My 2016 V6-Chevy Silverado 1500 model currently at 140,000 mile when I bought it second hand from used car dealer,check engine light, came on after a week from the dealer , so 1st time brought to mechanic for system check…shop mechanic says that there is carbon build in the engine head cylinder, so told them to clean up all carbon build up cost me $1500.00 got the truck back , after two days driving, check engine light show on again…so brought back to mechanic. then they system check again…then they say two fuel enjector is missed firing…he said need to replace two fuel enjector but I said okey replacde all six-fuel enjector…I agreed to pay another $1500.00 after 3 weeks again the check engine came on again…Till now 07-25-2022 I have not bring back to mechanic, I don’t know what to do now with this truck…already spent $3,000.00 to get rid of the check engine light…these 2016 Silverado chevy truck is an unlikely model machine. Any body knows what the problem is?
I am not a mechanic but I know this much: You need a better one. Go to Autozone or someplace similar and have the stored check engine codes scanned. Post them here and someone who knows what they’re talking about can tell you what the likely problem is.
Good advice above, after you obtain the current diagnostic code(s), post them here for more ideas. I’m guessing the original code was for a misfire, p030X, where X is the cylinder that’s misfiring. If X=0, that’s the code for a multiple cylinder misfire. In any event, carbon deposits can get really hot & ignite the fuel/air mixture before the spark plugs have a chance, which results in a misfire, which must be why the shop cleaned the cylinder heads. That wouldn’t have been most mechanic’s first guess for a misfire code, at least if the mechanics hadn’t actually inspected the truck in their shop; but a de-carbon job may have made sense in your truck’s case.
Suggest to stop the replace-parts and see what happens diagnostic method, easy to run out of money before running out of things to replace. Instead use a scientific test- based method. Single cylinder misfires are typically diagnosed by swapping parts from cylinder to cylinder, a good diagnostic test to see if the misfire moves with the part swap. spark plugs, fuel injectors, coils, etc. For multiple cylinder misfires, after a quick visual inspection, the first test would probably be for fuel trim. Ask your shop about that, they may have the scan tool to obtain the fuel trim. You are welcome to post your shop’s real time frame shot data, which will include the fuel trim info, might get some other ideas here. Here’s a pretty good article on diagnosising misfires.
More carbon = higher compression = more power and better fuel economy! The down side is some carbon may break off and cause a valve to burn and you may need to buy higher octane gasoline.
I think a lot of carbon in an engine that’s under 200k miles is caused by leaking valve seals. The valve seals can get wrecked when someone drives 20k miles without changing the oil. This probably happened when the original owner bought it and then traded it in later, and had no incentive to maintain it since it was going to be traded in. The sludge damages the seals. Now you get oil leaking in to the cylinders because of bad valve seals. The oil turns to carbon.
It’s also got the LV3 4.3L. Which has direct injection, which makes an engine more prone to carbon build up on the intake valves.
I didn’t realize GM did this too in addition to Ford. The carbon build up is caused by the EGR and the lack of fuel mixing with the EGR gas to keep the valves clean. I believe the solution to this problem was to have both direct injection for performance and traditional intake port injection too to keep the EGR soot under control.
Is there a method shops can visually inspect an intake valve to see if it has any carbon build up, before removing the cylinder head(s)? I’d be surprised if a shop’s first step for a misfire code was to remove the head.
They can boroscope down the spark plug hole!
Maybe the borescope method would also allow a view of the top of the intake valve through the intake manifold.
The intake valves can be inspected and cleaned without removing the cylinder heads.
There is no upside to carbon build up. There should never be a “ need” to buy a higher octane than recommended if there is “a need” there is a problem that needs looking into. Carbon build ups can and will lead to hot spots on pistons, cylinder heads and valves. Any of which can lead to pre-detonation which no amount of extra octane will fix. Cracking of things like valves and in rare severe cases even the heads, none of which is a good thing.
And as far as:
I really hope you were joking because that is pure B.S.
What else would you expect from the SNOWMAN?
I was trying to exercise tact……"I know, I know, I still need practice, I need to work on tolerance too.
Years ago I owned a 1984 Pontiac Sunbird that was in proper tune but would knock on the recommended regular fuel. I spent the extra money and put unleaded plus in it and the knocking stopped. It happens.
Carbon on top of the pistons will raise the compression ratio causing knock.
Using a higher octane gas will eliminate it.
Tester
EGR doesn’t cause this, crankcase gasses cause this. The blowby past the rings enters the crankcase and is recirculated to the intake. The buildup on the valves for direct injection engines, you correctly stated, does not get washed off the intake valves. Some engines have both direct and indirect injectors to solve this. Some have elaborate catch cans that remove the liquids from the gas to minimize buildup.
Most engines have not had an EGR system for decades. EGR was designed to “pollute” the intake charge to reduce oxides of nitrogen. That is handled in the 3-way catalytic converters and with fuel control now.
Thanks I didn’t know that! So an easy but not right way to fix this whole problem would be to just simply vent the crank case to the atmosphere or exhaust. Or get some elaborate catch can from a better designed vehicle.
PvtPublic doesn’t believe that higher compression improves performance? That BMW that takes premium doesn’t perform better than a regular engine?
IIRC some auto manufacturers run their engines hotter to burn the carbon off the outside of the valves as another way to address direct injection carbon buildup.
Most manufacturers have been creeping up on coolant temps. Higher coolant temps means less heat energy wasted into the cooling.
I don’t think that would do a whole lot to clean up the intake valves.
just wondering if you run a catch can on your mustang and what you think of them? was thinking of getting one for my challenger whenever I get it. if it does not void the warranty.