EGR Bolt hole repair

GEJ · Post by **GEJ** » Thu Jul 05, 2007 9:02 pm

The van I have is a 1994 LT "w" 4.3. For sometime I have been complaining about a ruff idle from time to time and poor power,poor gas mileage.I used this van for a dolly tow and when I got home the check engine light was on.I had it scaned and found a EGR code.I had the shop that did the scan take off the EGR and clean it without putting in a Tomco screen gasket.At that time,they told me one of the bolt holes was weak and they couldn't tighten the bolt down.That the intake needed to be taken off and cleaned and do a heil coil repair.I went to NECO and was telling everyone how without towing anything the van was bogging going up the hills in cruse.Well sure enough it came up with a code again.I knew it was the EGR again.

So not true to form for me,I read almost all the posts about EGR problems on both sites.Learned a lot.I found out about Tomco.Went to their site and need to know who is a outlet in the Roch NY area.I couldn't get the site to tell me that.

Also not lately true to form for me,(but that will change from this post forward)I took off the EGR myself this time.Sure enough their was a pc of carbon stuck in there.The bolt hole towards the center of the engine was not tight at all.Once I got the outside bolt out,the EGR was so loose that I could move the EGR around easily.I could see from the angle of the hole how someone from the past could cross thread or miss thread this bolt in the center of the engine.I need to know if anyone has done a heil coil repair without taking the intake off on this bolt hole.Maybe removing the thermo housing to make room.I read where a member replaced the bolts with studs and lock tight them in.I see the value in that and that is what I want to do in the course of this repair.

Even thro it was some minor wrenching on this so far,I got tell you all how good it felt.I got to tell you I didn't remember what I had been missing.But I'm back now with a fire lite in me from NECO.After this-look out Ole Yellar,I coming for you next!!!!!!.

crash · Post by **crash** » Fri Jul 06, 2007 4:44 am

hey gary... good to hear you got your hands all dirty. it's fun eh?

my 94 also has some bad threads for the bolt on the left side of the EGR. i never actually tried heli-coil simply because it's so darn tight in there. the bolt on mine was threading in at least 1/2 - 3/4 of the way then it would stop. I decided to save the headaches and bleeding knuckles and bought a little box of thick washers that fit the bolts. I think I ended up using 3 or 4 but that was enough to allow the bolt to tighten up and keep that side sealed.

As for the tomko kleen screen. were you able to find one??

If not, we sell them at my parts store ... (different brand) they are around $25 ... I mailed one out to the west coast last year for a member that couldn't locate one locally.

SafariRob · Post by **SafariRob** » Fri Jul 06, 2007 5:16 am

Gary, is it possible to chase the threads with a tap to make them usable again? I've had some luck by doing this in the past with aluminum. Getting the tap started correctly is the tricky part--if that's not done right, the threads really get destroyed. But if it goes well, you can end up with something to get a stud into.

BLAZER · Post by **BLAZER** » Fri Jul 06, 2007 5:42 am

Welcome to the word of the W motors, I've had 2 95's and both ran rough at idle, no matter what I replaced, my van is slowly getting worse lately.
I don't see why you can't do it in the van, just going to be pretty tight. I have had the upper intake off may time, canget it off i less than an hour, the bottom though, I've never had off, alot more attached to it that would have to be removed.
How I would tackle it.....I would get a larger tap, maybe switch that one bolt over to a larger standard bolt and try that. If not, then I would go after the helicoil and go that route. You can also get a screened gasket at Advance auto for around $10 in the HELP section. Comes in a pack of two different styles.

GEJ · Post by **GEJ** » Sat Jul 07, 2007 1:18 am

Rob-the threads are in tack.You just can't tighten the bolt.It will thread,but...

Blazer-thanks for the lead on where to get the screen gasket.

I talked to a NAPA parts guy.He told me since the screen gasket came out long ago that many other things have also come out.Heated screen gaskets,upgraded heated EGR's and alike.As far as the bolt repair,I will be putting in a studs on Monday/Tuesday this week with a heli coil repair and locktite.

As far as the heated screen gaskets and or the upgraded heated EGR which doesn't need a screen I am alittle confused about those.Anyone ever use either of them?.

As far as sea foam and running the engine to dislodge carbon I am alittle afraid of that.In years past,anytime I have done things like that with engines that had any kind of miles on them,I ended up removing material that was taking up tolerances on worn engine parts.So,I am letting sleeping dogs lie for now with that.It is a very quiet engine right now that doesn't leak oil.

crash · Post by **crash** » Sat Jul 07, 2007 4:18 am

check around parts stores in your area gary. the screened egr gasket (non-tomco brand) we carry is called Blue Streak which is actually Standard Motor Products. The part # is VG57

I ran seafoam through my 94 and also through the 93. Made no difference whatsoever. yes, it was entertaining to watch the van smoke out the neighbourhood. other than that. no improvement in performance at all.

My conclusion is... if it's a little rough and always has been, leave it. You can check out my other posts about trying everything... i literally have. cap, rotor, wires, ign coil, ign module, etc etc etc. no improvement at all. it's a minor roughness at idle and it's always had it since I've owned it (3yrs). never smokes or burns oil. still gets great gas mileage (better than my 99). if it was a newly developed roughness thing that would lead me to be concerned and start trying to resolve it. If mine ends up going south... no better excuse to V8 it.

SafariRob · Post by **SafariRob** » Sat Jul 07, 2007 4:27 am

Gary,
Sounds like installing a helicoil is the way to go. But would locktight be needed after doing that?

I've never heard of a heated EGR valve before--what could make them hotter than exhaust gases flowing through them?

GEJ · Post by **GEJ** » Sat Jul 07, 2007 4:21 pm

Rob,I not sure about the heated EGR's.I was told by a NAPA parts guy that has been in the business a long time.He said it was the updated version of EGR's for these Astro's.He said it heated up the EGR faster than a normal EGR would be and therfore didn't need a screen gasket.Maybe it burns off the carbon????.Don't know.He said because of the updated EGR it had been a long time since he sold any screen gaskets.I'll find out more on Monday and let you know.Gary.

BTW:I am talking about loctite on the studs that I am using to replace the bolts after the heli-coil repair.Going to be fun finding metric studs.Don't want to press my luck by heli coil both bolt holes,so I have to stick with metric studs to keep in uniform.

BLAZER · Post by **BLAZER** » Sun Jul 08, 2007 10:56 am

Gary, you got a dremel tool? If so, take a longer threaded metric bolt, put on a nut, then install your helicoil/locktight, then put the bolt in. Maybe let the locktight set up a bit, then cut off the head of the bolt using your dremel cutoff. Now you can take the nut off which in turn fixes any burred up threads from the cut off....that is if you can't find a stud in metric sizes.

Smiliesafari · Post by **Smiliesafari** » Sun Jul 08, 2007 11:08 am

Any of your local Japanese car repair shops should be able to supply you with metric studs. Studs and Locktite would be my choice of a repair method. The studs would eliminate the constant abuse of the threads in the manifold.

GEJ · Post by **GEJ** » Sun Jul 08, 2007 11:10 pm

Thanks all for your replies.I'll let you know how things worked out.Going to try to take care of this on Monday.

Chevy & GMC Vans

Chevy & GMC Vans

EGR Bolt hole repair

EGR Bolt hole repair