Samurai 20V Posted September 6, 2011 Share Posted September 6, 2011 Hi Guys. I am considering getting the valve stem seals replaced, however I am a bit worried about taking the head off.. On my experience with the 4A-GE 20V engine, it was an issue if the cylinder head was removed and the piston rings not replaced, the motor would always end up smoking and have to be opened up again to replace piston rings.. Has anybody experienced the same with the 2JZ? I gather the issue with the 4A-GE was weak rings specified from the factory... Basically has anybody removed the head without touching the bottom head, and had issues with loss in compression after that? Quote Link to comment Share on other sites More sharing options...
Scott Posted September 6, 2011 Share Posted September 6, 2011 I dont get that, what difference does removing the head make to the rings? They are completely seperate, or does the 4AGE run proud deck or something? I can't see any way that removing the head will effect anything that isnt head related. I just removed mine and I'm in the process of putting it back in. I will say that if I was doing the stem seals I wouldn't remove the head. Far easier and quicker to do it in situe. Quote Link to comment Share on other sites More sharing options...
heckler Posted September 6, 2011 Share Posted September 6, 2011 I dont get that, what difference does removing the head make to the rings? They are completely seperate, or does the 4AGE run proud deck or something? I can't see any way that removing the head will effect anything that isnt head related. I just removed mine and I'm in the process of putting it back in. I will say that if I was doing the stem seals I wouldn't remove the head. Far easier and quicker to do it in situe. Toyota reccommend you use compressed air to keep the valves shut! - or use the rope method... Quote Link to comment Share on other sites More sharing options...
Scott Posted September 6, 2011 Share Posted September 6, 2011 Toyota reccommend you use compressed air to keep the valves shut! - or use the rope method... Yeah, it would be the rope trick for me. I dont have a compressor lol. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted September 6, 2011 Author Share Posted September 6, 2011 (edited) I dont get that, what difference does removing the head make to the rings? They are completely seperate, or does the 4AGE run proud deck or something? I can't see any way that removing the head will effect anything that isnt head related. I just removed mine and I'm in the process of putting it back in. I will say that if I was doing the stem seals I wouldn't remove the head. Far easier and quicker to do it in situe. I think it is to do with relieving the seal of the cylinder, not sure, hence my question.. 4AGE is the usual setup similar to the 2JZ.. Are you planning on doing a compression test after re installing the head? Edited September 6, 2011 by Samurai 20V (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 6, 2011 Share Posted September 6, 2011 I am extremely familiar with 4A-GE engines and there's absolutely nothing special about them at all that would make head removal and replacement 100 times over have any effect whatsoever on piston ring sealing unless you get a load of debris down the bores, as with any engine. Quote Link to comment Share on other sites More sharing options...
Scott Posted September 6, 2011 Share Posted September 6, 2011 I think it is to do with relieving the seal of the cylinder, not sure, hence my question.. 4AGE is the usual setup similar to the 2JZ.. Are you planning on doing a compression test after re installing the head? Yeah but only because I've changed the actual head, valves, springs & retainers etc. Not because I'm worried about the piston rings..... as per what Chris said. I am extremely familiar with 4A-GE engines and there's absolutely nothing special about them at all that would make head removal and replacement 100 times over have any effect whatsoever on piston ring sealing unless you get a load of debris down the bores, as with any engine. Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted September 6, 2011 Author Share Posted September 6, 2011 I am extremely familiar with 4A-GE engines and there's absolutely nothing special about them at all that would make head removal and replacement 100 times over have any effect whatsoever on piston ring sealing unless you get a load of debris down the bores, as with any engine. The 4A-GE 16V engines were fine, it was the 20V engines that used to have these issues... I think it was bad machining from the factory, coupled with poor quality rings.. Anyway, if many have opened up the 2JZ and not had these issues then it is limited to the 4A-GE engine... BTW Chris, how is the availability of spares for the 4AGE in UK? Quote Link to comment Share on other sites More sharing options...
Monster supra Posted September 8, 2011 Share Posted September 8, 2011 Changed head gasket on mine last week & everything is fine No loss of power No smoking . Quote Link to comment Share on other sites More sharing options...
Samurai 20V Posted September 9, 2011 Author Share Posted September 9, 2011 Changed head gasket on mine last week & everything is fine No loss of power No smoking . Cool! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.