quieted my piston slap (cold start knock)
10-26-2004, 11:55 AM
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quieted my piston slap (cold start knock) I've experimented with several different synthetics and just recently decided to try dino oil again. Went to Walmart and purchased Penzoil 5W30 for something like 7 bucks per 5 quart jug.
Anyway, my cold start knock noise has decreased drastically! What a difference! The mornings have been getting close to freezing and normally my motor would knock loud. I'll probably do an oil analysis and change more frequently, but just thought I'd share. I know that others have had similiar experiences.
Anyway, my cold start knock noise has decreased drastically! What a difference! The mornings have been getting close to freezing and normally my motor would knock loud. I'll probably do an oil analysis and change more frequently, but just thought I'd share. I know that others have had similiar experiences.
10-27-2004, 08:01 AM
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I found this and it worked great(at least on cold start slap)......
Found a GM tech that was sharing his login & password in the GM techline private Tech forums and came across an interesting tech conversation about cold startup piston slap, the kind that disappears after the engine gets up to normal operating temp. The tech stated that they had great luck with running Top End cleaner through the intake using the two bottle method allowing the first one to draw slowly through the PCV or brake booster vacuum and then letting the second bottle choke out the motor and then let it sit for 3-4 hrs suggesting the problem has a lot to do with carbon build up and perhaps the fact that we do consume some oil is a contributing factor . I tried this last night and man what a smoke show, white smoke filled the laneway, my neighbors laneway and half way down the street ....... but now there is only a slight knock,tick at warm up, barely audible, not even close to what it did sound like, definitely a huge improvement. Next oil change I will try this one more time and see if I can eliminate the noise all together
Just thought I would share... worked for me
Found a GM tech that was sharing his login & password in the GM techline private Tech forums and came across an interesting tech conversation about cold startup piston slap, the kind that disappears after the engine gets up to normal operating temp. The tech stated that they had great luck with running Top End cleaner through the intake using the two bottle method allowing the first one to draw slowly through the PCV or brake booster vacuum and then letting the second bottle choke out the motor and then let it sit for 3-4 hrs suggesting the problem has a lot to do with carbon build up and perhaps the fact that we do consume some oil is a contributing factor . I tried this last night and man what a smoke show, white smoke filled the laneway, my neighbors laneway and half way down the street ....... but now there is only a slight knock,tick at warm up, barely audible, not even close to what it did sound like, definitely a huge improvement. Next oil change I will try this one more time and see if I can eliminate the noise all together
Just thought I would share... worked for me
10-27-2004, 08:44 AM
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last i remember, quaker state and penzoil has parafin wax in them. if you've ever opened a motor up and seen huge globs of oily deposits in the lifter valley that you removed in chunks, that's it. parafin wax is also used by hair salons.
10-27-2004, 08:51 AM
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The "Pennsylvania" oils are parrafinic and I quit using
them after my first SBC rebuild, when I tore down I
found all of the internal surfaces coated with black
wax. I did not find that comforting.
them after my first SBC rebuild, when I tore down I
found all of the internal surfaces coated with black
wax. I did not find that comforting.
10-27-2004, 10:49 AM
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Pennzoil is one of the best Group II+ base dino oils on the market today. It's additive package is very strong and the rumors of it sludging up your motor are from the 1970 and 80's where manufacturer's called for longer drain intervals than what the oil's were up to. Adding to the fact that alot of manufacturer's called for 10W-40 which is the most prone to shearing due to the wide spread in viscosity. When an oil shears it leaves deposits behind and after awhile you will notice the dark color sludge.
To learn more Bobistheoilguy.com forums section
To learn more Bobistheoilguy.com forums section
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10-27-2004, 10:59 AM
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Originally Posted by jimmyblue
The "Pennsylvania" oils are parrafinic and I quit using
them after my first SBC rebuild, when I tore down I
found all of the internal surfaces coated with black
wax. I did not find that comforting.
them after my first SBC rebuild, when I tore down I
found all of the internal surfaces coated with black
wax. I did not find that comforting.
10-28-2004, 04:37 PM
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Is this the same as the backfiring noise when you let off the gas when the engine is cold? Like, accelerate in 1st to 2Krpms, then let off and click 2nd and it makes a horrid backfire noise. Like a popping.
10-28-2004, 05:12 PM
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Originally Posted by Slowhawk
We run Valvoline 10w30 in most of our LS1 forged motor's and they have no piston slap noise.On the other cars we run Mobile 0w40 and they are just as quiet.
10-28-2004, 05:19 PM
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Ive never used synthetic. I think the best thing to do b4 racing is to change the oil and filter. The change in oil pressure is noticible. The gauge shows 20psi more oil pressure throughout the rpm range. Fresh oil is less sensitive to heat. I change the oil based on this rather than mileage. When the oil pressure drops a lot as the engine gets hotter, I know its time for new oil.
Ive always wanted to try a synthetic but think having fresh clean oil is more important. Synthetic is too expensive to change often. Maybe it doesnt need to.
Ive always wanted to try a synthetic but think having fresh clean oil is more important. Synthetic is too expensive to change often. Maybe it doesnt need to.
10-28-2004, 05:46 PM
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Originally Posted by J&JsTA
I found this and it worked great(at least on cold start slap)......
Found a GM tech that was sharing his login & password in the GM techline private Tech forums and came across an interesting tech conversation about cold startup piston slap, the kind that disappears after the engine gets up to normal operating temp. The tech stated that they had great luck with running Top End cleaner through the intake using the two bottle method allowing the first one to draw slowly through the PCV or brake booster vacuum and then letting the second bottle choke out the motor and then let it sit for 3-4 hrs suggesting the problem has a lot to do with carbon build up and perhaps the fact that we do consume some oil is a contributing factor . I tried this last night and man what a smoke show, white smoke filled the laneway, my neighbors laneway and half way down the street ....... but now there is only a slight knock,tick at warm up, barely audible, not even close to what it did sound like, definitely a huge improvement. Next oil change I will try this one more time and see if I can eliminate the noise all together
Just thought I would share... worked for me
Found a GM tech that was sharing his login & password in the GM techline private Tech forums and came across an interesting tech conversation about cold startup piston slap, the kind that disappears after the engine gets up to normal operating temp. The tech stated that they had great luck with running Top End cleaner through the intake using the two bottle method allowing the first one to draw slowly through the PCV or brake booster vacuum and then letting the second bottle choke out the motor and then let it sit for 3-4 hrs suggesting the problem has a lot to do with carbon build up and perhaps the fact that we do consume some oil is a contributing factor . I tried this last night and man what a smoke show, white smoke filled the laneway, my neighbors laneway and half way down the street ....... but now there is only a slight knock,tick at warm up, barely audible, not even close to what it did sound like, definitely a huge improvement. Next oil change I will try this one more time and see if I can eliminate the noise all together
Just thought I would share... worked for me
10-28-2004, 06:11 PM
#17
um i would be carful dumping that stuff in the motor, that stuff doesnt compress like gas so if u put top end cleaner in like that real fast, if it doesnt compress good, say by by to your connecting rods and block. and yes i have seen this happen if its not run slow through the pcv line.
10-28-2004, 06:14 PM
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Originally Posted by dug
Ive never used synthetic. I think the best thing to do b4 racing is to change the oil and filter. The change in oil pressure is noticible. The gauge shows 20psi more oil pressure throughout the rpm range. Fresh oil is less sensitive to heat. I change the oil based on this rather than mileage. When the oil pressure drops a lot as the engine gets hotter, I know its time for new oil.
Ive always wanted to try a synthetic but think having fresh clean oil is more important. Synthetic is too expensive to change often. Maybe it doesnt need to.
Ive always wanted to try a synthetic but think having fresh clean oil is more important. Synthetic is too expensive to change often. Maybe it doesnt need to.
10-28-2004, 06:24 PM
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Could be but I think its from the oil getting old and dirty. It seems that the older the oil gets the more sensitive to heat. When the oil is new, the oil pressure stays strong even when hot. As it gets older the oil pressure drops a lot more as the engine gets hot. It has always been like that even when the engine was stock.