engine is cold, but begins when the engine is warmed up.


Great summation, thanks. I must be lucky. My '05 (21K miles) is whisper quiet, even with a 10F start.

 

[CROWNVIC4LIFE]

Originally Posted By: rudolphna
Our 03 4.6L doesn't have piston slap .


All our 4.6 engines have piston slap even in Miami jungle heat...My 99 4.6 even had it...All cars use 5w20 Motorcraft...Even the 99 used 5w20 Motorcraft...It did the same thing on Castrol oil...Filters make no difference...I use Motorcraft filters but it was the same thing on any filter.

It does not do it everyday and its only for a very short period and once its warmed up its gone.

 

[tig1]

Originally Posted By: CROWNVIC4LIFE
Originally Posted By: rudolphna
Our 03 4.6L doesn't have piston slap .


All our 4.6 engines have piston slap even in Miami jungle heat...My 99 4.6 even had it...All cars use 5w20 Motorcraft...Even the 99 used 5w20 Motorcraft...It did the same thing on Castrol oil...Filters make no difference...I use Motorcraft filters but it was the same thing on any filter.

It does not do it everyday and its only for a very short period and once its warmed up its gone.


My 96 Merc GM 4.6 never had PS. In 218,000 miles the engine always started with no unusual noise. No doubt that engine had tons of miles left in it.

 

[demarpaint]

Originally Posted By: aquariuscsm
I keep reading about brand new cars having piston slap. I totally agree with John Browning,piston slap is a production defect and nothing costing tens of thousands of dollars should be mediocre,it should be flawless. If I bought a brand new off the showroom car and it had piston slap,it be delivered right back where it came from in a heartbeat.


+1

Harmless or not if I bought something new that had piston slap, or any odd noise for that matter they'd be fixing it. Older engine I'd live with it. JMO

 

[440Magnum]

Originally Posted By: Gary Allan
Are we sure this isn't CCDI? The symptoms are identical.


In this case, no. I was just addressing the fallacy about piston slap being harmful. The truth is closer to, "the manufacturers did friction-increasing engine-life reducing things to HIDE piston slap for 40 years and now they don't anymore."

When I built the 440 for my '66 Polara a few years ago, the combination of piston and clearance choices I made wound up giving it an incredible amount of piston slap- sounds like a 7.3L Powerstroke when its cold. 20,000 miles and the behavior hasn't changed AT ALL, and UOAs are normal. Were I doing the same engine now, I'd make the same choices EXCEPT coated-skirt pistons are now commonplace and that would drastically reduce the noise.

 

[440Magnum]

Originally Posted By: 440Magnum

When I built the 440 for my '66 Polara a few years ago, the combination of piston and clearance choices I made wound up giving it an incredible amount of piston slap- sounds like a 7.3L Powerstroke when its cold.


I should add that when I first started that engine and heard the piston slap, I actually disassembled it again and went through all the clearances with the machine shop... it is IN SPEC. Just the nature of those pistons (centered pin, short skirt, no coating) in that engine.

 

[BumpDraft2004]

Thanks everyone....

 

[steve20]

and keep on using that 5-30 (seriously)




Steve