valvetrain noise/what oil

[91l98z28]

I have a 91 camaro with a mostly stock (~260HP) 350/5.7.. has 95,000mi on it.

garaged overnight, coldest startup is no colder than 40*F.

valve guide seals are worn (puff of blue on startup, I know I can't "fix" this with oil)

currently running M1 10w30 for about 6 months (4000mi) per change, with an AC filter. the car does have an oil cooler (the type that fits between the block and filter, and has coolant running through it).

on about 1 out of every 5 starts, there is valvetrain noise (lifter) that lasts for about 30 seconds until oil hits the top end.

uses a bit less than 1qt every 4000 miles

Use is about 50% highway commuting (1800rpm in sixth gear (97 camaro T56 trans)), and 50% blasting around town with frequent runs past 3500rpm..

I have no problems with oil pressure - 45psi going down the highway at 1800, 30 at hot idle, 50-55 at cold startup.

my goals:

(1) reduce/eliminate cold startup lifter noise as much as possible

(2) not signifigantly worsen the puff of smoke at startup due to the worn valve guide seal issue

(3) not signifigantly increase consumption

I don't care so much about motor life, as it will probably be pulled and rebuilt well before it hits 150,000.

I plan to switch to a donaldson or fleetguard synethetic media filter, and want to try a different oil, to help reach my goals. thinking about m1 5w30 or maybe delvac 5w40, but i have no real brand allegience and just want to use whatever is the best attempt at my goals.

my reasoning for picking a thinner 'cold' oil and a premium filter is to get oil flow to the top of the motor (and thus into the valvetrain) as fast as possible. I don't know much about the cars past, other than that it's been using M1 10w30 for the past 10,000+ miles.

thoughts/advice?

 

[Patman]

For starters, you should try out a 5w30 or 0w30 oil if you want the oil to flow faster to the valvetrain.

Look for an oil which also has a viscosity of about 11cst at 100c or higher, that way it's a middle to thick 30wt. Mobil 1 10w30 is on the thinner side of things and doesn't seem to do so well in GM V8s.

I'm currently running German made Castrol Syntec 0w30 in my 95 LT1 Firebird Formula with good results, but I know Amsoil 0w30 or 5w30, or Redline 5w30 would also work very well too. I also wouldn't hesitate to recommend a good 5w40 or 0w40 oil, so long as it's formulated on the thinner side (between 12.5 to 14cst at 100c that is)

 

[KW]

Rotella T 5W40 might be a good choice in this one. It has a strong detergant package that might clean up the sticky lifter. And should help with the oil use.

 

[Dr. T]

You want a diesel oil to help clean things out +/- help resuscitate the valve seals (if possible)...my vote goes to Delvac 1.

 

[heyjay]

quote:

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Originally posted by Dr. T:
You want a diesel oil to help clean things out +/- help resuscitate the valve seals (if possible)...my vote goes to Delvac 1.

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Ditto.

If you can't afford or can't find Delvac 1, try a high quality 15W-40.

The Delvac 1 5W-40 will reduce your oil consumption too, so I strongly recommend it.

Jerry

 

[dickwells]

To me, noise on one out of five starts brings the backflow prevention valve on the filter into question.

 

[91l98z28]

just to add a few bits of info to my original post:

i'm currently using a 1218 filter, i believe it does include an ADBV, but my understanding is it's not necessary because the small block chevy has a vertical mounted filter. to dickwells - does the anti-drainback valve mean the same thing as backflow valve? Since the filter is vertical I don't think it helps - but if it was somehow defective could it actually hurt? come to think of it...i don't think the car ever had this problem before the last oil/filter change.... i never thought of that.

the startup lifter noise noise is only after the car has been sitting a while (couple days) since the last startup. if driven daily - no noise ever. but let it sit a few days, and then you get the 1-in-5 chance of lifter noise on the initial cold startup.

patman: how does the 0w30 do on cold startup... is it possible to go "too thin"?

i think i will probably try the delvac 1, seems pretty much agreed that it's a better oil than m1 10w30 in all aspects.

 

[Motorbike]

Your L98 has one or more of the hydraulic roller lifters bleeding down , no fix for that other than replacement but they will last a very long time that way .

 

[Patman]

quote:

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Originally posted by 91l98z28:


patman: how does the 0w30 do on cold startup... is it possible to go "too thin"?

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No, because any 0w oil is going to still be considerably thicker when cold than even a 20w50 oil would be when hot

 

[DavoNF]

If the car lives in California, and with that mileage, I would use nothing less than a 15W-40, and would even give Mobil 1 15W-50 a go. Try Delo 400 diesel oil as well.

Your lifter noise is caused by dirt, not as a result of your oil viscosity.

I live in a climate similar to yours, my Windsor V8 has had nothing but a diet of 15W-40 all its life, and with 141,000 miles on the clock runs like a charm.

Try it, you will be pleasantly surprised

Dave

[ February 16, 2004, 03:43 PM: Message edited by: DavoNF ]

 

[Drew99GT]

I seriously do not think oil flow on cold start is what's causing your lifter issues. 10w in temps abover 40 degrees, especially 10w-30 Mobil 1, is not impeading flow to the top of the motor. I agree that it is most likely the anti-drainback valve in the filter coupled with Mobil 1. In my particular car, Mobil 1 seems to slide right past the anti-drainback valve and I get outrageous noise. With a conventional high mileage type oil, the filter stays full, even after a few days of not starting at a all, and it is silent upon a cold start, even at below 0 temps. I'd be inclined to use a 10w-30 high mileage oil for your application. It may help valve seals slightly, and it is thicker in general, not to mention having a slightly higher HT/HS viscosity for those "spirated" driving moments