Cold start... I didn't know I had a diesel?! (Please Help!)

[T_F_E]

Alright so this problem has been going on since I got the car whenever it gets below about 32 degrees F. This problem lasts for about 5 minutes of driving I would say. It may be getting worse but I'm not to sure, a youtube video is below for your viewing (dis)pleasure. Please guys I really need help on this one!

http://www.youtube.com/watch?v=OGcEWXkqxTk

[Huffer]

What kind of oil + grade are you running?

[T_F_E]

Synthetic 5W-30, I can't remember exactly the brand.

[Huffer]

The brand does matter, but I would try switching to a slightly thicker grade to see if that quietens the noise down.

Most likely what you have is a lack of expansion of the pistons to fill the cylinder when they're cold - I don't know if you park indoors or not; if outdoors then the motor is going to get colder faster - that accelerates the wear.

If you have access to an electrical outlet, consider spending the $25 to get a block heater installed and then just plug it in whenever you park - it'll keep the coolant warm, and therefore the block will be warmer and there'll be less wear on startup.

If the noise goes away after the car is warmed up, then I believe you have a rather loud case of piston slap...
My car sounded rather gruff when we had -0C temps a couple of weeks ago...

[T_F_E]

The brand does matter, but I would try switching to a slightly thicker grade to see if that quietens the noise down.

Most likely what you have is a lack of expansion of the pistons to fill the cylinder when they're cold - I don't know if you park indoors or not; if outdoors then the motor is going to get colder faster - that accelerates the wear.

If you have access to an electrical outlet, consider spending the $25 to get a block heater installed and then just plug it in whenever you park - it'll keep the coolant warm, and therefore the block will be warmer and there'll be less wear on startup.

If the noise goes away after the car is warmed up, then I believe you have a rather loud case of piston slap...
My car sounded rather gruff when we had -0C temps a couple of weeks ago...

I park in a garage and I have a block heater, when using the heater it does help in the morning but the problem is still around, it does go away after the car is warmed up though, what is piston slap?

[Huffer]

piston slap = is the sound caused when the pistons do not expand enough to fill the cylinder - there is a slight gap which results in a mechanical sound not dissimilar to what you hear prior to the engine being warmed up. This is common on all 95-04 Subaru's, in varying extents of sound.

It is not normally an issue - and usually switching to a heavier/thicker grade of oil removes the sound or quietens it.

I run 10w40 in the summer, and usually 10w30 in the winter. In the subzero temps I do have a little more difficulty starting up. Also, Mobil 1 oils are typically more viscous than their competitors at the same oil weight rating.

[T_F_E]

First off thanks for everything you have no idea how much I appreciate it. So are you saying switch to 10W30? I have to change oil this weekend. I will also remember the mobil 1 tip. Will using this oil cause damage because it is thicker and using it in the winter? It doesnt get below zero to often here. So your thinkin this is probably piston slap and not something like lifters going bad? Thanks again

[StatGSR]

Welcome to the world of subaru motors. pretty much a very common issure with many suby motors. you should hear the racket mine makes all the time haha.

im guna have to go against the huffers advise on going to heavier weight oil for the winter time, i personally dont think its smart or do i think it will help the problem, just make the car harder to start in the morning.

[anothernord]

+1 for the block heater, I installed mine before this winter and I can tell you it is more than worth the ~$30. Cold starts are easier, the heater warms up faster, and like Huffer said, it saves engine wear.

[T_F_E]

+1 for the block heater, I installed mine before this winter and I can tell you it is more than worth the ~$30. Cold starts are easier, the heater warms up faster, and like Huffer said, it saves engine wear.

yeah as said above I have one, its works great im still getting this on start up but I love having quick heat! I'm going by the rule "plug it under 20" seems to work ok

[SubaGlue]

i bought a 98 GT wagon with 150,000 on it. I did an oil change and a few hundred miles later piston slap started. I took it to a few mechanics and they said that the engine was fu**ed. I drove it a few more hundred miles and the noise just got worse and worse and the car got slower and slower.

I finally decided to take it somewhere to getthe engine taken apart. on the way i could barely get it going from a stop, so i had to run so many stop signs just to keep going. Finally the engine gave- the rod went through the block and started a small fire under the hood.

Its hard to hear the sound exactly with the youtube quality, but it sounded something like that. My piston is now sitting on my desk as we speak.....

[T_F_E]

i bought a 98 GT wagon with 150,000 on it. I did an oil change and a few hundred miles later piston slap started. I took it to a few mechanics and they said that the engine was fu**ed. I drove it a few more hundred miles and the noise just got worse and worse and the car got slower and slower.

I finally decided to take it somewhere to getthe engine taken apart. on the way i could barely get it going from a stop, so i had to run so many stop signs just to keep going. Finally the engine gave- the rod went through the block and started a small fire under the hood.

Its hard to hear the sound exactly with the youtube quality, but it sounded something like that. My piston is now sitting on my desk as we speak.....

holy shit....

[SubaGlue]

yeah IF it is piston slap, its pretty damn serious

[T_F_E]

Sound is absolutely identical to this video....

http://www.youtube.com/watch?v=7NVjR4CY ... re=related (http://www.youtube.com/watch?v=7NVjR4CYrCw&feature=related)

[SubaGlue]

Yep thats the sound from what I can hear. Those 2 vids arent nearly as bad as mine was, but basically the rod was coming loose from the crank if im not mistaken, so at thousands of revs a minute, shit goes bad fast. I didnt even drive my car 1,000 mi before it died on me. I dont want to tell you it is definitely piston slap, but im afraid it most likely is. Sorry to hear man and best of luck

[sexystover]

Yep thats the sound from what I can hear. Those 2 vids arent nearly as bad as mine was, but basically the rod was coming loose from the crank if im not mistaken, so at thousands of revs a minute, shit goes bad fast. I didnt even drive my car 1,000 mi before it died on me. I dont want to tell you it is definitely piston slap, but im afraid it most likely is. Sorry to hear man and best of luck

what you had isnt piston slap, its rod knock, very big difference

[Huffer]

yeah IF it is piston slap, its pretty damn serious

No it's not. What you had wasn't piston slap - you had rod knock. Completely different.

TFE: The only reason I recommended you switch to a heavier grade oil is because you have a block heater and a garage. If you plug the car in all the time, the oil viscosity will be fine to start the car in the mornings because the block itself will be warmer. If you didn't have a block heater I would have recommended an oil change using a good quality oil that "clings" to surfaces after you shut off the engine. Mobil 1 tends to NOT cling, it is actually thinner than it's weight rating.

[T_F_E]

yeah IF it is piston slap, its pretty damn serious

No it's not. What you had wasn't piston slap - you had rod knock. Completely different.

TFE: The only reason I recommended you switch to a heavier grade oil is because you have a block heater and a garage. If you plug the car in all the time, the oil viscosity will be fine to start the car in the mornings because the block itself will be warmer. If you didn't have a block heater I would have recommended an oil change using a good quality oil that "clings" to surfaces after you shut off the engine. Mobil 1 tends to NOT cling, it is actually thinner than it's weight rating.

Alright, see thats just the morning though, My car then sit in the school parking lot for 8 hours almost always below 32 degrees, So I think I will stick with 5W-30 any brand recommendation for the circumstances now?

[Huffer]

I run Castrol Syntec semi-synth year round... my car sits outside year round.

if your still looking for an explanation, it may be a valve cover not opening...

just a thought

[slaytalera]

mine and my budys suby (1st gen legacy wagon) have the same noise. to qoute my dad "i always hated subaru engines, they always sound like they're about to blow up" :lol:

[SubaGlue]

No it's not. What you had wasn't piston slap - you had rod knock. Completely different.

What is piston slap then? what is happening?

[Stang70Fastback]

Lol, that first video is exactly my car. I have the exact same issue. When I start it, it's really loud, then it fades in and out after a minute or two, then after another two minutes it's gone. I usually let the car warm up until the noise goes away, because if it is the pistons "slapping" I don't want to cause any extra wear.

[Huffer]

What is piston slap then? what is happening?

If you read the first posts of this thread... :-(

[SubaGlue]

right... :oops:

Sorry to scare you OP. All of the mechanics I went too told me it was piston slap, and mine sounded a lot like those vids. Hope u have better circumstances than i did

[Stang70Fastback]

If it makes you feel any better OP, mine's been making that exact noise (though it's slowly getting worse) for over a year now...