Engine Blow By

[PhilGTR]

Hello fellow skyliners!

I have a newbie question. My mechanic says my engine has a bit of excessive blow by. i haveheard this before but can someone explain to me what this means?? If i have this does it mean i need a rebuild soon?

[blind_elk]

Basically the rings are having trouble keeping all the compressed air/fuel mixture in the combustion area. Some of it slips past the rings and starts pressurising the sump.

Probably depends how "excessive" the blowby is. I'm guessing your mechanic has done a leakdown test, so he should know if it is bad enough to start thinking about a rebuild.

[PhilGTR]

oh i see,

Since i just blew my turbos and now i got a couple of new ones, he said that the turbos can handle much more boost but your engine probably wont. So he said it shouldnt be too much of a worry now unless i boost it up. So even if i dont boost it does it mean it will eventually need a rebuild anyway?

[T04GTR]

give it heaps till it gets real bad. it really depends on how much "blowby" its got.

to help it remove and plug the pcv valve. (breather pipe on to of the inlet manifold)

using a 1/4 bsp plug(common as ie, airline fitting thread for rattle gun etc)

also plug the breather going into the rear turbo inlet pipe.

WHERE THE PIPES GO INTO PLUG,DONT BLOCK THE HOSES.

NOW TAKE THESE TWO PIPES AND PUT THEM INTO A CATCH CAN ARANGMENT

venting the can to atmosphere.

this did wonders for my 190000KM old GTR. no mor oil shit getting into the motor :lol:

[R31Nismoid]

give it heaps till it gets real bad?

ugh...

PhilGTR - get a leakdown test done and that will give you a good idea of whats going on.

It might just be you need to use a catch can and go easy on it for extended life. But the test will give you better idea

[PhilGTR]

Yeah i was thinking i might ask him tommorrow when i pick up my car. I cant really afford a rebuild right now and i dont really want to do one anytime soon. Will this mean i will lose power as it is leaking?

[Duncan]

yeah you will be loosing power since the explosion sneaks past the rings instead of pushing the piston down.

What you need is the results of a compression test, then you will know how bad it is. If you want it to last the best thing you can do is turn the boost down and dont push it too hard, but you cant fix it without rebuilding