Pressure testing the intake system .......Continued

Phil Rose pjrose at
Sat Jul 31 09:13:59 EDT 2004

At 5:23 PM -0700 7/30/04, 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 believe you are _not_ correct about that. The procedure I followed 
was to remove the  hose ( from the forward outlet of the pressure 
valve) and insert a plug (into the hose) during the pressure testing. 
A wine-bottle cork fits nicely. This eliminates the leakage that can 
occur via the crankcase breather system (dipstick, etc). Perhaps it's 
possible to simply clamp off the hose (vise-grip?), instead of 
inserting a plug.

>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,

dipstick plug is unecessary  if the crankcase breather is clamped 
shut or disconnected as  described (above). However, in any event 
it's good to have a tightly fitting o-ring seal for the dipstick. 
Even with a good o-ring, the pressure testing can "blow" the dipstick 
unless the breather is disconnected.

>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 would think that's correct (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).

How old are the plugs, and are they the oem specified ones??? They do 
tend to loosen considerably over time, so I'd advise removing, 
cleaning and re-tightening each plug.

>  Found some seepage at the rear of the valve cover also( while I was 
>looking around).

Very common. Such seepage (and elsewhere) became evident within 6 
months after I installed a brand-new gasket. Oil seepage into the 
sparkplug ports is potentially more serious. I didn't have that 

>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).

Someone on the list was encountering the very same smog test problem, 
not long ago.


Phil Rose
Rochester, NY USA
mailto:pjrose at

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