tick of death in 2.5 2003 outback

[Boddi]

Hi all,

thanks for all here, now i am figure out how i cat get the tick of death from my 2.5 2003 outback. This tick is just when the engine is warming up and after that it go. is this tick coming from the valve or is it coming from the piston.........

[Scoobaroo]

Hi all,

thanks for all here, now i am figure out how i cat get the tick of death from my 2.5 2003 outback. This tick is just when the engine is warming up and after that it go. is this tick coming from the valve or is it coming from the piston.........

 

Sounds like piston slap.

Get used to it, my friend. Once it starts, it's there to stay.

In my experience, trying different brands of expensive synthetic oil will only drain your wallet.

 

Our '02 OB gets the cheapest store brand SL/SM rated dino oil that I can find.

Mobile 1 5w30 made it sound like a piston skirt was ready to hammer through the cylinder wall.

 

Cheap-azz dino oil = (almost) quiet at cold start.

Expensive, hyped-up synthetics= unspeakably loud engine when cold.

 

You could always buy a 1000watt block heater or crank the thermostat up to 80 degrees in your garage.

 

(Mail the utility bills to Subaru)

[MDW25gt]

how do you know it is not valve ticking? is this not normal?

 

what is "piston Slap"

 

Sounds like piston slap.

Get used to it, my friend. Once it starts, it's there to stay.

In my experience, trying different brands of expensive synthetic oil will only drain your wallet.

 

Our '02 OB gets the cheapest store brand SL/SM rated dino oil that I can find.

Mobile 1 5w30 made it sound like a piston skirt was ready to hammer through the cylinder wall.

 

Cheap-azz dino oil = (almost) quiet at cold start.

Expensive, hyped-up synthetics= unspeakably loud engine when cold.

 

You could always buy a 1000watt block heater or crank the thermostat up to 80 degrees in your garage.

 

(Mail the utility bills to Subaru)

[Tiny Clark]

The Subie engineers decided that in the best interest of public safety, they should remove just about all of the piston skirt (the two longish tangs at the bottom of the piston) that used to assist the piston in sliding back and forth in the cylinder.

[Scoobaroo]

how do you know it is not valve ticking? is this not normal?

 

what is "piston Slap"

 

Slight valve clicking is normal.

Boddi speaks of the infamous cold knock or tap associated with cold, short skirted pistons on 2.5 engines.

 

Do a search for "Subaru 2.5 cold piston slap".

 

Be prepared for hours of reading.

[MDW25gt]

If the design of the piston skirt was the problem, would not all 2.5's do it?

 

my 2.5 does not do this. my 2.2 did from time to time. after oil pump was replaced the noise was all but gone.

 

Slight valve clicking is normal.

Boddi speaks of the infamous cold knock or tap associated with cold, short skirted pistons on 2.5 engines.

 

Do a search for "Subaru 2.5 cold piston slap".

 

Be prepared for hours of reading.

[Boddi]

yep, I see the are just two things to do, live with it or change piston..... some body tell me that the piston clerans was to big.

[Scoobaroo]

If the design of the piston skirt was the problem, would not all 2.5's do it?

 

my 2.5 does not do this. my 2.2 did from time to time. after oil pump was replaced the noise was all but gone.

 

 

2.5's are susceptible to "the slap" due to ridiculously short piston skirts.

The shorter a piston is from crown to skirt, the less likely it is to ride squarely in the bore; especially when a few thousanths of an inch has worn off of the skirts and they are contracted. (i.e. cold)

In fact, so many 2.5's have the slap, that it could be considered a design characteristic of the engine.

 

 

A 2.5 is not a 2.2. It's a different animal. If your 2.2 had hydraulic valve lash adjusters and they were noisy, I would agree that an oil pump might be to blame.

 

Subaru has admitted that piston slap is a problem on 2.5's. That's why they designed "countermeasure" pistons to combat "the slap" and issued a bulletin about the issue.

People are often reluctant to believe that the major rotating parts in the bowels of their low mileage engines are to blame for noises even though it's often true as we endure this engineering frenzy to cut internal rotating mass and friction in engines.

[Balr14]

I think piston slap is related to break-in. If you drove it very gently for the first 600 - 800 miles the rings seat a bit better and you usually don't get the slap. Short skirts with few ring lands allows a lot of piston rocking if the rings are not seated just so. I don't think it hurts anything. A lot of high-performance cars in the 60s were purposely built very loose. They were horrible when you started them cold; hard to start, burned oil, awful racket, etc. But, as soon as they warmed up they were as smooth as glass.

[Tiny Clark]

Pistons are slightly smalller than the cylinder bore, which is one of the reasons we have rings on the pistons. With even .010" of an inch clearance, which is ABOUT the thickness of a sheet of paper, a piston will wiggle, or slap, in the cylinder if it isn't long enough to keep it from cocking back and forth too much.

 

huh, huh, he said "cocking", huh huh!!!!!

 

The subie design of these pistons suck. Let's meet the engineer in a dark alley somewhere...

 

Zappa also said, "The crux of the biscuit, is the apostrophe"

[Scoobaroo]

With even .010" of an inch clearance, which is ABOUT the thickness of a sheet of paper, a piston will wiggle, or slap, in the cylinder if it isn't long enough to keep it from cocking back and forth too much.

 

 

10 thousanths is WAAAAY loose. Subie piston-to-wall clearance is in the 2 thousanths range when new. 3 or 4 thousanths will give you "the slap" with a short skirt design.

 

2.5 piston skirts are coated with a black moly / polymer coating a few thousanths thick. My guess is that when the coating gets scuffed off of the skirts, the slap begins.

[blitz]

Another possibilty is the timing belt tensioner "cold-noise". I thought this problem was worked out by the '03 MY, but I'm not 100% sure.

[Gnuman]

Blitz, that Avitar of yours has bugged me for a while now. . .

What is that character? It almost looks like an O2 sensor, but not quite. . .

 

Can you tell me more about this "cold noise" that you mention as well? This is the first I've heard of it. . .

[blitz]

Gnuman, LOL! (no it's not "reservoir tip" )

 

Long story short, it's a vacuum tube. (a.k.a. "Tubeman"). It was drawn by an artist friend of mine at my request and it's done in the style of the Creem magazine "Boy Howdy" mascot.

 

There's actually a companion "distressed-looking" tubeman (furrowed brow and sweat-beads). Both were part of a small advertisment I ran in Guitar player Magazine almost 20 years ago for a kit to "Bulletproof your Marshall Amp". I learned a lesson in real-life politics on account of Marshall being by far the largest advertiser in Guitar Player during that period.

[Gnuman]

I take it, then, that Marshal was "not particularly pleased" with your advertisement, and pushed Guitar Player to can it?

[cookie]

to never have doubted that your icon was a tube. My tech stopped with the Fender Twin Reverb.

I imagine this guy just has the usual piston slap. The dealers have been good at finding and fixing the knock from the tensioners around here. There is a service bulletin on that one.

I think the bulletin on the piston slap goes like sargent Shultz..."I hear nothing!"

[Tiny Clark]

10 thousanths is WAAAAY loose. Subie piston-to-wall clearance is in the 2 thousanths range when new. 3 or 4 thousanths will give you "the slap" with a short skirt design.

 

2.5 piston skirts are coated with a black moly / polymer coating a few thousanths thick. My guess is that when the coating gets scuffed off of the skirts, the slap begins.

 

I din't know what the frikkin' clearance was, and didn't think it was as large as .010 either.

 

I was just trying to 'splain it in some sort of relevant terms that would make sense to someone who doesn't know what a piston skirt looks like.

 

Boddi, have a look at this: http://www.canadiandriver.com/articles/jk/020320.htm

[Boddi]

Hi all, but it is one thing, this tick come just from one cylinder. maybe i have another explicate of my problem. Last owner told my yesterday he had to change time-belt and two valve, because the engine has go over time and bend the valve on this cylinder. This probably has hurt the piston enough to make this tick .... if this is so critical. But how about to put some milliteck oil treatment in the oil......