Chevy 5.7 and cleaning

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Hi

I havent posted here in ages but thought I'd post a cleaning question for my old school Chevy Vortec 5.7. Last fall I finally found a nice old body style Chevy Tahoe 2dr that was a southern rust free truck.

After acquiring it, we recently did the MPFI upgrade and while having the upper intake off the truck, noticed how dirty the top of the lower intake was.

The engine seems to be a replacement as the odometer shows 198,000 miles yet goes over 3000 miles on a quart of Penz 5w-30 synthetic.

To gently clean this engine, rather than run a "cleaner" through it, when spring arrives, I think I will try running 15-40 Rotella through the engine.

Any thoughts of this?

Thanks
 
I dont have anything useful to add, but i thought id congratulate you on saying Vortec instead of vortex! People always say vortex and it drives me up a wall lol
 
Hi

Thanks
grin.gif
 
I’m not sure why you’d think that consumption and mileage has anything to do with a replacement engine?

I’d pop off a valve cover to see how dirty it is.

Personally, I’d just keep using Pennzoil 5w30 for the cleaning and change it every 3,000 miles.
 
Hi

The truck, if not the engine, has 200,000 miles. I have polled others with this engine /mileage combo and 3000 miles to a quart of synthetic is not typical, hence the replacement engine theory.

I am inclined to use HDEO, Rotella, for the cleaning on the lower intake. Possible a bad pcv was to blame at some point.
 
Does it leak oil? That would be the first thing I would check as opposed to assuming the missing oil is due to consumption. All that takes is a gasket replacement to fix.
 
Congrats on a nice truck (the 2 dr. Tahoe has always caught my eye) with a darn good engine.

I think you have two misconceptions we need to dispel.
Oil consumption is not directly related to mileage, especially on an engine that is capable of over twice as many miles as yours has on it. It's possible it's been changed but engines treated properly can consume very little oil for much longer than that - you'll maintain your Vortec 350 wrong if you believe it's impossible for an engine to show almost no wear at 200K.
Secondly, Rotella 15w40 is a good oil but only a good choice in this engine if it's being worked to its limit in very hot weather or has low oil pressure. It's also not ideal for cleaning it up inside - thicker oils don't flush dirt away as well as thinner ones. A high mileage synthetic or blend will suit this engine very well - my dad has a '97 Suburban that has logged over 250,000 miles on Valvoline Maxlife 10w30 or 10w40... beginning at 170,000 when he got it. That engine has over 430K overhaul-free miles on it and consumption hasn't increased noticeably since he got it. I rest my case.
 
Hi

Not sure why I would want to go to a blend for cleaning if I am already using Penz Plat 5w-30.

The Rotella is only for cleaning up the mess a sticky pcv may have left. Btw, this engine has metal backed lower intakes which the '97 orig engine were not built with. With the cleanliness of the external surface of the engine, I feel it was likely replaced.

When I got it in Oct, I replaced all rad hoses and flushed the Dex out and filled with G-05, a Hybrid OAT I have used for years.

I fluid filmed the truck before the snow came, so the nasty salt should have negligible opportunity to do its work.
 
Ah, sorry - I glanced up at Nick1994's reply to double check the type/weight and he didn't say synthetic. No, there's no compelling reason to move back to a syn blend from that oil. If there's other evidence it was replaced then it may have been, but that information wasn't in your original post. I still wouldn't use 15w40 to "clean up" an engine that will otherwise see 5- or 10w30.
 
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Quote:
"Does it leak oil? That would be the first thing I would check as opposed to assuming the missing oil is due to consumption. All that takes is a gasket replacement to fix."


No leaks. 3000 miles to a qt is very acceptable. :) It appears this engine doesn't have a consumption problem.

I wanted to clean up the nasty mess caused likely by a $3.00 pcv a prior owner neglected.
 
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I'd stick to the PP or PUP 5W-30 if you want further cleaning. I don't know with a 100% certainty, but I don't think there's a better cleaning oil on the market, and according to Pennzoil, there isn't.
 
The intake and heads may have been bolted to a new'ish short block, w/o cleaning ...

I'd run whatever you want for oil and toss a full can of BG109 in there 100 miles before every change. Drive that last 100 miles around town w/o revving the life out of it, and then do filter and oil
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Due to the heat riser crossover in the manifold, they always back-on some crud to the underside. Perfectly normal
smile.gif
 
Hi

This one looked somewhat worse than what I saw on y-tube. Perhaps I will just keep going with the Penz Plat and change at 5000k.
 
I have a 1997 GMC Sierra with the 5.7 Vortec. It only has 85,000 miles and only sees 1,000 milers per year and sits in the garage most of the time. I change the oil(Castrol GTX 5w30)once per year or 1,000 miles and it burns zero oil in that OCI.
 
My 1995 K3500 (7.4 liter, not 5.7) has 284,000 and uses 1 quart in 2500-3000 driven lightly
(if its being worked hard, it'll use a quart in 1800-2000 or so) - Original engine, never rebuilt

15W-40 most all it's life..
usually TSC Traveler or Cenex(Land o' lakes) 15W-40,
sometimes SuperTech from walmart.
 
Originally Posted By: ChevyMan93
! People always say vortex and it drives me up a wall lol


For me its people who think they run "Mobile 1" in their vehicles.
 
Originally Posted By: lght1
Hi

I havent posted here in ages but thought I'd post a cleaning question for my old school Chevy Vortec 5.7. Last fall I finally found a nice old body style Chevy Tahoe 2dr that was a southern rust free truck.

After acquiring it, we recently did the MPFI upgrade and while having the upper intake off the truck, noticed how dirty the top of the lower intake was.

The engine seems to be a replacement as the odometer shows 198,000 miles yet goes over 3000 miles on a quart of Penz 5w-30 synthetic.

To gently clean this engine, rather than run a "cleaner" through it, when spring arrives, I think I will try running 15-40 Rotella through the engine.

Any thoughts of this?

Thanks


198,000 miles is nothing for that engine. I guy I worked with has a 98 with the 350 vortec and he has over 400,000 miles on the original engine so don't assume yours is a replacement engine unless it looks new or something.

I also have a 98 chevy with the 350 that I bought new and it has always used about a quart in 3,000 miles since new. Mine only has about 135,000 miles on it.

Kind of off topic but I recently picked up a NIB BWD new style injection setup for mine off CL for $100. Did you have to use a new bracket for your conversion or did you re-use the old one? I've heard it both ways so I'm not sure. Mine did not come with a new bracket and the instructions say that you have to purchase it separately. Any other tips on doing this conversion? Mine still runs fine but did have a injector stick awhile back after the truck sat for a couple of months without starting.
 
I wouldn't assume a replacement either. I have 4 Vortec 5.7 engines beyond 300k on original engines, smacking around 12,000 lbs. if truck and load all day long. All city driving, plenty of stop and go, plenty of starts and shut downs.
 
I have a 98 and that oil consumption seems normal. As for cleaning, you can run what you want but I would change it more often. I also am a believer in the HDEO especially for cleaning faster. I have used 15-40 a few times and currently have Delo blend HDEO in 10-30 with 1 qt of Mobil 1 5-30 in it. Seems to like it is still running fine at 178k miles.
 
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