What is the GM decarbonization process? Please no flames this is my first vette... :D

 

Disconnect the pcv line by the throttle body and insert a long funnel into the vaccum source end...SLOWLY pour 2 cans of GM top engine cleaner into the funnel while an assistant in the car maintains idle...When you get to the end of the 2nd can,allow the vehicle to stall,creating a fog effect in the motor...Let sit for 24 hours...The neighbors will love it when you start it the next day :lol: When the smoke clears,change the oil to get rid of any contaminats in the crankcase...Works wonders...

This procedure beats removing the spark plugs and pouring the top engine cleaner into the cylinders,because it will clean the intake and valves...And not as messy ;)

 

That's neat - a lazy man version of decarbonation! Thanks for the tip.

 

Decarbonation is when you leave the cap off the soda bottle :D

 

I have it on my PC@Home and I will post it later tonight when I get home.. :seeya

 

:lol: Shoot, I forgot the 'iz' combination. But you are right.

 

Thanks!!!

Will be watching for it...

:cheers:

 

Here ya go! :cheers: :seeya

This was posted by C4C5Specialist back in the day..

I felt it necessary to fill you all in on how to de-carbon your engines. Here is the reason. For most all situations, knock on a stock c5 will be due to carbon buildup, plain and simple. While there is a lot of speculation, fact is that out of 51 different c5 that I have performed this procedure, NONE have returned. There will always be the occasional one that this may NOT apply to, but for the most part, it should work. Also, just a side note, if your c5 is modified, even with just a MAF, this may not work, due to other issues, so do not ASSUME that this is a fix all.
Okay, first thing, go down to your GM dealer and purchase 2 cans of liquid top engine cleaner #1050002. That’s the part number. And get oil and filter, as you will have to change the oil after this procedure.
Second, let the car sit until it gets cold before you start this procedure.
Now, are you ready???? First, remove all spark plugs.
Next, evenly divide the 2 cans to feed 8 cylinders.
Remember that this will get messy, so have plenty of rags around, and put something under your car, and not all the cylinders will take all the chemical.
Next, add the cleaner to each cylinder, some may pour out, and some may take all of it. I leave rags under each plughole.
Then, pop a cold one because the cleaner must sit at least 6 hours, I like to see 12, but at least 6 are the minimum.
The next morning or whatever put a bunch of rags over all the plugholes, as you must crank over the engine to expel the entire cleaner. It’s going to leave a mess, so be warned. Crank over then engine for about 15 seconds, that’s all it takes. Clean up all the residual off the manifolds, with brake cleaner or something. Install the plugs.
Roll the vehicle outside, cause MAN is this going to smoke, and stink. Start it up, it will run rough for a while, this is common, and it will smoke too. Allow to idle for 20 mins. Then shut the engine down, and change the oil and filter.
The cleaner dilutes the oil so we don’t want to drive the car until after all has been consumed in the chamber, and the oil is warm.
Ok, now for the test drive, go to a highway, and drive a highway speeds for about 20 mins, to expel the cleaner from the exhaust. The car WILL smoke for some of the test drive, this is NORMAL. But by the time that you get back, it should be pretty much gone.
Ok, that’s it. Just remember, this is informational, nothing more. You may get some oxygen codes or some misfire until the cleaner is burned off, this is NORMAL. Just reset the codes, and you will be fine.
I have had a lot of success with this, as have some of the members that I have emailed this process to, but you must follow it exactly, thanks.
Best to all, and I remain, c4c5 specialist
------------------
c4c5mechanic, GM certified in all areas. ASE master certification w/L1. Club Corvette of CT member.

 

:D :D :D

Thanks again!

 

Hi all,
I can certify that C5 TECH's way of doing this is WAY EASIER and EFFECTIVE, since I did this on my '97 about nine months ago. It was a breeze and the car spit some serious black soot out the backend the day after. Make sure you push it out of the garage and CLOSE YOUR GARAGE, as you don't want that stink in your garage! There will be ALOT of white smoke coming out of the engine upon initial startup, too. Anyway, I had my trusty wife :rolleyes: holding down the peddle to keep the car from dying, until I got the 2 cans poured in. How hard can it be to keep the engine at a steady idle.......don't ask! My idle was VERY NOTICABLY smoother and the car ran much better after this treatment. I think I am going to do this again soon, as I just did the PCV mod and have alot of oil in the air compressor filter already after a few hundred miles of NORMAL driving, much less hard driving! I'm sure there is some buildup in there again.

Steve

 

Thanks for the info... I'll do this when it is time to change the oil next!

Patrick :cheers:

 

O.K. - I'll volunteer as today's idiot. It says "Disconnect the pcv line by the throttle body and insert a long funnel into the vaccum source end." Does that mean to pull the pcv and stick the funnel in the hole in the intake manifold that the pcv came out of? How far?

Thanks - I'll go back to my room now.

 

George,

Yes, that is what it means. The cleaner will be sucked down into the manifold, into the heads, into the cylinders. All of which will be cleaned by the solvent.


:cheers:

 

Thanks folks - that procedure sounds like a winner!

 

I'm a little confused... you disconnect the tube from the throttle body (inline after the airbride and coupler) and stick a funnel in the tube where it was connected? Anyone have a picture? :D

Patrick :cheers:

 

And, what effect does this process have on the catalytic converters, if any?


[Modified by EHS, 1:12 PM 12/12/2002]

 

I've been having ongoing problems with our 99 such as light pinging when accelerating, reduced performance at WOT and poor fuel economy. I've never gotten any type of code or service engine light etc. I've tried several different gases and driven about 1200 miles now with this condition. So far I've removed the Hypertech just in case, changed the fuel filter and talked to everyone who would stand still for a minute. Several CF members suggested I see the dealer which I finally broke down and did today. When I first spoke with them I was told they could find nothing wrong at all. In their words, it's just the way it left the factory and runs perfect. I mentioned buying the GM Top End cleaner and doing the decarbon process this weekend and he said they offer the same service and will guarantee me that all carbon will be removed for $116.00 so I had to say do it. He called me back this evening and said it was all done, but naturally he couldn't tell me it ran any better because it was already perfect. I'll pick it up tomorrow and if the problems seemed to have been taken care of, I'll share that and if there are no changes, I'll just ask for more ideas until I get it fixed. The car's in great shape and always ran very strong so it was easy to tell when the performance fell off. Sorry about the book and thanks again for the ears. :cheers:

 

:lol: :lol: :lol: :lol: :lol:

That cracked me up!!

I hope your perfect running car runs even better when you get it back.. :lol: Just kiddin ya.. :D

No serioulsy - let us know how it goes.. :seeya

 

When should you do this process? Do you wait for a certain number of miles or for the car to start acting up?

Thx!

 

That's what I'm wondering. Do you put the funnel/cleaner in the hose before or after the PCV valve at the back of the manifold? Why not just pull the entire PVC hose assembly off and pour fluid directly into the valve cover? :confused: help :confused: