Carbon in EGR Valve

[BlazerLT]

Originally Posted by MT-2500

BlazerLT looks like you have been doing a little home work. On the 95 4.3 V6.
Carbon ball codes in the old EGR valve are Kinda like a 02 sensor codes.
Do not throw parts at it untill you check it out.
Proper testing would be in order. Could be the nut kit or cpi injector unit or one of many other things.
I thing for sure the screen in the egr valve gasket will save a lot of removing and reinstalling the erg valve untill the problem is found.
MT

But with all due respect intended, wouldn't it be better to get the carbon out of the engine instead of being trapped in the screen which will hinder EGR flow over time and potentially increase combustion temperatures and pinging when the inert EGR gases is restricted?

[MT-2500]

Originally Posted by BlazerLT

But with all due respect intended, wouldn't it be better to get the carbon out of the engine instead of being trapped in the screen which will hinder EGR flow over time and potentially increase combustion temperatures and pinging when the inert EGR gases is restricted?

Well I have never had one make that many carbon balls to stop up the port and shut off the egr flow.
The screen is more to keep them from getting under the egr valve.
But it could be possiable restrict flow if it make hole lot of them.
A person shoould pull the egr valve and check it from time to time is there is any flow problems.
MT

[Chris Stewart]

Hi Gang, hope it's OK for me to sit with you at the "grown folks table".
My experience with a screened EGR passage has been good for many years on my '92. I'm not sure if it was my leaky lines or 2 leaky regulators or even just accumilated carbon like my old carbed Chevys, loosened carbon was/is still the result. The possibility of a clogged EGR passage interests me. The lack of inert gasses to cool the combustion process and resulting knock activates the knock sensors which quickly retard the ignition timing so no damage occurs but at what cost?
Would there be a detected power loss?
What about fuel milage?
What besides an EGR removal and check would indicate a clogged passage?

[MT-2500]

Originally Posted by Chris Stewart

Hi Gang, hope it's OK for me to sit with you at the "grown folks table".
My experience with a screened EGR passage has been good for many years on my '92. I'm not sure if it was my leaky lines or 2 leaky regulators or even just accumilated carbon like my old carbed Chevys, loosened carbon was/is still the result. The possibility of a clogged EGR passage interests me. The lack of inert gasses to cool the combustion process and resulting knock activates the knock sensors which quickly retard the ignition timing so no damage occurs but at what cost?
Would there be a detected power loss?
What about fuel milage?
What besides an EGR removal and check would indicate a clogged passage?

You are welcome to jump in any where and give us your ideas and experiance on it.
Actually if EGR valve is blocked or not working you will have a little more power but it will cut fuel mileage a little and may cause some spark knock.
But newer VCM /PVM computers will detect no egr valve flow and should set a code if it has no or restricted egr valve flow.
I always like the screen in the gasket to keep the spit balls out of the egr valve but a blazerLT pointed out it could led to restricted EGR valve flow.
You can not win for losing. Just do the best with what you have.
It seemes to me like all of the 4.3 v6 go threw the old spit ball in the egr valve making at some time in there life.
And some get over it after a while.
The cause could be one of many things. Gas additives,fuel mixture not right or engine not running right and as BlazerLT said the nut kit or internal fuel leakage inside the plantuim or even needing a good tune up..
MT

[BillNeugent]

I had the same problem with my 95 s10. Black smoke coming out of the exhast and a clogged EGR valve. Dealer put it on the computer and found that the coolant temp sensor was bad. Changed the sensor and never had the problem again.

[Chris Stewart]

That makes sense. Bet the mpg's improved too.
The stem on the '92 plug valve gets a "coating" that causes it to stick open every now and then...been about a year ago. I remove the EGR and work the plug valve in and out until it frees up then reinstall for another years service.

[blazes9395]

I've used the tomco gasket on the 95 I had, put it in as soon as I got the truck, about 100,000kms on it before I sold it, never had a problem with it. I understand LT what your saying, but I would rather have the carbon only go as far as the screen, then give me intermittent idle problems and stuff.

[BlazerLT]

Originally Posted by blazes9395

I've used the tomco gasket on the 95 I had, put it in as soon as I got the truck, about 100,000kms on it before I sold it, never had a problem with it. I understand LT what your saying, but I would rather have the carbon only go as far as the screen, then give me intermittent idle problems and stuff.

True, I understand your point.

But after the actual cause (CPI / nutkit) is fixed, you won't ever have a carbon problem again. You might have a couple chunk but after that, smooth sailing, I haven't had one single chunk of carbon since I fixed everything.

But to each there own, just wanted to let people know what MIGHT occur with the screen.