Jimmy Carbo Problems

[wanebo]

Hi,

I have a newly aquired 95 Jimmy. Couple of days ago it really lost power, etc. Took it to the dealership, they checked the codes, pulled the EGR and dumped a goodchunk of carbon ot of it. Ran fine for 2 days but now it is doing the same thing.

They showed me the EGR and I can pull it and clean it myself. My question is, How can I get the carbon cleaned out that is causing this recurring problem? Any fuel additives out there that will help? Do I need to pull the exhaust or something and chip it out?

Any help would be appreciated. Thanks.

 

[sled_dog]

Sounds like a crappy dealership. If they tell you "yeah it will happen, just clean this every week or so" find another shop. Something has to be causing it if its excessively carboning up.

 

[Roz]

i agree, there is a root problem here- have to find out why it carbs up. shouldnt be at all near that bad. most adds are going to make it worse. i need more info on it to help u.
condition of sparkpugs, does it smoke, smell like gas when its running...ect

 

[wanebo]

I dunnow

They told me it might last a week, it might last 5 years before it would catch another chunk.

That's the key (I think) is that the carbon is coming from somewhere else and the chunks are getting aght in the EG.

I bought the truck from someone I know andI know they drove it much slower and usually barely hit top gear and cruised right there. Probably a way that will cause carbon to build up in spots. Well, I tend to drive vehicles a bit harder and more at higher speeds so I assume that his might cause problems for a little while. The dealership that worked on it did know both of these facts when they did the work and I hesitate to blame them for trying to save me a little cash on something that could be onetime.

Thanks for the response though.

 

[Roz]

hmm sound very possible, i had that prob in my '74 firebird, was owned by old lady. cleaned it up a bit then fine. but all the junk in the lifter valley started beraking loose and bearing started going south. when i took it apart, i called about 4 different friends and took pics in complete aww at the amount and size of the chunks in there. seriosly 5-7" globs

 

[wanebo]

Other conditons

Actually it runs great when not experiencing this problem. Doesn't smoke or smell like gas and no SES lights or retained codes.

 

[wanebo]

Eiih Carumba

7" gobs of carbon balls in the valley! I am seriously in awe!

Had to be a manual and she was just chugging it around town.

I really do think the ways that this vehicle has been driven are at the root cause of the problem. I have known this vehicle for 7 years and it never had these problems before I started driving it on a regular basis.

Take it easy on me guys. I do drive ok, just a little bit above the norm for acceleration and speed and mostly highway. My GF I got this enigma from drove it mostly around town and a bit (I'm being polite here) below the norm for acceleration and speed.

Possible that the increase in the highway miles might be a big issue? Dunnoh.

 

[diesel4me]

not an uncommon problem..

At my friends garage,he had an S10 blazer come in with a 4.3 v6--it was skipping and had bad hesitation,and at times it would stall and be very hard to restart--it would crank and crank,then finally sputter to life,and it would only run in neutral--as soon as you put it in gear it would stall...after repeated attempts at starting it,it would pop back thru the intake manifold,and then it would fire right up and run normally...

We removed the catalitic converter--it was not plugged like we had suspected!...a tune up was done recently,so it was unlikely the plugs or wires,cap and rotor were faulty..we finally found the EGR valve(buried in the "valley" behind the water pump!...we removed it,and saw a LOT of carbon build up..we ran a drill bit thru the passages the best we could,and sucked out the carbon with a shop vac..put it back together,and it ran great!--the owner was estatic--he had brought it to several other places and spent 400 bucks with little or no results!..

But 2 weeks later it started doing the same thing again--we went right to the EGR valve again,and removed it--there were some smaller chunks of carbon,but nothing like the first time..we then put the EGR back on,but it did not run good!!--we later determined the EGR valve,which was electrically operated,had croaked--so we put a new one on (cost 50 bucks!)--and it ran sweet again...he has had no trouble since...

The chevy dealership nearby says there are lots of cars and trucks coming in with excessive carbon buildup in the engine--the Caddy "Northstar"engine seems to be the carbon king,and the V6 motors in many GM cars are noted for it also...I think the combination of cheap gas,and eldery drivers leads to carbon buildup..along with poor manifold design and the EGR valves contribute to the build up of carbon..

An engine can do all kinds of weird things when too much carbon buikds up,and not just ping or "detonate"..I've seen intake valves on some motors so encrusted with deposits the fuel air mix cant get past the valve stem into the combustion chamber!--and the motor feels like it has 20hp instaed of 100!...just removing the carbon made a world of difference!..
Our dealers have a "carbon removal" special,I think all they do is dump ATF or a commercial carbon remover down the intake and change the oil--for 99.95!

 

[shane74]

Hi,

I have a newly aquired 95 Jimmy. Couple of days ago it really lost power, etc. Took it to the dealership, they checked the codes, pulled the EGR and dumped a goodchunk of carbon ot of it. Ran fine for 2 days but now it is doing the same thing.

They showed me the EGR and I can pull it and clean it myself. My question is, How can I get the carbon cleaned out that is causing this recurring problem? Any fuel additives out there that will help? Do I need to pull the exhaust or something and chip it out?

Any help would be appreciated. Thanks.

Replace the EGR w/ an OEM unit. If they are not working properly, you will have a ton of carbon build up in there. They are supposed to open to keep the build up from happening. Do not use an aftermarket unit. They are a POS and they don't last very long. I got less than 1 year out of 2 different aftermarket units. I finally broke down and got an OEM replacement ($100 yikes!), but I now have zero problems with it.