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| Andrew S |
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I seem to have a little piston slap for about 30 seconds after a cold start up. Searches tell me its fairly common and not the end of the world, however they also suggest a change in the brand of oil used. So what do you guys think would be a good choice of oil for the Au? It has 360 ks and otherwise performs really well.
_________________ So many women - so little time |
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| ILLaViTaR |
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Motul is probably the best stuff but probably overkill. I think those engines use 10w40 or something you can go thicker but it's not really recommended. I put some 20w60 in my EB (dual fuel) and it still slaps on startup. Oil pressure didn't really increase either, I was running 15w40 before that or whatever the factory recommended is.
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| tearlejc |
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Nulon seems to be good - my mum's EB was doing this, changed to Nulon high kilometre, seemed to fix it..
_________________ 351 4V XB Coupe running LPG |
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| low_ryda |
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Did anyone think that maybe it's not 'piston slap'?
No disrespect intended but I'm unaware of any piston issues with these engines until at least an atmosphere of boost is pushed up them. Even with 360,000kms. Usually the top end will go, followed by the bottom end, never piston failure unless it's from something that shouldn't be. EA's suffer piston failure occasionally because they are aluminium which is a terrible material for pistons. The el onwards used hypereutetic pistons AFAIK and solved the problem. Worn rings are worn rings no matter what piston or bore. I believe you just have valve train noise which is common. It's caused by a dirty valvetrain rack blocking the flow of oil to the top end on start up causing lifter rattle usually, either that or worn mechanical components. I have fixed this in all my blue ovals by adding lucas oil stabiliser (having said that I run penrite so not cheap base oil). A better quality syn oil may do that same but at the end of the day it's mechanical wear. There is no substitute for replacement.
_________________ Not to get technical, but according to chemistry alcohol is a solution. |
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| Andrew S |
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I've just added about 600mls Helix HX7 synthetic to top up the level. Has restarted from cold several times now with only about 5 seconds of noise which is also much quieter.
Don't know if its pistons or valve train as suggested but at the next complete oil change (which will be with this HX7) it could go away completely.
_________________ So many women - so little time |
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| mick au2 |
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this might sound a bit extreme, but it could be your oil pump not delivering adequate pressure, or the oil galleries could be gummed up?
_________________ My cars don't advertise for Unit, Metal Mulisha, Loosekid Industries, Inverted, Famous stars & straps crap, R.M. Williams, Fusion, DC Shoes or the Transformers. |
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| chicho11 |
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NWclassifieds/Autos- Research It: Auto Q&A
James E. Harris, proprietor of Engine Restorations in Portland, Maine also disagrees with GM’s assertions regarding piston slap: One way to check for piston slap: Remove three spark plugs, leaving number one in place. Crank the engine over until you feel the resistance of number one piston coming up on compression. Crank against compression until the piston is about half way up the cylinder. Now using the fan, rock the crankshaft back and forth and listen for a metallic knocking sound. If you hear a knock, you have piston slap and the only way out is to rebuild the engine. reference: http://www.pistonslap.com/whatisit.htm |
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| efxr6wagon |
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I'm also getting what sounds like mild piston slap for 30-60 seconds on cold start in my 236,000km AU2 XR6 VCT. It's hardly noticeable, and does it for less than a minute a day, so it doesn't really bother me.
I'm using top-shelf Royal Purple HPR full-synthetic 10W30 oil - the grade specified for the car. As the VCT system is oil pressure activated, I hesitate to experiment with thicker oils in case that somehow messes with the VCT. I can live with the minor noise.
_________________ 95 EF XR6 wagon, 17" FTRs, DBA rotors, KYB/Koni, AU bottom end, ported EF head, backcut valves, SS Inductions, Territory intake, 10.2 CR, Auckland 1258 cam, vernier gear, PH4480 headers, no cat, Tickford 2.5", 2800rpm stall, J3 chip |
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| 67RCE |
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The noise is the lifters having bled down. Not piston slap.
_________________ ILL60 - EF XR8, Sunroof, Ticky Kit, 19x8.5/19x11 TE37's, 347, AFr185's, TFS BoxRcustom converter, Hurst Quarterstick, huge billet cam. |
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| mick au2 |
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piston slap noise sounds alot different to noisy lifters, (HLA's)
_________________ My cars don't advertise for Unit, Metal Mulisha, Loosekid Industries, Inverted, Famous stars & straps crap, R.M. Williams, Fusion, DC Shoes or the Transformers. |
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| efxr6wagon |
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Yep, different sound. My AU rarely has lifter noise, but when it does, it's only about one second of tick-tick-tick. My EF does it regularly for about 3 seconds or so. The sound my AU is making for the first 30-60 seconds on cold start is deeper - more like a light, irregular knock. Most people would probably never notice it (I guess that makes me an enthusiast
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_________________ 95 EF XR6 wagon, 17" FTRs, DBA rotors, KYB/Koni, AU bottom end, ported EF head, backcut valves, SS Inductions, Territory intake, 10.2 CR, Auckland 1258 cam, vernier gear, PH4480 headers, no cat, Tickford 2.5", 2800rpm stall, J3 chip |
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| TROYMAN |
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in my experience, when an engine is suffereing piston slap it will also blow alot of oil smoke, if there is enough movement on the bore for slap, the rings wont be sealing to well neither and will generally get worse as the engine warms up....
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| mick au2 |
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the only time ive heard piston slap was on a mates LC Torana 173ci red engine bout 20 yrs ago, I thought the big ends were gone in it, but after pulling the head off, all the pistons could be moved around the bore with about 2 play in the bores, must of had a slight rebore sometime and they used the original pistons, with new rings, well that was my assumption at the time.
_________________ My cars don't advertise for Unit, Metal Mulisha, Loosekid Industries, Inverted, Famous stars & straps crap, R.M. Williams, Fusion, DC Shoes or the Transformers. |
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| 4.0L I6 |
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Sometimes they can tick more than intended but eventually go away if you take it easy enough driving. I can compare big time between an EF and AU since i upgraded. The AU is a good solid cheap car. Excellent on gas too.
Just try your luck with thicker oil? could even be a lifter in need of adjusting.
_________________ 99 AU Falcon Forte in Galaxy Blue. Stock as a rock atm. Future Mods; Full sports exhaust, cam upgrade. |
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| wrongwaynorris |
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I use Nulon 40 W 70 in my 370,000 k EF and it works a treat . Better oil pressure now that it had new with 20 W 50 . I seriously doubt you have piston slap if it goes away after 30 seconds , more than likely lifters pumping up . Also try using a Ryco Z9HE filter witht the non return drain valve which holds oil in the top end of the engine .
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