Valve stem seal replacement without removing head?

[2002dude]

Is this possible?  I am starting a restoration and the motor is in good shape, just has dry valve stem seals. I tried searching but couldn’t find much on the topic. 

[JsnPpp]

I may also pursue this. I did some searches a bit back and didn't find anything conclusive.

 

I don't mind pulling the head but I assume that if you pull a head you should have it decked. I prefer not to get it decked any more times than I need to. Unless thats not req'd then...

 

Jason

[dlacey]

I cant believe its possible... to change the seal you need to remove the valve spring...to access the valve spring you need to remove the rocker arm...to remove the rocker arm you need to withdraw the cam... then maybe the rockers can be swung out of the way...or more likely you need to drive out the rocker shafts...that needs access to back of head and room to withdraw the shafts....i cant see how.

I've done it on a jag V12 where the cam comes up & out and the cam followers lift away...but with M10 rockers and the need to pull cams & shafts out the end...it cannot be...

[kbmb02]

2 hours ago, JsnPpp said:

I don't mind pulling the head but I assume that if you pull a head you should have it decked. I prefer not to get it decked any more times than I need to. Unless thats not req'd then...

 

In my experience, it’s not mandatory to surface/deck the head when removed… of course, do it if needed. -KB

 

[JsnPpp]

9 minutes ago, kbmb02 said:

 

In my experience, it’s not mandatory to surface/deck the head when removed… of course, do it if needed. -KB

 

 

Good to know! Thank you.

[TobyB]

If you have rocker locks, you MIGHT be able to pull it off. 

With the rocker retention springs, I don't think you can get

the rockers far enough out of the way.  

 

Compressed air or rope works to hold the valve up.

 

But honestly, taking the head off is NOT that big a deal, and I agree with Ken-

if the old head gasket looks good, and the head and block surfaces clean up well

and are straight, there's no reason to surface anything.

 

t

 

[Mike Self]

1 hour ago, TobyB said:

taking the head off is NOT that big a deal

A trick I used to make sure I didn't disturb the valve timing when removing the head was to unbolt the camshaft's timing chain sprocket from the cam before I removed the head.  I then ran a loop of wire around the chain at the sprocket's 6 o'clock position to make sure chain and sprocket didn't move in relation to each other.  Finally I bungee corded the sprocket to the upper edge of the open hood (after propping the hood open with a broomstick to prevent accidental closing).

 

Since the sprocket will bolt onto the cam in one one way, simply align the cam's bolt holes with the sprockets, and reassemble once the head's back on.

 

mike

[Son of Marty]

Just to add, to remove the rocker shafts you'd need to first remove the head bolts and at that point whats stopping you from removing it anyway? If your not using the old Tii cutter ring head gasket then resurfacing is not needed if all else is up to snuff. I've never hung the timing chain because you can't rotate the engine to clean the pistons and remove the usual swarf from cleaning the old gasket off, you should be able to find TDC with the head off.

[tzei]

Way way less hassle to just take the head off. 

[2002dude]

Thats guys. I just pulled my valve cover to and see what you mean. Dang it, if the head comes off i’m going to have to get a 284° cam. This news is going to add a lot of cost to my $10 valve stem seal job. 

On another note, the engine has a single row timing chain. Is that normal?

 

[Son of Marty]

Single row chain is a sign of a rebuild or atleast a chain replacement all 2002 had a double row chain. Imo if your going to spring for a new/regrind cam skip the 284 and go for the 292.

[2002dude]

40 minutes ago, Son of Marty said:

Single row chain is a sign of a rebuild or atleast a chain replacement all 2002 had a double row chain. Imo if your going to spring for a new/regrind cam skip the 284 and go for the 292.

 
I was looking at the IE new 284. It says the 292 is for side drafts, over 6500 rpm and requires valve clearance checked. Thats seems more involved than im capable of?  Is the 292 really worth the trouble? Good on a street car with a 38/38?

[jimk]

Has it been said if this is a 2 liter 02 engine or an E21 engine or a 318 engine?  That's a clue on the chain.

[TobyB]

12 hours ago, 2002dude said:

 
I was looking at the IE new 284. It says the 292 is for side drafts, over 6500 rpm and requires valve clearance checked. Thats seems more involved than im capable of?  Is the 292 really worth the trouble? Good on a street car with a 38/38?

 

Yeah, don't believe everything you read on the internet.   'checking clearance' can be done with

some play doh (but plasticene works better) and takes half an hour at most,

 and the 292 idles well and pulls hard.  

It's about ideal for a 38/38.

 

Jim makes a very good point, though- most M10s have double row chains.  The ones that

don't are usually 1.8 liters. You can tell by the largish number cast into the head on the intake

side- it's obscured by the intake, but visible if you clean things a bit.  BMW rebuilt 2L engines

often used the single row, but likewise, I've never seen a 2L that came from the factory that way.

 

t

 

 

[thehackmechanic]

Someone would make a lot of money if they developed a tool, or a spray-on valve seal, or something, that would let you do this, but I don't think I've ever read of a workable method.

 

And the problem is that with the head off, you go right down that rabbit hole where you convince yourself that you might as well have it crack-checked, which means hot-tanked, and if you're going to do THAT, sheesh, why NOT have it skimmed, and geez Louise, are you REALLY going to disassemble the valve train and replace the valve seals and NOT do a valve job,  and NOT have a machinist tell you if your valve guides are within spec?

 

I think that, if you're really trying to conserve money (and lord knows we all understand that), the best you can do is the troika of a compression test, a leakdown test, and a coolant exhaust gas test to give you the best evidence that there's nothing else wrong and you can just disassemble the valve train, change the seals, reassemble it, and drop the head back on. But as my friend Lindsey Brown, shop foreman at The Little Foreign Car Garage in Waltham, says, "Never pull a head off a car unless you're prepared to deal with whatever you find."

 

For all those reasons, 2002s that run well except for doing the James Bond oil fog thing when you let off the gas tend to stay that way until they need other engine work.

 

--Rob