1997 (JDM) Impreza WRX engine noise

[frqnt]

I\'ve got a \'97 WRX; ca. 120,000k\'s, completely stock and has been maintained to a good standard.

I test drove the car after I met the seller and he had travelled an hour or so to meet me so didn\'t notice any abnormal noise in the engine (assume because engine was warm).

Now, having owned it for a few days, I notice there is a small amount of piston slap(?). In my around town driving, it\'s yet to subside. It\'s very subtle and can\'t be heard over the (factory) exhaust/turbo spool at higher revs.

Should I worry or is this problem negligible in these engines? (reading mixed opinions)

I\'ll compression test later this week; what figures should the engine with this many km\'s be achieving?

What oil can anyone recommend to mitigate the sound? I\'ve read mixed reviews on-line from North American forums so thought I\'d ask those closer to home.

With regard to warming this thing up; when the temp gauge reaches it\'s median, is the sensor reading the block or is it the oil temp? I ask because when I drove it home (Tauranga to Auckland) I heard it backfire a few times but when I drive around town the temp gauge reads the same and obviously the car was a lot warmer when it was BF\'ing so I\'m trying to understand how to understand my wrx better.

Who is most fit to diagnose this properly for me in Auckland?

Ta muchly in advance.

[Timmah]

Does your car sound similar to this:

when cold? That\'s piston slap.

Piston slap is common in these cars. Just be nice to your car when it\'s cold.

Temp gauge reads water temp

Oil is a touchy subject. I use Castrol Magnatec 10w40 and does the job. I doubt it will mitigate the noise though.

Check out the Auckland section of the forums and I\'m sure someone will come have a look, or go to an Auckland meet

[frqnt]

Cheers dude. Sounds like that but not so loud. I was kinda hoping someone would suggest it may be a lifter problem.

I will see if I can find a member here to check it out for me or ask for a recommendation for a mechanic in the AKL thread.

[Timmah]

 frqnt said:

Cheers dude. Sounds like that but not so loud. I was kinda hoping someone would suggest it may be a lifter problem.

I will see if I can find a member here to check it out for me or ask for a recommendation for a mechanic in the AKL thread.

Being 1997, you should have solid lifters.

That\'s what my car sounds like any time it\'s not hot

[boon]

My MY97 WRX had wicked piston slap, sounded like a little diesel when it was cold, and I sold that a few years ago to some young fullas who proceeded to thrash the tits off it, it\'s still going strong so I wouldn\'t worry about it.

[shore_boy]

 boon said:

My MY97 WRX had wicked piston slap, sounded like a little diesel when it was cold, and I sold that a few years ago to some young fullas who proceeded to thrash the tits off it, it\'s still going strong so I wouldn\'t worry about it.

Sounds like my last WRX also. It\'s quite common when they\'re cold from what I understand.

[boon]

 shore_boy']

[quote name='boon said:

My MY97 WRX had wicked piston slap, sounded like a little diesel when it was cold, and I sold that a few years ago to some young fullas who proceeded to thrash the tits off it, it\'s still going strong so I wouldn\'t worry about it.

/quote]

Sounds like my last WRX also. It\'s quite common when they\'re cold from what I understand.

It\'s from people thrashing them when they\'re cold, the piston heats up way faster than the bore and results in the tolerances in the whole assembly being a little larger than intended.

[frqnt]

 boon said:

It\'s from people thrashing them when they\'re cold, the piston heats up way faster than the bore and results in the tolerances in the whole assembly being a little larger than intended.

So essentially my whip has been treated like a b*tch. This echoes my experience with piston slap on other vehicles but I\'ve read comments online that insinuate the problem is inherent in these engines.

Based on your comment and my experience; I\'d say the only thing inherent is that owners of these things can\'t resist driving aggressively when the engine is inadequately warm?

[Timmah]

 frqnt']

[quote name='boon said:

It\'s from people thrashing them when they\'re cold, the piston heats up way faster than the bore and results in the tolerances in the whole assembly being a little larger than intended.

/quote]

So essentially my whip has been treated like a b*tch. This echoes my experience with piston slap on other vehicles but I\'ve read comments online that insinuate the problem is inherent in these engines.

Based on your comment and my experience; I\'d say the only thing inherent is that owners of these things can\'t resist driving aggressively when the engine is inadequately warm?

For what it\'s worth, my car has sounded like that since 120,000ks and as you mentioned, is a lot louder. It\'s at 150,000k now and doesn\'t sound any louder. Sadly people do thrash the car when cold + the engine does get old so things will loosen up.

Regular oil changes and being kind to the car when cold = many worry free years.