Pressure testing the intake system .......Chapter 3

Chuck Pierce cpcycle at
Sat Jul 31 18:21:47 EDT 2004

Chapter 3

A friend has a smog test/repair shop, so today I took the beast down to 
him to see if we find out the problem of not passing the test.
( I could not use him for the testing portion as I had to take the car 
to a test only shop.....a california thing)
He pulled out his O2 sensor tester and the O2 sensor was good ( at least 
something is going right!)
The car is still running pretty rich as the Hydrocarbons are pretty high
Then he compared the exhaust gases at the sampling port right after the 
turbo and the tail pipe there was very little change. So this means that 
the cats are toast.
The car uses some oil probably about 1 qt per 800mi..
So I guess it is time to do a leakage test to see where the problem is.
 The car doesn't seem to smoke on deceleration ( valve guides) and the 
compression was good when I got the car 2 years ago.
Have the turbos been known to leak oil to cause something like this?
Any more wisdom accepted!!!

Thanks for all the input gang.

Chuck Pierce
91 200tq 20v Avant

Chuck Pierce wrote:

> Continued from earlier:
> I fixed the hose and found that the crankcase pressure valve also 
> leaks with the system pressurized, if I am correct that is not 
> supposed to happen.
> I went out and got a barbed tubing elbow to replace the crankcase 
> pressure valve so I could continue to look for leaks.
> Found some air coming out from the dipstick, plugged that, now it 
> seems that I have some leakage around the injectors where they go into 
> the intake manifold this is probably not a good thing.
> I did not use more than 20psi for this testing. I did not seem to hear 
> any leaks coming from the front end of the car( intercooler & 
> connections).
> Pulled the spark plug wires out and found the #5 plug connector had 
> some oil on the end. So this probably means the valve cover gasket is 
> leaking ( at least the portion that seals the #5 spark plug hole). 
> Found some seepage at the rear of the valve cover also( while I was 
> looking around).
> Still do not think I have found why the car failed the smog test with 
> really high hydrocarbons ( 193 ppm with a 120 ppm Mx  at the low speed 
> test).
> So if any one has some BTDT experience to relay please do. I am new to 
> the turbo charging and EFI so the learning curve is a bit steep.
> Thanks
> Chuck
> Chuck Pierce wrote:
>> Since the car did not pass smog I figured I would pressure test the 
>> intake system before i ripped into the car.
>> I found the short hose going from the crankcase pressure valve( this 
>> is the valve under the bend in the intake manifold) has a huge hole 
>> in it. I am headed to the local FLAP to get a piece of hose
>> Will the a pressure leak like this cause the car to run rich?
>> For all I know I will find more leaks after I get this one fixed.
>> Opinions please
>> Chuck Pierce
>> 91 200tq 20v Avant
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