Valve seals or valve guides?

[ShadowFromHell]

My neon is has started doing the typical decel valve guide/seal smoke. I picked up a 40k head for it, but then got wondering if it is the seals or the guides. I can do the seals in the car and save time and money (bought the head CHEAP). Ive asked around and no one can tell me how to tell if its the guides or the seals. Is there a way to tell, or is it a gamble? Id hate to change the seals and then still have to change the head. But at the same time, Id much rather just change the seals then crack the motor apart to swap the head.

Thanks!

[turbovanman²]

Check the plugs, if it looks like one side of the plug is covered in fuzz or dark, the other clean, valve seals, if the whole plug, rings. If you can look into the cylinders, see if the piston is clean at 12 and 6 oclock, if clean, rings, if the whole piston is dark, then seals/guides.

[ShadowFromHell]

But how do you tell if it is the guides and seals, or JUST the seals?

[turbovanman²]

But how do you tell if it is the guides and seals, or JUST the seals?

You can't without removing the seals, then you have to remove the air or the device holding the valve up, then move the valve slightly down and wiggle, if it has excessive clearance, its guides.

[ShadowFromHell]

So the only real way to check them, is to have it apart. Thats what I was afraid of. Ohh, well I have a fresh head for it.

[black86glhs]

Your motor will like getting fresh head.

[turbovanman²]

Your motor will like getting fresh head.

[zin]

Your motor will like getting fresh head.

Careful... nice, clean, tight head might "blow" your rings...

Sorry, had to play on that comment, but seriously, if the bottom end is tired, like the head, the rings might go a bit south once the top-end is holding everything in...

I'm not saying don't do it, but be prepared if the rings start to go away.

Mike

[black86glhs]

Oh stop...your no choir boy, either.......lol.

[turbovanman²]

Oh stop...your no choir boy, either.......lol.

I won't argue with you there,

[ShadowFromHell]

Careful... nice, clean, tight head might "blow" your rings...

Sorry, had to play on that comment, but seriously, if the bottom end is tired, like the head, the rings might go a bit south once the top-end is holding everything in...

I'm not saying don't do it, but be prepared if the rings start to go away.

Mike

Thats why I was asking if there was a way to tell if it was the seals or the guides. The original plan was just to swap the head, but the more I thought about it I might as well do a full rebuild while it is apart. I was thinking if I could just change the seals, it would keep things from spiraling out of control... It doesnt help either that the shell isnt really in great shape, and a new motor will cost about what the car is worth, even with me doing all the labor.

[Shadowv4l]

well, pop the valve cover off and take a peak at the seal through the springs. If they are leaking that bad then you may be able to see if they are dry and cracking. Then its just a matter of popping off the cam and pressurizing the cylinder through the spark plug hole (with a compression tester hose connected to shop air) and renting a on-car valve spring comressor tool from autozone. I know this because I did this a week ago on my brothers omni to replace suspect valve guide seals. Also no fancy tool required for popping them off and on, just use a screwdriver and a socket.

[zin]

That's a good idea, if they are original, there is a good chance that they are cracked or gone altogether, and even if the guides are worn, the new, soft/conforming seals would likely cure the problem until a new engine is built, saving the fresh head can be saved for that project.

Mike

[ShadowFromHell]

As far as I know they are original. This car has been around the block a few times... It was originally a 2.0 DOHC sport, then that motor got hydro locked and a used PT 2.4 was swapped in. Then it was sold, and that guy pulled all the 2.4 stuff to put in his 95 ACR, and the motor from the ACR was put into my coupe. Thats when I bought it. I think the motor has around 130-140k on it. I do know when the motor was in the ACR it had the water pump, t-belt, and HG changed around 100k. But I doubt the valve seals were changed. Any idea what kind of tool I need to compress the valve springs in the car, is it a Chrysler specific tool or will something universal work?

[Shadowv4l]

just a normal on-car tool will work, it pretty much works the same as a spring compressor for a strut. Rent one at autozone for 25 bucks, it worked so well for me i was thinking about just keeping the tool and not returning it.

[ShadowFromHell]

Well I did some research on the kind of tool that is needed on a DOHC neon head to pull the valvesprings and found out to pull them I need to take the cams out as the valvesprings are under the cams. One of the main reasons I didnt want to pull the head is I didnt want to mess with timing the motor, as its alot more complicated then our 8v motors. But if I have to pull the cams I am really not that far away from just swapping the head. To me, swapping the head looks like it will be the easy part, the PITA part will be the timing. So I might as well just swap the head and be done with it. Seals are cheap however, so the new head will be getting them before it goes in.

[Shadowv4l]

I take it you havent worked on that many types of cars. The timing on anything chrysler isnt that scary. If you wanted to you could try popping off the cam gear without having the belt slip (clamp the belt to the gears), that way when you are done with the cams you can try slipping the gears back on without messing with timing to much, of course this may require loosening the tensioner a bit. I would give it a try before pulling the head, i try not to replace the HG unless i really have to. And air-tools are your friend when it comes to cam gear bolts.

[ShadowFromHell]

Im not scared of doing it, what I meant by harder then timing our 2.2's is you HAVE to tear all the covers off, and pull off the crank pulley and from what I have heard it can be a real pain. I was just trying to avoid that. Ive done the vice grip on the cam gear trick and have never been comfortable with it. On a interference engine, not worth the risk IMO. I can time a 2.2 in less then 5 min... even if it only takes a hour to time the neon its gonna be a pain compared to that! lol.

[turbovanman²]

Use a paint pen and mark the gears and belt so you can put it back in exactly the same spot, will save you hours of time.

[Shadowv4l]

a crank damper puller works wonders for pulling the crank damper off.