How much blow by is normal out the oil filler cap?

[Moretorque]

I have some blow by and was wondering how much is normal on a T 1994, Thanks.

 

[JSVD]

my motor does not have much at all.. I don't think anyone can really tell you a point when blowby becomes a negative thing...

I've been told a good test is to turn your cap over and hold it gently on top of the tube... it should stay there... and it should move LESS when someone steps on the petal.

So there should be LESS blowby when your truck is being revved.

 

[Moretorque]

Thanks.

 

[79jasper]

You can test it, but I can't remember the process.
Uses a manometer.

But what's to say x is too much.

Compression/leak down test would tell you all you need to know.

The oil cap test is good for looking at a new truck.
Once looked at a cc 350 psd, it actually blew the cap off at idle.
The car lot had it plugged in. It was summer time...

Sent from my USCC-C6721 using Tapatalk

 

[Moretorque]

When you take the oil cap off it just huffs a little vapor out in like little chugs. I believe it is normal.

 

[79jasper]

Sounds to be normal, comparing to most other idi's.

Sent from my USCC-C6721 using Tapatalk

Edit: the tester is a manometer.

 

[lotzagoodstuff]

If you are concerned about blow by, and you haven't given your truck a dose of AutoRx, you should consider it. I don't think I've ever used a product that genuinely cleaned an engine and brought back power that was lost to carbon/varnish buildup. Follow the directions on the bottle, but to me the only shortcoming of AutoRx is that you can't run down to the corner and buy it at any retail chain.

Good luck