S13 SR20DET Strong pulse of Air Going Threw My Valve cover & Oil Cap When in Idle?

[240sx_LokiS14]

Hello guys i hope you guys can give me some input on my situation. I have a S13 RedTop SR20det ive notice i got a strong pulse of air coming out of my head threw the oil cap when i open it. I don't know if boost is getting to the head or if my vacuum lines are hooked up wrong or if i have bad piston rings? Ppl are telling me it can be either one of those three so Ive been researching this for about 2 weeks trying to figure out why its doing that all the power is still there it's not smoking or anything but my spark plugs tend to get charcoal black really fast. I think i might be running to rich?

What tests can i run to figure out if its anyone of those problems?

:bite::bash:

[TheWolf]

it's called blow by.

you can test it by performing a cylinder leak down test.

Tester is available cheap at harbor freight.

[240sx_LokiS14]

Did a Compression test my cylinder,1,110psi cylinder,2,100psi cylinder,3,110psi cylinder,4,110psi

Looks Like Its Time For A Rebuild Sigh :-/

[TheWolf]

Did a Compression test my cylinder,1,110psi cylinder,2,100psi cylinder,3,110psi cylinder,4,110psi

Looks Like Its Time For A Rebuild Sigh :-/


Notice I said leak down.. not compression.

Compression tester gauges can be off for a variety of reasons and usually are only for checking for variances between the holes and not the quality of the hole. A leakdown is for that. Do a leak down. listen for where air is escaping. Report.

[240sx_LokiS14]

Notice I said leak down.. not compression.

Compression tester gauges can be off for a variety of reasons and usually are only for checking for variances between the holes and not the quality of the hole. A leakdown is for that. Do a leak down. listen for where air is escaping. Report.

allright ill do a leak down test soon. but if its leaking what does that mean?

[Memberofthe600hpkaclub]

Time for a hone job and new rings if soooooooo

[fliprayzin240sx]

allright ill do a leak down test soon. but if its leaking what does that mean?

Yah, leak downs are more accurate but with the numbers you came up, rings are done. Minimum compression for each cylinder, per the FSM is about 125 psi.

[240sx_LokiS14]

Should i still attempt to do the leak down test then?

[Kingtal0n]

wow.

I have a S13 RedTop SR20det ive notice i got a strong pulse of air coming out of my head threw the oil cap when i open it.

This ^^ is completely normal for all SR20DET engines. This is not BLOW BY.

your compression does seem a bit low, did you remember to hold the throttle open when you did the test?
Since all cylinders report the same numbers, I would not worry about it. Could be carbon buildup on the valves plus the fact these redtop engines tend to sit for years before someone installs them here in the USA. I had one like that, it was telling me (90, 110, 115, 115) took it apart expecting to find busted rings or something... turned out to be thick carbon chunks on the valves were holding them open slightly.
I've seen RB engines like that also.

There are many solvents you can buy that will remove carbon. Might want to try some of those before taking anything apart.

[240sx_LokiS14]

wow.


This ^^ is completely normal for all SR20DET engines. This is not BLOW BY.

your compression does seem a bit low, did you remember to hold the throttle open when you did the test?
Since all cylinders report the same numbers, I would not worry about it. Could be carbon buildup on the valves plus the fact these redtop engines tend to sit for years before someone installs them here in the USA. I had one like that, it was telling me (90, 110, 115, 115) took it apart expecting to find busted rings or something... turned out to be thick carbon chunks on the valves were holding them open slightly.
I've seen RB engines like that also.

There are many solvents you can buy that will remove carbon. Might want to try some of those before taking anything apart.

Ill Run A Leak Down Test first See How That Goes If it shows its fine then imma seafoam the car.
After u did the solvents how did your car react after? and how was ur compression numbers like?

[240sx_LokiS14]

So before all this happen to my car i would run my car threw the canyon a couple of times and my car would start bogging. The rpm takes forever to pick up i can feel it boosting but its hesitating to pick up. IDK if this will help with anything or give a better look at my issue that is going on ATM.

Input plz.

I Ran Seafoam threw my car today it runs alot smoother n stronger. now i gotta do a leak down n compression test.

[Kingtal0n]

Cleanliness is a very important overlooked aspect of internal combustion engines. Even something simple like an oil change can have a dramatic long term effect on engine longevity if done improperly. And you see people running without air filters... do not do that! Even normal "clean outside air" can have hundreds of thousands of tiny particulate... a pinch of soil can hold over 2 million single cell organisms! the stuff is everywhere!


Organisms are made of carbon, and carbon burns, or at least it tries. It forms deposits, fact of life. Keeping the inside of an engine clean is paramount, and it takes more than just an air filter to do that.


if your engine reacts to "cleaning type solvents" then I would recommend a thorough cleaning. that is, remove everything you can, and literally degrease/scrub it. Anything that you are competent enough to remove and replace, including all plumbing, the inlet, the intake manifold, every crevice before the engine that air flows through should be clean as possible.

Keep using solvents that remove carbon but dont go crazy. If you have a large chunk fall off it can do damage. you want to generally gradually remove the carbon with solvents. The best way obviously is to remove the head and do it mechanically by hand where you can see what you are working with.

The engine's compression will return to normal once all of the surfaces involved with cylinder sealing are properly fitting together once more (such as valves that properly seat after the carbon buildup was removed) Your leakdown test will shed some light on that aspect, and you can hear where the air is going (you might even put your mouth on the dipstick tube while doing the test to sense air entering the crank case) listen to the exhaust plumbing for leaky exhaust valves as well. Experiment with the lines on the valvecover (they should be cleaned as well) remove them and inspect / change the pcv valve if possible for routine maintenance, any seal/gasket/valve should be replaced anyways if it is very old, these engines are already 20 years old so it is a good idea.


I had an RB25 giving low compression on several cylinders. Like i said I thought the rings were gone, first I took the head off. I noted the enormous carbon buildup, and used some fancy Toyota solvent "brakecleen type solvent" to soften it up (dissolved it) and took a few hours of wiping to get it spotless again. Put the head back on and the engine was like brand new.

[240sx_LokiS14]

Cleanliness is a very important overlooked aspect of internal combustion engines. Even something simple like an oil change can have a dramatic long term effect on engine longevity if done improperly. And you see people running without air filters... do not do that! Even normal "clean outside air" can have hundreds of thousands of tiny particulate... a pinch of soil can hold over 2 million single cell organisms! the stuff is everywhere!


Organisms are made of carbon, and carbon burns, or at least it tries. It forms deposits, fact of life. Keeping the inside of an engine clean is paramount, and it takes more than just an air filter to do that.


if your engine reacts to "cleaning type solvents" then I would recommend a thorough cleaning. that is, remove everything you can, and literally degrease/scrub it. Anything that you are competent enough to remove and replace, including all plumbing, the inlet, the intake manifold, every crevice before the engine that air flows through should be clean as possible.

Keep using solvents that remove carbon but dont go crazy. If you have a large chunk fall off it can do damage. you want to generally gradually remove the carbon with solvents. The best way obviously is to remove the head and do it mechanically by hand where you can see what you are working with.

The engine's compression will return to normal once all of the surfaces involved with cylinder sealing are properly fitting together once more (such as valves that properly seat after the carbon buildup was removed) Your leakdown test will shed some light on that aspect, and you can hear where the air is going (you might even put your mouth on the dipstick tube while doing the test to sense air entering the crank case) listen to the exhaust plumbing for leaky exhaust valves as well. Experiment with the lines on the valvecover (they should be cleaned as well) remove them and inspect / change the pcv valve if possible for routine maintenance, any seal/gasket/valve should be replaced anyways if it is very old, these engines are already 20 years old so it is a good idea.


I had an RB25 giving low compression on several cylinders. Like i said I thought the rings were gone, first I took the head off. I noted the enormous carbon buildup, and used some fancy Toyota solvent "brakecleen type solvent" to soften it up (dissolved it) and took a few hours of wiping to get it spotless again. Put the head back on and the engine was like brand new.

In The Process ATM. thx for the input. :3

[KoukiMonsta]

Cleanliness is a very important overlooked aspect of internal combustion engines. Even something simple like an oil change can have a dramatic long term effect on engine longevity if done improperly. And you see people running without air filters... do not do that! Even normal "clean outside air" can have hundreds of thousands of tiny particulate... a pinch of soil can hold over 2 million single cell organisms! the stuff is everywhere!


Organisms are made of carbon, and carbon burns, or at least it tries. It forms deposits, fact of life. Keeping the inside of an engine clean is paramount, and it takes more than just an air filter to do that.


if your engine reacts to "cleaning type solvents" then I would recommend a thorough cleaning. that is, remove everything you can, and literally degrease/scrub it. Anything that you are competent enough to remove and replace, including all plumbing, the inlet, the intake manifold, every crevice before the engine that air flows through should be clean as possible.

Keep using solvents that remove carbon but dont go crazy. If you have a large chunk fall off it can do damage. you want to generally gradually remove the carbon with solvents. The best way obviously is to remove the head and do it mechanically by hand where you can see what you are working with.

The engine's compression will return to normal once all of the surfaces involved with cylinder sealing are properly fitting together once more (such as valves that properly seat after the carbon buildup was removed) Your leakdown test will shed some light on that aspect, and you can hear where the air is going (you might even put your mouth on the dipstick tube while doing the test to sense air entering the crank case) listen to the exhaust plumbing for leaky exhaust valves as well. Experiment with the lines on the valvecover (they should be cleaned as well) remove them and inspect / change the pcv valve if possible for routine maintenance, any seal/gasket/valve should be replaced anyways if it is very old, these engines are already 20 years old so it is a good idea.


I had an RB25 giving low compression on several cylinders. Like i said I thought the rings were gone, first I took the head off. I noted the enormous carbon buildup, and used some fancy Toyota solvent "brakecleen type solvent" to soften it up (dissolved it) and took a few hours of wiping to get it spotless again. Put the head back on and the engine was like brand new.

This is quite an interesting post

[Kingtal0n]

Did I say 2 Million? I meant 2 Billion. My bad.
A million occur in 1ml of Sea water.

http://zilvia.net/f/attachment.php?attachmentid=43421&d=1347985793

[Kingtal0n]

Fungus is a major contributor of air particulate. They are trying to grow on everything, and eat it. A burn victim, for instance, is at risk of fungal infection simply because the fungus is practically everywhere. We inhale them every day, and people with weak immune systems, such as AIDS patients, are under constant risk of infection.



http://i23.photobucket.com/albums/b378/draglarry/fungus.jpg