1988 - 1998 (GMT400) Section for all discussion related to the 1987-1998 Chevrolet and GMC trucks.

Drivers side valve cover. Pipe to throttle body. Where to buy the elbow fitting?

Old Mar 6, 2023 | 9:23 PM
  #1  
777funk's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2023
Posts: 3
Likes: 0
Default Drivers side valve cover. Pipe to throttle body. Where to buy the elbow fitting?

Why do both valve covers have a pipe going to the intake (throttle body in my case)? One has an actual valve and one is direct. What's the deal with that? Why are there two breathers to begin with (shouldn't one be enough to relieve blow by pressure) and why do not both have a valve (only the passenger side)?

Secondly, the elbow is broken off of the drivers side valve cover, how do I get what's left of it out of there and where do I find a replacement?
Reply
Old Mar 8, 2023 | 7:44 AM
  #2  
777funk's Avatar
Thread Starter
CF Beginner
 
Joined: Mar 2023
Posts: 3
Likes: 0
Default

To answer my own question, the driver's side valve cover has a breather and the passenger a PCV valve. I just bought the original style grommet (aftermarket Dorman 42332) which can be found on Amazon or Ebay and I bought a 1/2" barb to 1/4" NPT male elbow. I will just thread the elbow into the grommet and run a 1/2" ID fuel hose from the valve cover to the throttle body where the hose originally ran. I also bought a new PCV valve.

Now as to why a breather and a PCV... I still don't know that.

I will also add that the old grommet was so dry rotted that it just broke and it and the original fitting fell into the valve cover. It didn't go into the engine because inside the valve cover is a small "baffle" which caught the broken pieces. Unfortunately in order to get the pieces out, I had to gut the baffle of it's several folds of sheet metal. I'm still going to try to use it however. It still does have the surround, just no more guts inside the baffle.
Reply
Old Mar 9, 2023 | 11:55 AM
  #3  
Gumby22's Avatar
CF Veteran
10 Year Member
 
Joined: May 2011
Posts: 1,578
Likes: 302
From: Central Iowa
Default

To the extent of my knowledge, the stock style breather hose for these trucks hasn’t been readily available for years. There are aftermarket options but they are typically for performance purposes and won’t fit a stock engine. Every time I service one of these trucks and break the tube, I have to use brass fittings and fuel hose to replace it.

The PCV valve and breather systems are designed to work together to manage blow by. Under normal conditions, fresh air flows into the crankcase via the breather tube and the blow by gases are removed through the PCV valve.




The idea is to create a continuous flow of air through the crankcase to remove blow by and moisture.

It also regulates the amount of pressure in the crankcase in order to prevent gaskets and seals from leaking. If the PCV valve clogs up, the blow by gases can still escape the crankcase via the breather tube.

As for the now missing baffles in your valve cover, purchase some stainless steel pot scrubbers and stuff at least one into the valve cover through the breather port. It’ll help to pull/stretch it out. The point of the baffles is to slow down the flow of gases and give the oil mist time to separate. Using the pot scrubbers as a filter media will help accomplish the same thing.

The above image was found at this website with more in depth information about the PCV system -

https://www.aa1car.com/library/pcv.htm
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
nf123
Equinox & Terrain
3
Nov 10, 2020 5:45 PM
Baxterbrandon
Sonic (Aveo)
1
Apr 30, 2018 9:03 PM
holyspatulaboy
Silverado, Sierra & Fullsize Pick-ups
13
Oct 11, 2013 1:53 PM
jft7032
Cavalier
0
Dec 31, 2011 8:43 AM
chase050505
Silverado, Sierra & Fullsize Pick-ups
3
Feb 12, 2011 8:14 PM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 12:28 AM.