Failed Boost leak test = bent valves?

[TurboTJ]

I recently replaced my timing belt tensioner. While doing so, I had the timing belt completely off. I reinstalled it, achieved the proper extension on the tensioner and put it all back together. When I started it up, it ran kind of rough. The wideband was reading 10:1 A/F. It drove fine and started making me think that the wideband sensor was bad. I performed a boost leak test and found that I could only hold 1 PSI. I could not find or hear any boost leaks. Only a somewhat faint whistle after I stopped pumping air in.

Could I have possibly bent the valves and now the air is going through the engine and escaping through the exhaust?

Here are the facts:

-Running rich all the time. (But I did see the gauge hit 14.7 once at idle)
-Car has not been started in 6 weeks until now
-power seems decent (though I am not flooring it)
-I turned the crank over after installing the timing belt 3x with no problems
-boost still comes on easy when I open up the throttle.

thanks for the help!

 

[HIGHPSI4]

If the car is still running then your valves are still good. Not all the valves are closed when the engine is shut off.

 

[silver bullit]

Do a compression test.

 

[turbobird14]

are you certain that you dont have any leaks in the intercooler piping... i had a leak in the intercooler itself and couldnt hear or see anything when doing a boost leak test. try using a spray bottle with soap and water. it works really well

 

[fubar_mdw]

I would do the compression test on it.
i had almost the problem awhile ago but didnt have much of any power and
i had bent the valves.

 

[TurboTJ]

I would do the compression test on it.
i had almost the problem awhile ago but didnt have much of any power and
i had bent the valves.

Did you have the same results from a boost leak test?

 

[Splitpi]

Did you have the same results from a boost leak test?

Do the test. If you have bent valves and your boost leak test is registering 1 psi max, then the compression test will have very low numbers aswell. Do the compression test. It will give you your answer to this question quick enough. No one else can solve this question for you but you.

Though most likely you have a boost leak somewhere in your IC path that you are just not finding or your pressure source is flowing less than the boost leak so you cannot pressurize it enough, fast enough to find the leak.

Assuming the compression results come back fine (which they generally will), then you need to try and use some soap/windex and find your boost leaks on the IC tubing/IC itself.

Try all coupling joints, try TB gaskets, get creative.

 

[1gDSM4g63]

I have similar problem with my car I left sitting for over six months, the wideband readings are erratic when idle even with insane SAFC adjustment on 950cc, no boost, compression check outs, cannot find any boost leak, and car dies down when in 2nd or 3rd gear at random times.

are you certain that you dont have any leaks in the intercooler piping... i had a leak in the intercooler itself and couldnt hear or see anything when doing a boost leak test. try using a spray bottle with soap and water. it works really well

I figure it is a boost leak even though I'm certain it wouldn't cause this much problem but as using the spray bottle do you spray water in the intercooler?

I would do the compression test on it.
i had almost the problem awhile ago but didnt have much of any power and
i had bent the valves.

If the compression test checkes out doesn't that eliminate having anything to do with the valves?

 

[bane3d]

I figure it is a boost leak even though I'm certain it wouldn't cause this much problem but as using the spray bottle do you spray water in the intercooler?

Don't spray into the intercooler, spray the joints of your system. You are looking for compressed air leaking out of the joints so you should see small bubbles on the places that are leaking or possibly a small to large hiss where-ever you have a leak.

If the compression test checkes out doesn't that eliminate having anything to do with the valves?

Correct, if you are good across the board, then you don't have bent valves or a bad head gasket.

d

 

[TurboTJ]

Because I can't hear anything, I think that if it is a boost leak, it must be big.

Where do I get the tool to run a compression check? is it just a standard tool that screws into the spark plugs hole?

thanks for all the help

 

[snowborder714]

Because I can't hear anything, I think that if it is a boost leak, it must be big.

Where do I get the tool to run a compression check? is it just a standard tool that screws into the spark plugs hole?

thanks for all the help

Here's a compression kit:

Harbor Freight Tools - Quality Tools at the Lowest Prices

And you might actually be able to rent one for free from Auto Zone/Advance Auto Parts.

 

[romeen]

Do the compression test first as everyone else stated. When you repeat the boost leak test turn the motor to 30* ATDC to avoid valve overlap and use the soapy water as mentioned. Let us know the results.

 

[Defiant]

Wait, wait, wait, waitagoddamned minute.

I recently replaced my timing belt tensioner. While doing so, I had the timing belt completely off. I reinstalled it, achieved the proper extension on the tensioner and put it all back together. When I started it up, it ran kind of rough.

Step ONE: is your timing correct?

 

[Street_Killer]

Wait, wait, wait, waitagoddamned minute.
Step ONE: is your timing correct?

Thats funny, I was wondering the whole the same thing the whole time I read this, because you said nothing about the timing besides tensioning it.

 

[1gDSM4g63]

The compression checks out and the boost leak and the leak down is all fine but the wideband readings are still erratic even with insane SAFC adjustment during idle, no boost, and the car dies down when throttling it at random time with in 2-3-4 gear.

Any other suggestion why this is happening?

 

[Splitpi]

The compression checks out and the boost leak and the leak down is all fine but the wideband readings are still erratic even with insane SAFC adjustment during idle, no boost, and the car dies down when throttling it at random time with in 2-3-4 gear.

Any other suggestion why this is happening?

Is your timing correct? Is your fuel line clogged, fuel filter? Is your pump weakening? Injectors clogged?

 

[KRRZ350]

A vacuum reading @ idle will be helpful in determining if your cam timing is off.