Pics - Top Piston Cleaning - Lexus CT200h

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Long time member here. Finally coming back since my 2jz turbo days running GC. Now driving something more economical. I just picked up a used Lexus CT200h with 125k miles. Previous fills were done at the dealership 0w20 conventional. After the first week of owning it I noticed high oil consumption 0.5qt/600mi so I did a top piston soak with MMO and GM top engine cleaner. Hoping to free up the piston rings and planning on running Synthetic Maxlife 10w30 (or any suggestion?). The first 2 pics are after an overnight soak of MMO. The carbon was very soft and was easily scraped off when my endoscope touched the carbon. The 2nd 2 pics are after a 2nd night soak with 50/50 mix of MMO and GM and a couple dry cranks. Last pic is from the last the soak.

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Originally Posted by OilUzer
0W20 comes in dino?
Thanks for spotting that. Not sure. The previous owner only did oil changes at the dealer.
 
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Looks good. You'd have (eventually) gotten there with just the MMO seeing's how it's mostly kerosene and Stoddard solvent... but the GM cleaner helped it along. Last I recall Chevron was mfg the ACdelco top end cleaner, if that's still the case it's a good bet there's some Techron in it. Nicely done..👍
 
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pbm

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Originally Posted by Mad_Hatter
Looks good. You'd have (eventually) gotten there with just the MMO seeing's how it's mostly kerosene and Stoddard solvent... but the GM cleaner helped it along. Last I recall Chevron was mfg the ACdelco top end cleaner, if that's still the case it's a good bet there's some Techron in it. Nicely done..👍
Would adding actual Techron to the MMO accomplish the same thing since it's easier to procure the the GM stuff?
 
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Nice work. I'm interested how the consumption does moving forward. I'm trying, and having success using kreen in my alitima oil burner (2009). All I've done is treated the oil and the fuel and have reduced the usage by a significant amount but I think I'll do and ounce in each cylinder overnight when I get some time over thanksgiving. Love seeing results like this, good job!
 
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Atlanta,GA
I'd bet the vehicle never spent more than an hour at highway speeds.
Originally Posted by D1dad
Nice work. I'm interested how the consumption does moving forward. I'm trying, and having success using kreen in my alitima oil burner (2009). All I've done is treated the oil and the fuel and have reduced the usage by a significant amount but I think I'll do and ounce in each cylinder overnight when I get some time over thanksgiving. Love seeing results like this, good job!
Expect it to return. I'd bet the vehicle has never spent more than an hour at highway speeds let alone speeds of 70 mph or more. The OP just as likely would've reduced consumption by just going on an extended road trip.
 
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Do a piston soak with Berryman B-12 Chemtool and all of the carbon will be removed and if the rings are partially stuck due to carbon those will be loosened as well.
 
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Originally Posted by jbutch
I wonder if using Top Tier gas would help prevent this?
Using TT fuel will certainly minimize deposits but I don't think TT makes any guarantee that you won't get ANY deposits. Excessive carbon buildup can happen due to leaky injectors or excessive oil in the combustion chamber due to loose rings or valve seals for example, no TT fuel can remedy that. But whatever you use to keep the carbon on the piston tops to a minimum is better than nothing. Too much carbon can cause a host of problems. Berrymans is my personal go to for piston soaking but I've used MMO before..in fact I used MMO when I replaced the plugs last year. I figured since I had the plenum off I might as well soak the pistons on that bank (1). Soak the pistons, change the oil and call it good. I don't get to soak the bank 1 pistons very often because it's kind of PITA to take that plenum off.
Originally Posted by pbm
Would adding actual Techron to the MMO accomplish the same thing since it's easier to procure the the GM stuff?
Don't see why not.
 
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Originally Posted by OilUzer
0W20 comes in dino?
Most "full synthetics" are what had been referred to as "Synthetic Blends". But to answer your question, the lower tier of 0W20 are blends of synthetic and refined mineral oils, The upper tier products - Mobil 1 AP, Amsoil SS - are majority synthetic base oils from what we can glean from SDS and performance data like MRV and ASTM D5800.08 NOACK volatility. And synthetic oil products are NOT made in a lab despite ridiculously incredible advertising. Developed? Yes; Manufactured ? NO.
 
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Yes you cleaned the tops of the pistons.. but how did they get so much carbon? Likely your valve stem seals. SInce you mention oil consumption that is a likely culprit. How did the plugs look?
 
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Looks Great!
Originally Posted by Mad_Hatter
Last I recall Chevron was mfg the ACdelco top end cleaner, if that's still the case it's a good bet there's some Techron in it.
Nope............................... Techron only works in the presence of heat, not at room temp
 
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Originally Posted by Linctex
Looks Great!
Originally Posted by Mad_Hatter
Last I recall Chevron was mfg the ACdelco top end cleaner, if that's still the case it's a good bet there's some Techron in it.
Nope............................... Techron only works in the presence of heat, not at room temp
I knew it (pea) was one of the few cleaners that can survive the high temps in the combustion chamber long enough to be effective but wasn't sure if it was heat "activated"...tx for clearing that up. So in the case of this piston soak, the solvent in the MMO did the trick, no??
 
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Originally Posted by JC1
Looks good. Thanks for the Pics. How much MMO and GM cleaner did you use in each cylinder?
300ml MMO and 100ml of GM per cylinder
 
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Originally Posted by krismoriah72
Yes you cleaned the tops of the pistons.. but how did they get so much carbon? Likely your valve stem seals. SInce you mention oil consumption that is a likely culprit. How did the plugs look?
I hope it penetrated to the rings. That was the main goal. First soak - all the chemicals flowed through and the pistons were dry in the morning. 2nd soak was similar but improved. Plugs looked good. The base had carbon deposits but the tips were all clean on all 4 of them. Debated on replacing them but kept them and still runs smooth.
 
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EGR cooler, EGR valve, and EGR passages in the manifold are likely clogged----common problem with these.
 
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