Have you replaced the "O" ring on the throttle body ?

( where are you located ? )

 

yeah, 2 times, the last was made with rtv sealant...

Im not from US, Europe.

 

do you know if oil dip stick tube lower seal can cause crankcase vacuum leak? i think it can be, because when i take off and block all breather hoses fuel trims become normal.

 

I had a problem like this with the TB mounting spacer. Its capable of separating from the flange though youll miss it unless you take it all apart as I did. Believe I had a POSTING about it WY.

 

https://www.crossfireforum.org/forum...imp-power.html

post #17 fyi. woody

 

mine is NA, dont have any spacers there

 

Take a length of hose 3 ' long and use it to hear the location of the leak. Keeps your hands out of harms way and you ear will locate the sound source easily, old school trick. Woody

 

actually i have localized the noise, it completely gone when i disconnect and block pcv hoses from them intake Y connector, but the question remains - why these hoses cause a kind of vacuum leak for the system? tried to smoke valve covers with intake, no obvious leak there, please advise if you know how exactly ventilation works?

 

Each of the valve cover vent covers where the small hoses connect have a tiny hole into the valve cover.
It's just that simple, the manifold vacuum draws the engine fumes through these two tiny holes
and the fumes/oil vapors are burned in the combustion chambers.
The NeedsWings oil catch can replaces these 2 hoses with longer ones that go to the intake of the catch can.
There is then another hose from the catch can to the "Y" connector, the other port of the "Y" connector is capped off.

Yes, I can hear the hissing at the connector point on the covers even without using Woody's hose method, it is considered "normal"

The LARGE hose on the driver's side vent cover is the "equalization" hose, it connects BEFORE the throttle body and serves to equalize the internal
pressures with the outside atmosphere. DO NOT CAP THIS HOSE OFF !!!
Ask me how I know : I thought it redundant and capped both ends once, you never heard such noises from an engine like I had.
I swore it was my water pump going bad, once I put the hose back on, all was well again.

 

i have friends e320 and his engine do not have such hissing sound

 

from a google search :

 

i know this without google) i meant more detailed explanation with internal engine passages

 

I will politely bow out at this point, someone with more expertise ( brains ) please take over.

 

So recently removed my intake and repositioned my catch can and immediately after the Check engine light came on. I currently have lean codes bank 1 and 2 that won't go away.


Step 1. I had just rebuilt my needswings intake, and found several loose bolts. All have been tightened. Still lean.




Step 2. I found 4 loose bolts at throttle body, tightened. Still lean.


Step 3. Moved my catch can ( not needswings) behind the heat shield on the pass side to keep the intake cooler. Under the hood is a bit cooler but I am still lean. My next step is the check all the fittings on the catch can to see if there is a vacuum leak before the TB.


Back to step 2. I found the TB bolts super loose. Did I read that the TB gasket can fall out of place?


I think I will remove the TB all together and check the gasket. Ideas and thoughts are welcome!

 

I have removed 4 original throttle bodies to date for the 74mm update, and on all 4 the OEM O ring was toast.
Get a new O ring before you take the TB off.

 

somewhere on our forum is a picture of the engine with a vacuum tube running down the front of it. The thread says, everyone forgets this vac tube and it gets old and wears out. I can't find the picture to save my life. I found the tube and sure enough, it turned to dust in my hand. I can't for the life of me figure out where that little tube inserts in the belly of the engine.


Please help. Daily driver.


Found it. blah just a few post ahead of this one.... not sure how I am going to get a hose on that??? I deffinately cannot reach it. What do I do now? /There has got to be a trick to getting to that nipple.

 

How on earth do I reach that nipple on the bottom of the throttle body to connect a new hose?

I'm dumbfounded.

 

NO NIPPLE? WTF. WHAT GERMAN M#%^^#@#$@!. DESIGNED THIS.

This hose inserts from inside the manifold? YGTBFKM

 

The one in charge of selling replacement parts!

Haven't dealt with it..
hopefully won't have to ..
but did read a couple threads on it..

 

Well at 155K, this is the first real problem I have had. If you would be so kind as to shoot up a link regarding that hose and it's replacement. I am afraid I am going to have to find a manifold with the hose intact. Or at least remove the manifold, and engineer something more permanent. Hopefully the threads include an easier fix than what I have in mind.

If i have to take off the manifold, I am going to have to look for a bigger one that fits now....

Anyone attempting to replace this hose should carefully inspect the entire hose. I believe my insertion of the hose was in much better shape than the part the turned to dust when I touched it. I could have cut the hose mid way and used a two sided brass nipple to connect a new piece of hose. Problem solved. I assumed that there would be a nipple at the bottom of the manifold as there are on the top for 2 more suspect lines. NOPE! My hoses connected to these nipples looked ok but definitely were taking a beating from all the heat in the front of the manifold.

Hopefully this post will help save someone a few hours.