coolant bypass tube???

[HotZ28]

Great info on this thread. Since I'm not sure what series I have ('93 PAU) like I or II, I may need to check out that elbow, for a car this old.
I suppose if the LIM gasket etc should need fixing, the elbow would need replacing also ??

The 1993 Series I engine does not use the plastic elbow(s) mentioned (shown) in this thread. However, it did come with a plastic threaded hose nipple with an attached rubber hose, which were also problematic.

The replacement metal hose fitting for the Series I engine, can be found at most national part stores in several brands, like Dorman, Help, or Motormite and comes with 5/8" hose x 1"-14 thread. All three of these aftermarket fittings use the same Part #56359 and are available for less than 5 bucks. Of course, if you prefer, most GM dealers would have a replacement metal fitting, Part #25535749 for 15-18 bucks. Keep in mind; this fitting is only for the VIN-L 3800 engine and not for the 96 up VIN-K 3800 Series II. The VIN-L engine came installed in Buick, Olds and Pontiac, in various body platforms.

For removal of the fitting, (if you don’t have a large thread extractor), you can use a flat chisel about the same size as the I.D. of the hose nipple. The cutting end of the chisel is tapered and should go up into the threaded piece about 1/2 in. You will need to bump it in with a hammer far enough, to get a grip on the fitting. Once the chisel is snug, use a crescent wrench to turn the chisel “counterclockwise” and that will loosen the fitting. (It should start coming out). If the chisel slips on the first try, tap it in a little further, then try again.

In addition, you have several options for the bypass hose; Goodyear Part # 63043, Kelly Springfield Part # S-3041, DAYCO Part # 71624, GATES Part # 18801 {5/8" x 7 1/2" Cut to fit) Price range on the bypass hose ranges between 6 and 15 bucks, depending on brand selected. Replacing the hose clamps is optional, if not damaged.

Metal fitting:

Hose:

 

[HotZ28]

I meant to ask, HotZ28, when you say it's a good to replace the idlers, do you mean the bearings of the tensioner pulley? Are those the "idlers"? Thanks.

The idler is a one piece unit that includes bearings.

Plastic Pulley:

Metal Pulley:

 

[stachman]

Thanks HotZ28 for the idler info. The one that is on there seems pretty clean and free running...I will give it some thought while it is accessible.

Here is an update. I found the one more bolt holding the tensioner on, and then after about 1/2 hour of pulling and rotating the tensioner on the lower metal coolant port, I finally got the tensioner off. It was difficult. I was trying not to be too hard on the seating surfaces of the metal port, and also it was tough to reach down and pull sideways with very little clearance to work.

The plasticnelbow was very deteriorated. When the tensioner slid off, and the elbow pulled out of the manifold, the elbow's Oring and everything beyond the Oring stayed in the manifold. Same thing happened when I pulled the elbow out of the tensioner.

Seems like the plastic elbow can't stand up to the task and is a very weak link. The designers probably painted themselves into a corner (tolerances etc) in other related parts of the engine design and that's how they ended up with this elbow. If they had gone with a metal elbow like plano_doug pointed out, that would have probably accomplished everything they needed in terms of tolerances and thermal expansion etc, but with better lifetime, and also easier to remove and service.

Anyway, the Orings came out easily from the manifold and tensioner, but now the hard plastic ends of the elbow are still in there and very stubborn.

Also, the elbow I removed had black Orings, and the lower metal port on the tensioner had a black Oring, but it looks like there is still residue from orange Orings in both ports of the tensioner and the one in the manifold, so I'm thinking that means the elbow was replaced at least once before. The new Orings on the OEM GM elbow and the GM Oring for the metal port are all orange - so maybe the orange residue is from the factory original Orings.

I am thinking about using a plastic scraper to remove the ancient orange Oring residue from inside the various port to have a nice clearpn seating surface for the new Orings. Hopefully I can avoid scratching the seating surfaces. Does that sound like a good/necessary idea?

To remove the ends of the old elbow, I have read that people like using a bent-tip awl, but I'm not sure I believe that will be stiff enough to pull hard enough on the stuck plastic which is baked and lodged in there. Im also comcerned that the tip of the awl could scratch the Oring seating surface.

I'm thinking I will try the following:
Maybe use some penetrant like wd40 and then clean that off thoroughly so the wd40 won't attack the new elbow/Orings?
Use a tapered thread-tapping tool of a size which will easily go into the inside diameter of the stuck plastic ring-ends from the old elbow and then carefully cut thread for itself into those stuck plastic ring-ends. Try not to create too much loose debris from cutting threads into the plastic. Don't thread in so far that the tap starts contacting the metal seating surfaces. When the tap has a satisfactory bite on the plastic, pull and rock a little. Does that sound like it will work? Anyone have a better option? Those plastic elbow ends are a bear.

By the way, the amount of coolant that drained was less than I thought it would be, maybe a quart. That was easy to catch, no mess.

Thanks again everybody, particularly HotZ28, you have clearly done quite well navigating down these paths before. Cheers!

 

[pila80]

Thanks a bunch for the series I info hotz28 !!😀 All I have to do now is get the wife to let me have it for a while, to fix some of this stuff !

Bill

 

[stachman]

I successfully extracted the broken-off end parts of the elbow from the tensioner and from the manifold - I made my own tool from a wire hanger, two rounded fingers that reach through the broken end-ring and then pull together on the ring on opposite sides. and no scratches on the seating surfaces of the interior walls, since the tool I made had rounded shape where it touched the walls.

So now I have to decide, how clean do those interior surfaces need to be where the new Orings will contact them? As I mentioned in my previous post, there is residue from previous orange OEM Orings still baked on there. It feels smooth to the touch, but I am uncertain as to whether it is smooth and clean enough. I tried scraping the orange residue with a wooden chopstick and it wouldn't come off. I guess that is why the previous mechanic left it there.

I'm thinking maybe I should just go full speed ahead and reassemble with the new elbow and Orings and test the new seals... If it leaks and i have to go back in, it would be much easier to disassemble again now that I know what I'm doing and all parts and joints are new / clean.

One other thing I noticed was that the black Orings I took off had some of the orange material from the even older Orings baked onto them, so if there is still orangemresidue on there which will contact the new Orings, maybe under heated conditions the new and old Oring material play well together and combine to seal...?

Am I being overly cautious about the seating surfaces for the Orings? Thanks everyone for your thoughts.

 

[trlbzrss]

IIRC the prefered method of cleaning the bore is with some real fine steel wool or that's what I used. I folded the wool around a small magnet and it worked just fine. Since the o-ring seal isn't too far in you can clean more towards the outside and lessen the chance of getting a lot inside the engine.

 

[HotZ28]

Go to Home Depot, or your local hardware store and get a "tubing cleaner brush". IIRC, the one I use is for 3/4" dia. I.D. (inside pipe) This type of brush is typically used to remove tarnish from copper pipe before soldering. The brush works like a charm on copper & aluminum. Click Here

 

[stachman]

Thanks guys! I ended up cutting a narrow strip of scotchbrite pad and working it around with my finger in all the female ports. There was still some visible orange residue on the from the older/original Oring but I couldn't feel it by touch at all (i remember from my machining days that i can feel about a thousandth or a few thousandths 🙂 so I decided to go forward and reassemble, which went pretty smooth except a challenge of getting the metal port and the elbow fitted into the manifold at the same time. I wetted all the Orings with coolant before starting the reassemble but the Oring on the metal port was a tight fit. I had to go back and forth using a plastic hammer tapping a piece of soft wood against the tensioner by the metal port, and then on the elbow, and back again. The elbow surprised me and still had a little more distance left to go when the metal port and tensioner were already fully installed, but the elbow popped into a good square fit with a little more encouragement.

Refilled the coolant, and ran the engine up to operating temp. No leaks!

Thanks again guys for your help and encouragement! It was great working with you! I'm sure we will met again as I try to keep this old 96 PA ticking. Cheers!

HotZ28, I added that tubing brush to my Home Depot list. I will check it out next time I go there, will probably pick one up for my toolbox. I decided to leave the idler alone for now - if there is a certain sound or indication of failure coming, please let me know. Thanks for all your info and pictures, you were fantastic!
Plano_doug, thank you too! It's interesting that the elbow in metal form is out there. I might look that up to find out cost.
Trlbzrss, thanks for the steel wool idea.