Hi
Can TB gasket leak ?

I cleaned my TB by removing it off the car...reintalled with new gasket(not OEM nissan ... the new one seems little thinner) ...now car at idle is ok (no air leak to hear) but when revving the engine to say 1500+ I hear hissing sound ! ....May be the new (not very good) gasket ?

How can I test it ? i'm sure all my TB work was as good as must be ...

Thanks

 

Way to test it; get some carb/TB cleaner, start the car, and then spray it in the crack where the gasket is. If its leaking the idle will bounce up some.

Yes, they can leak. Are they as prone to leak as say, the manifold gasket or MAF seal? no.

 

how can i check the downside of the gasket by this method ?

 

Just spray it up under there as best you can.

You could also try using a propane torch. Turn it on and dont light it, and if there is a leak, the propane will get sucked in and raise the idle. Its safer than it sounds, but its really a last resort.

 

If you tied the 4 bolts evenly you should not have a problem. I clean my TB and put auto zone gasket on there and never had a problem.

 

x2 on bolt torque.

The FSM calls for torque all 4 bolts to 7 lb-ft, then 15 lb-ft. It is important that the bolts are tightened evenly.

 

I tightned all 4 bolts to hell

 

15 ft-lb is not a lot. Hopefully you did not over tighten them either. Again, the key is to torque them EVENLY.

 

Evenly is the key word! But if you are still having problems you can first get another gasket, or I have seen where some members have used a very light coat of RTV to help seal the deal.

 

Will a TB gasket leak turn on CEL or make a hidden code ? as a bank runs lean or something ? like EGR leaks............

 

A CEL, possibly. It may or may not set a code, it's more a luck of the draw type of thing.