Tensioner Assembly Removal for SII 3800 Engine and Bypass Elbows '99 and Up


BNaylor
08-01-2008, 09:33 AM
This procedure may come in handy to remove the main serpentine drive belt tensioner assembly. Also, it is highly recommended to remove the tensioner to replace the pulley or install a new tensioner assembly which should come with the pulley. Further, tensioner removal is required when replacing lower intake manifold gaskets.

Note: Make sure engine is cool. Disconnect battery negative cable before starting work.

1) Sufficiently drain coolant.
2) Remove serpentine drive belt. Use a 15mm socket on the tensioner pulley bolt and turn counterclockwise to loosen belt. Note: For clearance to get to the tensioner pulley bolt on GM cars that have the coolant reservoir located on the right strut tower remove the coolant reservoir first.
3) Remove alternator. Use 15mm short and deep sockets on mounting bolts.
4) Remove heater hoses from tensioner fittings. <-- Or you can leave them connected if doing just a LIM job.
5) Remove tensioner retaining bolts. Total 3 bolts 15mm socket size. See pic.
6) Remove tensioner from engine. Note: While removing tensioner you will be removing the large 90 degree plastic elbow that connects to the lower intake manifold and at the same time the shorter 90 degree elbow to the water pump. You may have to pry or pull hard on the tensioner to get it off.
7) Installation is reverse.
8) Use new o-rings on the elbows. GM/Delco elbows will have the two o-rings. See pic. Inspect elbows for cracks or damage. Replace, if necessary. In most cases the ends of each elbow will break off during tensioner removal requiring replacement. See pic at this post (http://www.automotiveforums.com/vbulletin/showpost.php?p=5814523&postcount=2).
9) Torque tensioner bolts to 37 ft-lbs.

NOTE: Applicable to all '99 and up GM cars equipped with the L36 or L67 SII 3800 engine.


Elbow to lower intake manifold (LIM) - GM Part # 24503423
Elbow to water pump - GM Part # 12565082

http://i5.photobucket.com/albums/y186/lizzywiz/DSC02589.jpg



Tensioner bolt location. Total 3 shown by red arrow and circles. Use 15mm socket.

http://i5.photobucket.com/albums/y186/lizzywiz/tensioner.jpg

BNaylor
09-07-2008, 02:26 PM
Pics of coolant bypass elbows after tensioner is removed. Not too fun picking out the broken plastic pieces out of the water pump and LIM outlet ports. :grinno:


http://i5.photobucket.com/albums/y186/lizzywiz/DSC02604.jpg

happydog500
01-01-2010, 05:19 PM
Thanks BNaylor,

I love when people post pictures.

Chris.

Patiodadio
01-15-2010, 08:38 PM
WOW!!! Am I glad that I found this info. I have a 2001 Buick Lasabre, and the antifreeze has been slowly disappearing from the resevoir for five years, but it got a whole lot worse in just the last two weeks. The antifreeze would "pool up" under the removable engine plastic cover right at the front edge of the black intake cover where there is a metal "pocket". I also noticed antifreeze near the tensioner on a ledge, but couldn't figure out how the antifreeze could get from that area to the front "pocket". In hindsight, it must be some kind of airflow.

In any case, the problem was exactly what is shown earlier in this thread. The two 90 degree "pipes" came in a kit and cost less than $4.00. The big "stovepipe" had a bad end where it went into the main block. I am so pleased that this was an easy 2 hour fix. No heads to pull, WONDERFUL!!! The only part that was a bit frustrating was draining the antifreeze out. I had to use a long socket with a pipe taped to it to unscrew the drain plug and recover the antifreeze. I suppose it might be argued to change the antifreeze too, but I had gone through a gallon already, and the recovered amount looked clean.

Many thanks to all, and I needed to leave that message here!http://www.automotiveforums.com/vbulletin/images/icons/icon7.gif

Patiodadio
01-16-2010, 11:16 AM
WOW!!! Am I glad that I found this info. I have a 2001 Buick Lasabre, and the antifreeze has been slowly disappearing from the resevoir for five years, but it got a whole lot worse in just the last two weeks. The antifreeze would "pool up" under the removable engine plastic cover right at the front edge of the black intake cover where there is a metal "pocket". I also noticed antifreeze near the tensioner on a ledge, but couldn't figure out how the antifreeze could get from that area to the front "pocket". In hindsight, it must be some kind of airflow.

In any case, the problem was exactly what is shown earlier in this thread. The two 90 degree "pipes" came in a kit and cost less than $4.00. The big "stovepipe" had a bad end where it went into the main block. I am so pleased that this was an easy 2 hour fix. No heads to pull, WONDERFUL!!! The only part that was a bit frustrating was draining the antifreeze out. I had to use a long socket with a pipe taped to it to unscrew the drain plug and recover the antifreeze. I suppose it might be argued to change the antifreeze too, but I had gone through a gallon already, and the recovered amount looked clean.

Many thanks to all, and I needed to leave that message here!http://www.automotiveforums.com/vbulletin/images/icons/icon7.gif

Update: The leak from the "stove pipe" is fixed, but I am still getting a bit of antifreeze in the "pocket" as described above. I have a CD ordered from Ebay that issupposed to give me all details to find out what is connected to what there. Update to follow...

Samples08
02-23-2011, 03:49 PM
Thanks you so much for this infromation i needed it badly :grinno: ive been trying to figure this thing out for three days now i can finally save on anti freeze:banghead:

porterico
10-28-2011, 08:40 PM
Awesome information.

I had a bad radiator, replaced it... but was still losing coolant
water pump went out... figured that was the problem... replaced it... but still losing coolant

Problem started getting serious using 1 gallon of water / coolant every 20 miles or so... could not find the leak...

Then it just started looking wet around this area in question, couple days later it was spraying out... on the verge of failure.

It was really easy to take apart... the elbows are fairly melted into the tensioner assembly unfortunatley... it will take a bit of work to clean up the assembly, but yea... a few dollar fix makes this totally worth it. I will update to let yall know if this finally solves my cooling system issues once and for all...

Tech II
10-29-2011, 08:09 AM
I NEVER just replace the o-rings....I always replace the elbows and o-rings.....even though the lower one rarely leaks......on the opposite side of the engine, under the throttle body, that leak is usually the throttle body gasket.....

porterico
10-29-2011, 04:06 PM
is there any need to use some kind of sealant when installing the elbows?

HotZ28
11-14-2011, 12:42 PM
NOTE: Do not use the DORMAN elbow kits, the O-rings are too small and will soon start leaking. Use only GM part numbers shown in the first post. BTW, when using the GM fittings/o-rings, there is no need to use any type of sealant, but it helps to spray the o-rings with silicone before installing.

enslow
11-14-2011, 12:50 PM
When I did my LIM gaskets, I followed advice elsewhere to use Help! elbows with a skim coat of RTV. I guess if they leak in the future, I'll have to replace them with GM, and spend some fun time removing RTV. If only I knew.....

porterico
11-14-2011, 03:08 PM
I replaced using the dorman kit which was like $4 at Oreilly, and didn't use sealant. I torqued the bolts to the specified torque and had no leaking at all. The car got totalled about a week after I replaced the elbows, so I won't be able to find out if they leak soon after install. Thanks again for the great thread.

HotZ28
11-14-2011, 11:26 PM
The leak with the DORMAN fittings/O-rings will start with the weather change, expansion/contraction in cold weather.

jennet89
08-23-2012, 12:17 AM
3800 Performance offers high performance aftermarket car parts and modifications for your 3800 Series II and 3800 Series III Pontiac and gives you the complete satisfaction.
3800 series engine parts (http://www.wbodystore.com/9-3800-series-engine-parts)

edwinn
08-24-2012, 10:04 AM
Yes, very interesting topic!!

Last summer I had a BAD experience with the serpentine belt tensioner. It was getting very NOISY.. screeching actually. Was about to get the "pulley" replaced but put it off for two weeks. An appointment was made, however 1-1/2 days before the service visit, the tensioner bearing FAILED (froze up) and the belt came off. It was so frozen, I couldn't turn the pulley by hand at all. See photo below.

Here is a photo of the FAILED bearing. The pulley is cocked sideways.

http://home.comcast.net/%7Eedwinn/IMG_0251_0712.jpg


A replacement pulley bearing wasn't expensive at all, and you'd be surprised how much QUIETER the engine was with a new one. It was like a new engine!

What also helped was a high-tech Goodyear Gator belt which runs quiet and resists cracking on the inside ridges.


Below is the NEW tensioner bearing and belt installed.

Again I couldn't believe how QUIET the engine idled after this fix!!!

http://home.comcast.net/%7Eedwinn/IMG_0257_0714.jpg

Should have had that item replaced a LONG time ago.. or at least two weeks sooner. :banghead:


Notice the variable "block width" on the belt.. it's like low-noise tire technology. Lol

In this case I recommend ditching the OE belt.


-Ed

jamyers
10-01-2012, 02:22 PM
Anybody have any experience with the new Dorman aluminum elbows, p/n 47065HP? Looks like www.rockauto.com (http://www.rockauto.com) is the only place to get them currently.

I'm thinking of getting these and using the GM o-rings, hopefully it'll be the LAST time I do this.
http://www.rockauto.com/getimage/getimage.php?imagekey=3887103&imageurl=http%3A//www.rockauto.com/info/RB/47065HP-007.jpg

happydog500
10-01-2012, 07:03 PM
Thanks for letting us know about these.

Since mine lasted 150,000 miles plus, and another one thousands without any problems, I'll stick with the stock ones. I would use them if I was redoing it tho.
When I took mine out to do the rebuild, seems like it would be hard to get them out if they didn't break, since they break because they can't come out at the angle there in at.

Chris.

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