I took throttle body off and on top were the vac lines go there was some fresh oil, is that from bad pvc value? The reason I was taking apart throttle ,was I can here a mild whistle noise when I press throttle. I have a stall when give gas. Ive sprayed carb cleaner trying to find leak no change.
fresh oil on top throttle body
- Thread starter ricturbo
- Start date
it was on top of throttle body on the side were the vac line comes from pcv.
how can I tell?
MeanBuicks
Scaring the neighbors!
- Joined
- May 24, 2001
Put everything back together and start the engine. Spray some starting fluid around the suspect areas and see of the idle speed changes. If so, you know it's ingesting the fluid through a vacuum leak.
I tryed carb cleaner do you think that would have changed idle?
ok thx
H
Heisenberg
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H
Heisenberg
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You can tell if you are using the stock, plastic vacuum block - it will be deformed in the middle
Concave - near the two bolt heads
Swap out to an aluminum block.
cheap fix and solid upgrade
I'm not clear on whether the oil is leaking from the vacuum block gasket - or if it was noticeable when you removed the vacuum block.
If the latter - join the club.
I've not see a whole lot of weeping oil out from under the gasket but I suppose it is possible.
A smudge here n there, but not running
But a gasket fixes that. 5 bucks
Change that PCV - it is probably shot.
It's really not intended to shuttle tons of oil through the intake system - but crankcase vapors; i.e. blow by; ergo for environmental concerns
If it is sucking a ton of oil, you may have some other things going on.
Obviously, an evac catch can system is preferred for use on the valve covers to evacuate oil suspended in the crankcase vapors.
Install a 3/8" check valve inline with the PCV.
No matter what you hear - they all leak under boost; and allow crankcase pressures to increase.
H
Heisenberg
Guest
A boost tester can help you spot a multitude of previously unknown minor leaks.
Vacuum lines, split connectors, TB seals gone bad, etc etc.
Well worth either making your own for 10 bucks or buying one for 25
A very useful tool to have.
It helps you check your entire system - if you don't have a smoke machine.
My thinking is it is superior in some ways - as you can actually set the PSI to what you will see in your real world boost condition and not rely on smoke to find its way under minimal pressure.
Where can you get the boost tester?
H
Heisenberg
Guest
H
Heisenberg
Guest
H
Heisenberg
Guest
I use an inline filter / regulator to adjust air compressor PSI so I don't have to fiddle with the main one.
I keep this one set for 25 psi to test all kinds of things; PCV's; intake, TB's and intercoolers I purchase etc.
And if you will notice - I made an adapter for mine which allows me to plug the air hose directly into the boost tester - allowing a continuous flow of air - vs just pumping it up like a tire and then having it leak down.
I keep this one set for 25 psi to test all kinds of things; PCV's; intake, TB's and intercoolers I purchase etc.
And if you will notice - I made an adapter for mine which allows me to plug the air hose directly into the boost tester - allowing a continuous flow of air - vs just pumping it up like a tire and then having it leak down.
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Heisenberg
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Kiddie blow bubbles works ok - $1 at Dollar Tree for a big ole bottle
Commercial type liquid is called "Snoop" or other brands. Used for natural gas leak detection But pricey
Best if you can find a squeeze bottle with a small tube - squeeze the liquid on vs spraying - which creates bubbles in the spraying process
I've used Dawn dish wash soap and water - but the results while ok, are not ideal.
But if you leave it sit long enough - it will eventually start blowing bubbles.
And I found that the Dawn dish soap has a caustic element to it, and scars my aluminum pieces if left to sit on too long and dry.
I've found some crazy leaks.
Vacuum hardlines split right at the brazing point, TB seals, IAC seals, split rubber vacuum connectors, on and on.
And oh - that big ole 3/8" PCV blowing a ton of air into the crankcase.
Commercial type liquid is called "Snoop" or other brands. Used for natural gas leak detection But pricey
Best if you can find a squeeze bottle with a small tube - squeeze the liquid on vs spraying - which creates bubbles in the spraying process
I've used Dawn dish wash soap and water - but the results while ok, are not ideal.
But if you leave it sit long enough - it will eventually start blowing bubbles.
And I found that the Dawn dish soap has a caustic element to it, and scars my aluminum pieces if left to sit on too long and dry.
I've found some crazy leaks.
Vacuum hardlines split right at the brazing point, TB seals, IAC seals, split rubber vacuum connectors, on and on.
And oh - that big ole 3/8" PCV blowing a ton of air into the crankcase.
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H
Heisenberg
Guest
If you do this test dont forget to take rocker shafts off so all the valves are closed. lol
H
Heisenberg
Guest
Actually - no - you really don't have to at all.
You'll be surprised at how much the TB butterfly seals things.
My goal for this test is to check the intake tract from the Turbo inlet bell, all the way to the TB butterfly.
Past the TB - The plenum, intake etc is another story.
But this side of things still tests the usual culprits, i.e leaking rubber lines, check valves, hardlines, gaskets, intercooler, etc.
And sort of real easy, quick, basic test to validate the hundred things strewn across the top the engine that are pretty prone to leaking
You can have this thing on and off, test all the points, in an hour or so.
And you either leak boost (pressurized air) - sometimes in the wrong places - or are sucking in unmetered air.
