Engine Knocking when cold.

I owned an 85 S-10 briefly that had a spun sleeve baring on one of the piston connecting rods. If you've ever heard one of these, you know that it sounds like wearing a metal helmet with no padding and having someone rapp on it with a metal pipe. CLACK CLACK CLACK.

 

Now- When I start my car up cold, the knocking from the Driver side of the engine I swear sounds like I'm going to slam my pistons through the head of the block. After about 45 seconds, the knocking all but subsides, or at least goes down to a level that doesn't make it sound like the engine is going to unwind itself.

 

I took the car in about 8k ago, (just before my 60k) and the mechanic said that despite my ticks, and clicks, the engine "sounds normal".

 

So- I wanted to know... does anyone elses engine knock like it's going to blow up for a few minutes when they start it cold? Especially in older suby's with 50+K miles...

 

Frankly- I'm sorta worried, but when the mechanic says "everything is normal" what do I believe? Since they told me it was "fine" when it was under warranty, as well as documented it in their system as such, if I take it back and there is a problem, am I out the cash to fix it or can I go to SOA and say "they told me it was fine when it was under warranty, now that it's not it suddenly has an issue" ..??

 

I've lost an engine before, through no fault of my own. And like that time, I had mechanics telling me "everything is fine" when it wasn't.

 

I dont have a lot of cash, and absolutely cannot afford to be without my car right now (life transitions are a bitch eh?)

 

I've always been a little meek when approaching mechanics and car dealers in general.. any pointers?

 

Thanks everyone..

What oil are you running and at what ambient temp when starting are you getting that noise?

It may be what Subaru refers to as "piston slap". My mom's 1990 Legacy sedan had it...more noticed when the weather was cold.

 

Make sure to keep the copy where they said it was normal just in case. I will see what I can find out, but I am pretty sure when explained, "piston slap" will be the answer..especially without them being able to experience/hear it personally.

 

If you get some "ticking", that is probably a lifter sticking. My mom's car did that when she would forget to change the oil for awhile. She eventually had to replace one from forgetting one too many times.....

What oil are you running and at what ambient temp when starting are you getting that noise?

 

Mobile One 5W-30 (Using synth since car had 3500mi)

Current temp out side is 25 degrees F

Last time it did this was just about 30 min ago, last time it was driven before that was on the morning commute, she sat for about 5 hours.

This sounds like a better description of the sound i get...but i don't think the temp really matters...mine only makes the sound after you let off the gas though..mine is probably something different

It may be what Subaru refers to as "piston slap". My mom's 1990 Legacy sedan had it...more noticed when the weather was cold.

 

Make sure to keep the copy where they said it was normal just in case. I will see what I can find out, but I am pretty sure when explained, "piston slap" will be the answer..especially without them being able to experience/hear it personally.

 

If you get some "ticking", that is probably a lifter sticking. My mom's car did that when she would forget to change the oil for awhile. She eventually had to replace one from forgetting one too many times.....

 

Piston slap is what it sounds like to me, it sounds so close to that S-10 I had I'm totaly freaked out by it. When I have to give it gas, man the motor sounds like it's going to spin itself right out.. like the noise rods make when they are bad.. really resonating & vibrating, like the exhaust covers do naturally, except 1000x worse... I always try to let her warm up, but I couldn't today.. I wasn't even getting on her, just lightly, as lightly as I could accelerating. I went approx 1/2 mile, and by that time, (another stop /start) it was gone.

My wife has an '04 Sedan, and we have the same problem. It had it the day we bought it but we just though it was because the car was sitting on the lot for so long. It's been getting constantly worse.

 

I had an '00 2.5RS with over 60,000 miles on it that I even took to track days, and it NEVER had this problem.

 

We have an appointment on Wednesday for it to be looked at a second time. Be sure to leave it overnight at the dealership so that they can start it up when it's cold.

 

Let us know how you make out.

This sounds like a better description of the sound i get...but i don't think the temp really matters...mine only makes the sound after you let off the gas though..mine is probably something different

 

Like a raspy metallic rattle/clack, when the car is rolling, but the pressure you put on the gas isn't enough to cause the drivetrane to kick in?

 

I get that too, only when it's warm out though...

 

My uncle thinks it's my cats..

 

I'm not so sure though..

na mine is just sitting with the e-brake on...you rev it to about 1500 rpms then let off...you get that metallic knock sound...like a bad rod or something? Does it all the time no matter how long the car has been running etc.

My wife has an '04 Sedan, and we have the same problem. It had it the day we bought it but we just though it was because the car was sitting on the lot for so long. It's been getting constantly worse.

 

I had an '00 2.5RS with over 60,000 miles on it that I even took to track days, and it NEVER had this problem.

 

We have an appointment on Wednesday for it to be looked at a second time. Be sure to leave it overnight at the dealership so that they can start it up when it's cold.

 

Let us know how you make out.

 

Not long after my initial appointment to have the clacking checked out, I test drove a 98 Impreza Outback sport with the 2.2LIi. I took special note as the mechanic said, and I quote "All subarus sound like that". But I was a little worried when that 98 with 167,000 miles on it sounded smoother than a relaxation tape. No rattles, clacks, clicks, ticks, or anything.

 

Personally,I think I'm getting the run around for one, because They are not the dealership of purchase, although I have gotten service and parts from them since moving.. (but will be moving again in 30 days.. so, I'll need a Detroit / Ann-Arbor Suby dealer soon)

Mainly, what I need is advice on approaching this situation with the service manager, and mechanic. I don't want to go inot their office and be like "You said my car is fine but I don't beleive you, check it again" because frankly, I know how that'll turn out.. *insert canned typical reply here* Or as greyson said "pistonslap".

 

How do I get these guys to see my POV without making them disinclined to helping me becuse in short, I'm accusing them of having not diagnosed an issue properly while my car was under warranty, and now it is not.

I'm also convinced that we have piston slap. The problem with piston slap is that it is rarely terminal. You will lose compression, and power, but rarely does the engine blow.

So they can say it's normal. It's not normal, and the only way I see you getting it fixed is with a real fight. Make sure you get SOA involved as soon as they deny your warranty claim. Which unless you have an extrodinary dealership, they WILL do.

It's not a cheap repair. So they will do everything in there power to not pay for it.

btw- My wife and I love your wagon. She really wants a wagon like her sedan. You both have the same exact car, color and all, except hers is a sedan and yours is a wagon.

maybe a lifter issue? any techs here have thoughts??

 

are there any other local Subaru dealers that you could get a second opinion? might be your best bet because the dealer you are talking to now can say it is normal until they/you are blue in the face and nothing will come of it.

 

my mom's would typically go away once it was warmed up....now the lifter tick would continue until she got the oil changed. in the winter, i would try to get her to use a lighter oil, but you seem to be using a pretty light one so I dont see the oil being the problem....but then again, i am no technician either..just a guy who sells them, advertises them and has owned a few of them.

 

btw- My wife and I love your wagon. She really wants a wagon like her sedan. You both have the same exact car, color and all, except hers is a sedan and yours is a wagon.

 

You just missed one!! we had a dark blue 2003 wagon with 13k on it!! crap.

our babies.... (from my wife's signature) I sold the RS to pay for my LGT. I miss her.

our babies.... (from my wife's signature) I sold the RS to pay for my LGT. I miss her.

 

Thanks for the Compliments on Meh Wagon C.O.S!.. I sure do love her!

Hey- I love her, but if you got $14,600 she's yours..

 

I was just in Columbus last Tuesday-Thursday (Worthington area).. lots of older subys down that way.

Based on you saying that it is temperature dependant and that it occurs on start up, my opinion is that it is either a lifter that is bleeding down or that it is "piston slap".

 

Piston stap is caused by the piston, itelf, expanding at a slower rate than the rest of the internals. This lets the piston rock in the bore during the top of the stroke. As Nathan said, it is rarely terminal. Many GM motors (3.4L, 5.7L, etc) have this issue from brand new. My '95 Z28 would knock when it was cold, if you put any load on the motor.

My neighbor's OB wagon clacked like a cement mixer.

Try Mobil1 TSUV 5w-40 if your winters don't stay -10F or lower.

I had a similar issue with my 05 wrx. A couple times last winter when I would start it up after a nights rest it would sound like the motor was going to blow for about 5 secs, then things would get quiet. I have never heard anything like this with any of me previous cars.

 

It hasn't happened with my lgt yet...

I thot there was a thread awhile back something to do with timing belt tensioners causing havoc.

Definately sounds like piston slap. Subies are becoming known for it.

 

One thing to keep in mind is that while synthetic oil is great it does not stick to parts well. So, it will provide great protection when/while the engine is running. However, when the engine is not running most of it drains down to the crank case. On start-up there is little oil coating the important parts. That may be causing a bit of your noise also.

 

I have piston slap when cold. I use synthetic oil with Lucas oil stabalizer. My piston slap sounds less with the stabalizer. Keep in mind that is with my calibrated ear just like my butt dyno, never fails....... Just $.02.

 

Peace,

 

Greg

b4

You should post that on bobistheoilguy.com. And watch the followup you'll get.

That is why I finished with the $.02 comment. I read that years ago and I do not remember where. I am a ME and really need to see the numbers to believe stuff. I made sense to me, the numbers looked right and I have been doing it ever since.

 

Peace,

 

Greg

Piston Slap. My 99 Legacy GT with the 2.5 dohc sounded like a diesel at about 0 degrees, but would quiet down within 4 minutes. Had 125k with no problems when I traded it.

 

My wife's 03 Outback with 20k has gotten progressively louder over the past 2winters. It raps for a couple minutes, then ticks for the next 15 minutes until completely warmed up. Dealer calls it a 'non-destructive engine knock' and said it is typical.

My 05 GT is noisy as hell on cold start ups. I just noticed this since The michigan weather drop to 20 degrees or so.