Engine Rebuilder's view of GDI intake issues

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Originally Posted by WobblyElvis
My son has a 2008 Cadillac with a 3.6 GDI engine. Over 205,000 miles with no problems related to the DI. No valve cleaning maintenance whatsoever. Currently own a hyundai with GDI. 90,000 miles without any intake cleaning and it runs fine. I had an ecotec 2.2 [ not GDI ] that had the PCV port down low between the intake ports as mentioned in the article. Car went bye bye due to an accident with 231,000 miles on it. Burned a qt every 4,000 miles. I haven't experienced any problems with GM or GDi designs. Quality of some parts like GM timing chains is another story.

Your GDI is not exempt from buildup. Get that intake sprayed at-least. A can of CRC Intake Cleaner spray will keep your Hyundai running well.
 
Originally Posted by super20dan
Originally Posted by vivaUkraine
It's been what, like 50 years since American car companies been making poor cars and trucks. It amazes me how many "car guys" on BITOG buy used Chevys and Fords in 2020. Even in a very distant Ukraine, the glory of unreliability and poor craftsmanship of American cars was known, despite barely any American cars there. It's that famous. Why on Earth would someone get a 5-7 year old Chevy Equinox or similar, when there are Japanese? There is a perfect logical reason for domestic trio losing so much market share over the last 50 years. Yet there is no logical reason why there are so many not particularly bright Americans that still give them business, especially in a used market!!!
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Pick up trucks are the exception, but only because there are barely any substitutes from foreign brands.

no need to say anymore

Hopefully ever …
 
I get along fine with my GM products and since I manage global teams of 3.5-3.8 engineers … probably bright enough to not need your snarky opinions
 
Some of you guys make me laugh, ignoring the problem and putting a bandage on the symptom. Crazy!
fix the problem once and you will never see the symptom ever again.
 
In between carbs and PFI … I had a coupe TBI GM's … very reliable engines … but never seemed to make the power of the other variants …
I now have two DI and three PFI engines … and my only turbo is PFI
 
Originally Posted by 4WD
In between carbs and PFI … I had a coupe TBI GM's … very reliable engines … but never seemed to make the power of the other variants …
I now have two DI and three PFI engines … and my only turbo is PFI


I had a tbi 305 in my 89 Caprice. It had way less power than my 83 carbed 305. However, there were 332k miles on the tbi engine when it got scrapped due to rust. It had 150psi on 6 cylinders and 180 on the remaining 2 (carbon buildup)? We tore it down out of curiosity about 2 years later. Nothing major wrong, the cylinder walls had no crosshatch remaining but nothing really bad looking, very little ring ridge and no major carbon buildup.

I plan to take apart the current carbed 305 once I replace it with the 5.3 LM7. 240k miles, runs great. Has piston slap when cold but very little oil usage. I don't suspect much carbon buildup.
 
Originally Posted by 4WD
In between carbs and PFI … I had a coupe TBI GM's … very reliable engines … but never seemed to make the power of the other variants …
I now have two DI and three PFI engines … and my only turbo is PFI


I will admit that I enjoyed working on my 2002; it gave me an excuse to bring my ancient Craftsman Engine Analyzer out of storage.
 
Small USB borescope cameras that will go down a spark plug hole are pretty cheap now, sub $20. If you are really curious, you could get one and check it out.

Originally Posted by caprice_2nv
Originally Posted by Olas
Originally Posted by caprice_2nv
Originally Posted by Olas
GDI has never been a problem, never will be. we only feel this way because PFI used to fix a symptom, but PFI never fixed the problem. The problem stil exists, only difference is GDI does not address the symptom.

The problem is EGR and PCV used together - EGR introduces hot dry soot, PCV introduces cool, wet vapours. Put the two together and you get IVDs!

The solution is to re-engineer EGR and PCV systems so they dont cause the problem in the first place, OR, to leave systems unchanged and allow the problem to continue but start to address the symptoms again by way of fabricating a manifold to allow you to use PFI. mapping and calibrating this would be quite time consuming,

Carburettors are starting to look attractive again
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How does a carbed engine compare to PFI and gdi when it comes to valve deposits? Both my cars are carbureted with high mileage but I've never had the heads off to see the valves. Slight pinging on the 305 in warm weather but the EGR valve isn't functioning anymore, likely the cause. 350 Oldsmobile never pings ever.



Carbs have very clean manifolds and very clean heads/valves. You are delivering a constant stream of fuel across those componnentns, and fuel is a very effective parts cleaner. The only place you see any buildup in a carb engine is the piston crown, same as any other engine. (maintenance still applies, same as any other platform)


The intake manifold and lifter valley looked like brand new on my 1976 350 with high mileage. Wish I could see the pistons and valves.
 
Originally Posted by Triple_Se7en
Your GDI is not exempt from buildup. Get that intake sprayed at-least. A can of CRC Intake Cleaner spray will keep your Hyundai running well.

I'd rather not send dissolved crud etc. down to the cat converter.
I'll pull the manifold off and clean the valves when/if the day comes that performance changes.
 
Originally Posted by circuitsmith
Originally Posted by Triple_Se7en
Your GDI is not exempt from buildup. Get that intake sprayed at-least. A can of CRC Intake Cleaner spray will keep your Hyundai running well.

I'd rather not send dissolved crud etc. down to the cat converter.
I'll pull the manifold off and clean the valves when/if the day comes that performance changes.

Probably only 1% of GDI owners have the mechanical ability to do that.
Good for you. I am not in your mechanically-inclined shoes. So watch out cat, here comes dissolved crud.
 
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This is from the tailpipe of the '18 ACCENT . You'd think it's a diesel or an severe oil burning engine . I always us Top Tier gas , usually VALERO 88 w/E5 or 90 non E . Have used Techron concentrate once . The oil is Platinum 5w-20 that's been in use since 3,000 miles .

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Ethanol gasoline increases carbon. I won;t buy from stations advertising 5-10%.
Some top-tier gasolines have more detergent than others. (Mobil/Exxon - Shell and BP have the most. No Chevron here, but I heard that has a good amount.
 
Our choices are VALERO , SUNOCO and CITGO . Prefer VALERO for 88 w/E5 or 90 non E and being closer to us . CITGO and VALERO have the TOP TIER sticker on the pumps . SUNOCO , not the last I looked .
 
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Originally Posted by Triple_Se7en
Probably only 1% of GDI owners have the mechanical ability to do that.

Then they can do what the 99% do when faced with a job beyond their abilities: hire a professional.
 
Around here the majority will just keep driving with misfires, pinging, poor performance until the engine blows and either put a used engine in or trade the car.
 
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