coolant bypass tube???

[lavecchia]

I have a 96 park ave and there is a 90 degree tube that go from the intake manifold to I think some part of the belt tensioner? and it is leaking does any one know who to change it?

 

[Cadillac_AL]

That;s the Buick 3.8 booby trap. GM put a plastic elbow in there for the coolant to go through (and to save a couple pennys). We all know if it's made of plastic it's made to break. The replacement should be a metal one; mine was. Don't accept another plastic one.

 

[HotZ28]

Al, I do not know of anyone who offers a metal replacement elbow for the 1996 Series II Vin-K bypass, which is a totally different design from the Series I Vin-L plastic nipple. Dorman does offer replacement plastic elbows, but some who have used them complain of the O-rings being too small, which allows coolant leaks when cold. I recently replaced my tensioner and installed a new OEM elbow (with O-rings) from the dealer and all is well. For more discussion on this subject, Click Here BTW, the tensioner has to be removed to replace the elbow.

 

[Cadillac_AL]

Al, I do not know of anyone who offers a metal replacement elbow for the 1996 Series II Vin-K bypass, which is a totally different design from the Series I Vin-L plastic nipple. Dorman does offer replacement plastic elbows, but some who have used them complain of the O-rings being too small, which allows coolant leaks when cold. I recently replaced my tensioner and installed a new OEM elbow (with O-rings) from the dealer and all is well. For more discussion on this subject, Click Here BTW, the tensioner has to be removed to replace the elbow.

Well that's a bummer. I would have thought GM would have learned their lesson after the series I failures. I guess it's just considered another wear item now. I would hate to have that crack on me while i was on vacation away from home. Oh well, I guess every vehicle has to have a weak link somewhere.

 

[lavecchia]

does anyone have the GM part numbers??

 

[HotZ28]

The plastic elbow is called a "pipe assembly" by GM, Part #24503423. List for less than 15-bucks @ the dealer, but if you have time, you may want to order one from Rightnowautoparts for $8.89 plus shipping; either way, they are cheap! I forgot to mention, disconnect the negative battery cable & remove the alternator, in addition to the tensioner for better access.

 

[plano-doug]

The plastic elbow is called a "pipe assembly" by GM, Part #24503423. List for less than 15-bucks @ the dealer, but if you have time, you may want to order one from Rightnowautoparts for $8.89 plus shipping; either way, they are cheap! I forgot to mention, disconnect the negative battery cable & remove the alternator, in addition to the tensioner for better access.

I know this is an old thread, but wanted to add, for anyone else like me who stumbles on to this, that there is a second GM part number that goes with p/n 24503423. That is just the upper elbow; the lower elbow is GM p/n 12565082.

Also, I found this Youtube video that was useful. [ame]http://www.youtube.com/watch?v=ZX__c6HZuCQ[/ame] They do a couple things I'd do differently, but it's still worth a look. I would not have left the oil cap off while they were working on the motor. There's no sense in risking getting dirt and debris in there. Also, they left the alternator attached to the tensioner during the repair. I expect that added weight can potentially impart damaging stress to the elbows while you're trying to get the tensioner and elbows into position.

Doug...making my first post here...

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[plano-doug]

The plastic elbow is called a "pipe assembly" by GM, Part #24503423. List for less than 15-bucks @ the dealer, but if you have time, you may want to order one from Rightnowautoparts for $8.89 plus shipping; either way, they are cheap! I forgot to mention, disconnect the negative battery cable & remove the alternator, in addition to the tensioner for better access.

I know this is an old thread, but wanted to add, for anyone else like me who stumbles on to this, that there is a second GM part number that goes with p/n 24503423. That is just the upper elbow; the lower elbow is GM p/n 12565082.

Also, I found this Youtube video that was useful. [ame]http://www.youtube.com/watch?v=ZX__c6HZuCQ[/ame] They do a couple things I'd do differently, but it's still worth a look. I would not have left the oil cap off while they were working on the motor. There's no sense in risking getting dirt and debris in there. Also, they left the alternator attached to the tensioner during the repair. I expect that added weight can potentially impart damaging stress to the elbows while you're trying to get the tensioner and elbows into position.

Doug...making my first post here...

.

 

[mikeske11]

When I had my engine and transmission resealed last month my mechanic replaced the elbows along with all the hoses on my 1998 Park Avenue. It was fairly easy for my mechanic to do this as they dropped the entire engine cradle out of the car and then everything that required or should be replaced was. It was costly to reseal the engine and transmission but after a month no leaks and with the in my garage I am really really glad I had the work performed. My mechanic also did a major tuneup and replaced the EGR and O2 sensors along with the mass airflow sensor.

I was basically doing a complete 90,000 mile PM along with the catching any thing that could go wrong done. My mechanic also discovered the rack and pinion was also leaking and it was also replaced.

 

[HotZ28]

I know this is an old thread, but wanted to add, for anyone else like me who stumbles on to this, that there is a second GM part number that goes with p/n 24503423. That is just the upper elbow; the lower elbow is GM p/n 12565082.

Doug...making my first post here...

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Welcome to the forum Doug and thanks for posting. However, for the benefit of others, we need to make it clear that this thread was originally discussing the coolant elbow for an 1996 PA which does not use the lower plastic elbow. This would also include 1995-1998 VIN-K & VIN-1 engines. IIRC, the lower elbow Part # 12565082 was not included until 1999.

 

[plano-doug]

Welcome to the forum Doug and thanks for posting. However, for the benefit of others, we need to make it clear that this thread was originally discussing the coolant elbow for an 1996 PA which does not use the lower plastic elbow. This would also include 1995-1998 VIN-K & VIN-1 engines. IIRC, the lower elbow Part # 12565082 was not included until 1999.

Thanks for the clarification, HotZ28. Good point.

FWIW, mine is indeed a 99 (Lumina). I did see mention somewhere about the change in the lower section. (In researching this little project, I've read too many threads on too many forums to be sure where I saw it 🙂)

Also, I did find some metal elbows from Dorman. But based I what I've read, I'm leery of using the Dormans for this project. Plus, my personal experience with Dorman is that they're kinda hit-or-miss anyway. If one of their window switches craps out, I won't lose a motor, but I'd rather not try them under the hood unless there's no other choice.

Lastly, I can't find see any edit/delete options; otherwise I'd'a whacked my duplicate post already. Sorry about that.

Doug

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[HotZ28]

Thanks for the feedback Doug. Don't worry about the duplicate post, the edit function has a time-out feature for some unfortunate reason. I wish this flaw could be eliminated, so we all could edit/delete our older post. Most of us will have some afterthoughts on our post, or duplicate post that need to be edited after the time-out. Anyway, where did you find the "metal elbows from Dorman"? Many of us have discussed the advantage of using metal vs plastic for this application and why GM has never recognized this as an improvement, or option. If you could post a link, of just give us a hint to where you found the metal elbows, it would be appreciated. BTW, I don't remember where, but I did a post discussing the difference between OEM elbows/o-rings and Dorman. The best I can remember, the Dorman elbow is nearly identical in dimensions, but the o-rings were made of a different material and slightly different size. If Dorman is actually furnishing metal elbows, we can get the o-rings from GM and hopefully eliminate this problem altogether.

 

[plano-doug]

Anyway, where did you find the "metal elbows from Dorman"? Many of us have discussed the advantage of using metal vs plastic for this application and why GM has never recognized this as an improvement, or option. If you could post a link, of just give us a hint to where you found the metal elbows, it would be appreciated.

Hi, HotZ28. I found them at Rockauto under:

1999 CHEVROLET LUMINA 3.8L V6 OHV : Heat & Air Conditioning : Heater Hose Fitting

http://www.rockauto.com/catalog/moreinfo.php?pk=3887103

They're listed as being compatible with a myriad of GM platforms.

BTW, I don't remember where, but I did a post discussing the difference between OEM elbows/o-rings and Dorman. The best I can remember, the Dorman elbow is nearly identical in dimensions, but the o-rings were made of a different material and slightly different size.

I do recall reading that!

HTH.

BTW, the car's been running great all weekend. I took it out a couple times to burp the radiator and top it off, then turned it back over to my 17yo daughter. Hopefully, she'll keep it between the ditches and the shiny side up 😀

Doug

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[stachman]

Hello HotZ28 and Plano-Doug and everyone on this thread,

Thanks everyone for your thoughts and information. I just discovered today that I need to replace the elbow on my 1996 Park Avenue.

From reading other webpages, I thought that there was an upper and lower elbows on my car which I couldn't see but I assumed that it was down there somewhere. I can clearly see the elbow which has 2 equal length arms which is the same part used as an "upper elbow" on other models/years.

I want to ask, doesn't there have to be another port on the tensioner housing? And is that flexible? If there was only one hose connection, the coolant could not get both In and Out of the tensioner housing.

I want to know what to expect in advance of getting in there, so I don't break something off if it's is a stiff connection.

Doug, it sounds like you had a good idea for removing the alternator first,mand then removing the tensioner, to minimize the handled weight while positioning the elbow in there so as to not damage it.

When I remove the serpentine belt, do I put a socket right on the tensioner bolt head which is also through the center of e tensioner pulley? And the tensioner is spring loaded I think right? Push the wrench counterclockwise to slacken and remove the belt, and slowly release the wrench clockwise to allow the springs in the tensioner to increase tension on the belt - is that correct too?

Thanks everyone for your help. This is my first experience with the serpentine. I have done a lot of other work on my old 1996 PA and the 3800 continues to have a great long life.

 

[plano-doug]

I want to ask, doesn't there have to be another port on the tensioner housing?

Yes, the coolant has to go somewhere 🙂 I've seen a pic - danged if I can find a good one now - showing the different setup that uses only the one elbow. But, yes, the coolant does indeed circulate thru the tensioner housing. I'm sure others here who've dealt with the single-elbow version of the motor can elaborate on this.

When I remove the serpentine belt, do I put a socket right on the tensioner bolt head which is also through the center of the tensioner pulley? And the tensioner is spring loaded I think right? Push the wrench counterclockwise to slacken and remove the belt, and slowly release the wrench clockwise to allow the springs in the tensioner to increase tension on the belt - is that correct too?

Off the top of my head, I can't recall which way to turn it, but you'll be able to tell with no problem. To swing the tensioner arm, you insert a 3/8" socket driver into the square hole on the tensioner. Don't put a socket on the bolt.

I use one of these style socket handles:

It doesn't take a lot of torque, so a cheater pipe isn't needed.

HTH.

Doug

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[HotZ28]

As mentioned, the lower "plastic" elbow is not used in the 1996 engine, it is built into the aluminum tensioner. You would need an O-ring Part # 24502846 Item # 13 in this diagram to replace the existing one. You are correct on the removal of the serpentine belt. This would also be a good time to check/replace idlers while you are at it. Just remember, the idler bolts are a left hand thread and you turn the bolt clockwise to remove.

 

[HotZ28]

Here is a pic of the tensioner used on the 1996 PA. (Two different views)

 

[stachman]

You two guys are great! Thanks for the awesome stuff.

So I just came back in from starting the job. I got the belt off the pulleys, and removed the alternator, and I could see that metal port of the cast tensioner housing going into the side of the engine (block? head? It's dirty 🙂. Of course I can also see the two hoses which go to the heater core in the passenger compartment. So those plus the elbow makes four total coolant ports on the tensioner housing.

At least one of the alternator bolts also went through the tensioner, and then I found one bolt so far which only holds the tensioner on. The tensioner is still tightly held in place so I think there must be at least one more bolt to find, plus the stiffness of the metal port with its O-ring going into the engine (perhaps hasnt been budged since the factory) plus whatever stiffness comes from the plastic elbow.

I can wiggle the elbow a little so I think I need to focus on the other attach points: first I will study HotZ28's pictures (thank you!) of the tensioner to see if any other bolts are still hidden and remove those. Then I think I should wiggle/rotate the tensioner around the metal port's axis to see if I can back that out and protect that metal port and its seating surfaces, while allowing the elbow to flex a bit. I think at some point the metal port will pull out and I expect to get a gush of coolant (catch pan is ready).

Does this all sound like I am on the right track? Thanks again guys! I will let you know how it goes.

One more thought - I need to go back and pick up the O-ring for the metal port. So far I bought the elbows (only need one) as GM parts at a GM dealership. Would have been nice as a courtesy if they could have looked at the assembly drawings for the 96 PA and coached me toward one elbow and one O-ring instead of two elbows.

 

[stachman]

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.

By the way, I like your cars, both of them. That is a sharp Ultra you have. Ours is a base model with leather, well used and cared for, and a comfortable ride.

I hope this elbow&O-ring replacement ends up zeroing out the slight coolant consumption which the car has had for a few years and which just got worse when the weather turned cold, with the steady obvious dripping at the elbow today.

 

[pila80]

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 ??