Air Intake, Breather Hoses

6.5 Chevy

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Aug 20, 2013
I’m working on getting my 1985 Riviera T-Type 3.8 turbo running after sitting for about 15 years. There is a short hose that runs from the back of the drivers side valve cover to the air intake pipe just before the turbo. This hose is badly deteriorated and has been patched with silicon over the years and is no longer usable. Does anyone have any ideas what to use to replace this hose? I’ll include pictures.

One more question, the oil filler neck has a nipple where a hose should be but I don’t know where the hose is suppose to go. Can anyone help me out here? I’ll get a picture of this and post it later. Thanks!
 

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Here is a picture of the oil filler neck. I know almost nothing about this car’s history but when I got it there was no hose attached here and I can’t find any pictures online that show it.
 

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Do you have a couple expanded pictures of the engine bay ?
 
last year, @Barberman91 was asking about the same breather hose on the valve cover.

https://turbobuick.com/threads/valve-cover-breathers.458461/

unfortunately, he has not logged into the forum in the past 12 months. was about to suggest contacting him to learn what he did as a solution.
Thank you for that link, I didn’t see that post in my searches. Post #18 in that link shows a good picture of the engine bay but you can’t see the back of the oil filler neck where the hose nipple is. Every picture of a 3.8 turbo engine I find online is from the front so I can never see this hose. Not too many of these turbo Riviera’s out there so info is scarce.

Thank you guys both for responding!
 
On your turbo Riv, someone has installed the oil fill tube with the built-in breather that was used on the 84-85 turbo regals. the turbo Riv's factory crankcase breather was via the hole in the rear of the driver's side valve cover and that rubber tube you are trying to find a replacement for.

you're not finding an unused, available, open port on the intake tubing for the 84-85 oil fill breather to connect with as the intake plumbing for the 84-85 turbo regals was slightly different. look up some 84-85 turbo regals for sale with tons of pics (hemmings, etc) to see for yourself.

the turbo Riv used the shorter oil fill tube and cap found on the 86-87 turbo regals.


refer to the engine bay pic in that link I posted above AND check out this turbo Riv on hemmings to see the shorter oil fill tube.

https://www.hemmings.com/classifieds/dealer/buick/riviera/2144139.html


it can get very confusing as both the 84-85 turbo regals and turbo Riv's used the engine SPID of LM9. there are subtle differences though how stuff works. there were less than 50 turbo riv's in 1985, as reported.
 
On your turbo Riv, someone has installed the oil fill tube with the built-in breather that was used on the 84-85 turbo regals. the turbo Riv's factory crankcase breather was via the hole in the rear of the driver's side valve cover and that rubber tube you are trying to find a replacement for.

you're not finding an unused, available, open port on the intake tubing for the 84-85 oil fill breather to connect with as the intake plumbing for the 84-85 turbo regals was slightly different. look up some 84-85 turbo regals for sale with tons of pics (hemmings, etc) to see for yourself.

the turbo Riv used the shorter oil fill tube and cap found on the 86-87 turbo regals.


refer to the engine bay pic in that link I posted above AND check out this turbo Riv on hemmings to see the shorter oil fill tube.

https://www.hemmings.com/classifieds/dealer/buick/riviera/2144139.html


it can get very confusing as both the 84-85 turbo regals and turbo Riv's used the engine SPID of LM9. there are subtle differences though how stuff works. there were less than 50 turbo riv's in 1985, as reported.
Very good info, thanks! I can’t imagine why my car has the Regal oil filler neck. I’ll have to check my parts car (also an 85 turbo Riv) and see what it has. Thanks again, man. I’m getting closer to figuring this car out and finally getting it to run.

Now I’m wondering if I can cap off the hole on the valve cover somehow and run a hose from the oil filler neck to the air intake tube. Do you have any insight whether that would work or not? I’ll start looking at pictures of the Regals and see what they look like.
 
I'd cap off that oil filler tube and put a breather in the valve cover and let it vent. Your just blowing oil through the intake system with it hooked up. The valve cover hole rubber grommet is probably the same size as the 86-87 turbo regal, so you could use a grommet and small aftermarket breather for the right side valve cover like the one used on those cars.
 
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...Now I’m wondering if I can cap off the hole on the valve cover somehow and run a hose from the oil filler neck to the air intake tube. Do you have any insight whether that would work or not? I’ll start looking at pictures of the Regals and see what they look like.


you have plenty of options to entertain...

that original rubber tube from valve cover to intake air plumbing was just a breather for crankcase emissions. As @WE2Regal noted above, many owners of the 86-87 turbo regals install a push-in type breather and rubber cap to eliminate the factory system pulling oily air. take a look at your throttle blade. i'm sure it's covered in a black oily film. suggest disassembly of the air intake tubing and cleaning with a hot water soapy solution and some simple green or equivalvent. no solvent based cleaners on the plastic. clean the throttle plate and throttle body with a throttle body cleaner. may also spray down the screens in the MAF sensor while it is apart. use a maf sensor cleaner on the maf. there are combo kits of CRC brand throttle body cleaner and maf sensor cleaner at Wal-Mart's auto section. best bang for the buck.

----install the oil fill tube and cap used on the 86-87 turbo regals and originally on your turbo Riv. maybe the parts car has one? if not, post in the parts wanted. plenty of guys have taken them off and use a fill tube with a breather like those from metco motorsports. if the hole in the rear of the DS valve cover looks to be the same size as the hole in the 86-87 PS valve cover, you can do as noted above, grommet & breather & cap. you'll probably need a new oil fill tube gasket in any case. the ones from highway stars have a tapered top edge like the original for the purists while the one from Kirban's is just a square edged seal, slightly smaller in diameter that the metal washer. ideas, choices below...

https://www.ebay.com/sch/highway_stars/m.html?_nkw=&_armrs=1&_ipg=&_from=

https://www.kirbanperformance.com/product/243/Passengers+Side+BREATHER+BY-PASS+KIT+#1580.html

https://www.kirbanperformance.com/product/135/PASSENGER'S+SIDE+VALVE+COVER+GROMMET+#6982.html

https://www.mcmaster.com/rubber-caps

----sure, use the 84-85 turbo regal oil fill tube and install a hose between the breather cap and the port on the intake hose. still have to do something with the hole on the rear of valve cover...

if you are not in CA - having to deal with their smog inspections - then it may be easiest to use the correct oil fill tube, install an open element breather and new grommet on the valve cover, and install a rubber cap secured with a zip tie on the air intake hose. i added the mcmaster link for the rubber caps as in a few years, the cap supplied with the breather will begin to crack (dry rot and function of under hood temps).

depending on which crankcase vent filter you buy, you may have to cut some material off the end of the tube that will insert into the valve cover. don't know if that valve cover has an internal baffle in place like the 86-87 and/or the proximity to the valvetrain components once installed.
 
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