'95 GMC Safari EGR problems

[MuRKRoW]

Hey everyone. As the title says, i'm having a few problems. First off, I've been having problems with my EGR valve for about a year now. Whenever my engine would heat up, the car would start stalling. I unplugged the clip from the valve so that I could continue driving my car, but have been getting around 8 to 10 miles per gallon which is why I decided to replace it with a brand new one. When I was taking my old EGR out, one of the 2 bolts that hold it in place snapped off only leaving a small amount of threads sticking out. There really isn't enough thread to get a vice grip onto the bolt to get a strong hold. I have a set of bits to back out the bolt, but they require a hole to be drilled into the middle of the bolt first and this bolt is eating up my metal bits with no effort! There are no markings on the head of the bolt so I can't say what grade it is. Does anyone have suggestions as to getting that bolt out? Right now I have the other side bolted in and then a c-clamp tightened down on the broken bolt side, but that is very temporary.

My second question has to do with check engine codes. When I start my car up, I have no "Service Engine Soon" light, but after driving for about 15 minutes, the light comes back on and my car begins to run fairly poor. This van is an OBDI so when I got home, I put a paperclip in pins "a" and "b" and collected the error codes. Here is what I got and the info I found on them:

3 pause 2 - Error 32 - EGR error

6 Pause 6 - Error 66 - 3-2 Control Solenoid Circuit Fault

6 Pause 7 - Error 67 - Torque Converter Clutch (TCC) Solenoid Circuit Fault

8 Pause 3 - Error 83 - Torque Converter Clutch (TCC) Solenoid Circuit Fault

Has anyone seen these before and know what causes each one? The EGR was brand new so I can exchange it if that's the problem. Thanks in advance if you can help!

[throrope]

Well that stinks.

I kept getting knock codes and lackluster power until I got the factory service manual. For me, the EGR was non-functional and caused the engine to ping. That set the knock code but the computer responded by retarding timing sapping power and I suppose mpg, but I'm past checking. I never got an EGR code.

Not that the above applies to you, but the twenty bucks I spent at Amazon for used GM M/L service and driveability manuals (two separate volumes) made all the difference. The troubleshooting guides and descriptions in the driveability manual explains it down to DNA.

As to the broken bolt, I'd seek out a good shop and let them have a go. The bolt is steel screwed into aluminum. Kind of like removing a diamond without disturbing the coal. Takes talent with the right gear. Unfortunately, based on my experience, if the EGR isn't right, it's not going to run right.

Good luck and keep us posted.

[MuRKRoW]

Well as far as the bolt goes, I was able to drill into it with a carbide & tungsten drill bit. I tried using the easy out bits that I had, but they did not make it budge. I tried using my drill and that couldn't even do it. I then used my hammer drill and as you can probably guess, I broke that side Here is an image of it:



After a little creative thinking and different approaches, I was able to come up with a solution:



I had a notched square steel plate which gave me enough of a lip to crank it down firmly. That solves my bolt issue. After calling the local automotive parts store where I bought the EGR valve, the guy told me that my error 32 was most likely because there was a leak at the EGR since I wasn't able to tighten it very well. The bad part is that after tightening the EGR very tightly, I still get those 4 error codes. What I find strange is that they all come on at the exact same time and it's after about 15 minutes of driving. I also notice a difference in the way my car idles when the codes come on and I get terrible gas mileage. Can someone tell me about these codes so I know what to look for?!

[throrope]

That's actually a great solution. The only other alternative is to replace the intake manifold. Good job!

I recall a thread here that included a website listing every code with description. A search should reveal it.

[chevymaher]

Well as far as the bolt goes, I was able to drill into it with a carbide & tungsten drill bit. I tried using the easy out bits that I had, but they did not make it budge. I tried using my drill and that couldn't even do it. I then used my hammer drill and as you can probably guess, I broke that side Here is an image of it:

[ http://img195.imageshack.us/img195/1100/photo0268c.jpg ]

After a little creative thinking and different approaches, I was able to come up with a solution:

[ http://img9.imageshack.us/img9/40/photo0269ie.jpg ]

I had a notched square steel plate which gave me enough of a lip to crank it down firmly. That solves my bolt issue. After calling the local automotive parts store where I bought the EGR valve, the guy told me that my error 32 was most likely because there was a leak at the EGR since I wasn't able to tighten it very well. The bad part is that after tightening the EGR very tightly, I still get those 4 error codes. What I find strange is that they all come on at the exact same time and it's after about 15 minutes of driving. I also notice a difference in the way my car idles when the codes come on and I get terrible gas mileage. Can someone tell me about these codes so I know what to look for?!

Clean it real good and use JB WELD Of course you will never get that stud back out again.Immediate problem is solved.

[MuRKRoW]

Yeah I was considering JB Weld also since I have some sitting on my desk. I may change it at a later date, but it sure is a hassle to get to! I'm still waiting on some info for those error codes!

[Jasen]

If you can't get it to seat and seal properly you can always cheat. Put a nice bead of RTV silicon on it, let sit for 24 hrs. and then install. I've had to do that a couple times on header flanges that just wouldn't seal up.

[chevymaher]

Yeah I was considering JB Weld also since I have some sitting on my desk. I may change it at a later date, but it sure is a hassle to get to! I'm still waiting on some info for those error codes!

All your error codes are coming from the same section of wiring harness.I would start at the tranny and work my way back cleaning all the plug ins.Clear the codes and see if they come back.If they do then start looking at parts involved.Seeing as how there so many it looks like a plug in to me.White corrosion inside the plug sending bad readings between post of the plug,nieboring connections and such and whatnot.

[Jasen]

Expanding on Chevymaher's thoughts. It also wouldn't be a bad idea to spray the plugs with WD, a blast of air and then apply dielectric grease to the inside and outside of the rubber seal.

[MuRKRoW]

Okay thanks for all the valuable info! There are only a dozen or 2 plugs that are visible unless I dig a little deeper so I will clean everything that I can and let you know the results!

[Lumpy]

I say JB Weld it. My local Ace Hardware has little threaded inserts in their "miles of aisles" of
hardware drawers. They're small OD, more like the kind carpenters use than the large OD
hardened kind you might use in an engine block. They're not threaded on the outside
they're knurled or fluted. And they have a flat, washer-like head. JB one of those suckers in and you'll
be able to tighten and remove your mounting bolt over and over again. Even though
you won't likely need to more than once or twice in it's lifetime.

I find all kinds of incredible stuff in those hardware bins at Ace.

JB claims you can drill and tap their hardened product. I've never tried it.
But on a part that's not going to see a lot of screwing and unscrewing, like this,
that too might be a workable answer.

Or simply leave that square thing on the back. That'll likely hold forever...


Lump