4afe rings gone??? - Toyota Nation Forum : Toyota Car and Truck Forums

big_fella6699 · 06-17-2007, 01:06 AM

hey guys, my ae95 alltrak has just started blowing smoke and using ALOT of oil (almost a sump full every 1.5-2 tanks of fuel.) i was thinking it was the piston rings until i did a compression test. when i checked the compression it showed all cylinders with around 180 psi each. do u think it would b rings? a friend of mine also suggested that rather than the rings eing gone it could be that the bottom of my cylinders are becoming worn which would explain the high compression. does this sound reasonable?
cheers

punter · 06-18-2007, 04:28 AM

I would say it's your oil control rings. They scrape the oil off the bores, which is something the compression rings can't do.

Oil ring failure is pretty common on 4A's (and 7A's).

Flashmn · 06-18-2007, 11:19 AM

Might be valve seals.

Quote:

Oil ring failure is pretty common on 4A's (and 7A's).

Not really on 4A's, its more of an issue of bad rings used on 7A's... Some 2E's/4E's and some 4A's probably got similar ring issues (same ring maker and same issues). Tho atleast over here it was a warranty issue. Anyways, it cant really be rings if all the cylinders are within 10%. Anyways, do a leakdown test, that will tell you where your problems are.
But you're sure you're not leaking the oil? Also check the PCV system if its stuck oil will leak out and burn like nothing you've ever seen.

As for your cylinders becoming worn and the high compression. Actually it goes just the opposite, when your cylinders wear out, the compression gets weaker.

big_fella6699 · 06-19-2007, 05:38 AM

ok thanks, but how do i perform a leakdown test and how do i check the pcv valve?

Flashmn · 06-19-2007, 11:17 AM

leakdown test is done with a leakdown tester. PCV is checked by the instructions in the workshop manual, dont have one here. Pretty much seeing if it flows air through.

tashirosgt · 06-19-2007, 11:23 AM

Would this work?
http://www.xs11.com/tips/misc/misc3.shtml

Flashmn · 06-19-2007, 11:26 AM

I'd just have it tested. trying to do something you have no idea how to do will just cause more problems. If he doesnt know how a leakdown test is done, dont be putting ideas on making your own leak down tester into his head.

91boz · 08-02-2007, 11:28 PM

Quote:

Originally Posted by tashirosgt

Would this work?
http://www.xs11.com/tips/misc/misc3.shtml

Pretty good find! Just what I needed for diagnosing my problem.