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Has anyone here replaced their own valve seals? I suspect mine are bad and I'm wondering how hard they are to get at on this I6 motor? I've replaced valve seals on a SBC before with the heads on the car. I'm assuming it can be done this way on the I6 as well. Do the cams have to be removed?
 

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2003 chevy trailblazer_ls
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Welcome to the forum. I cannot answer your question and I do not remember this coming up in the past. I am sure someone will chime in and give you an answer.
 

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Thanks, I've actually been a member of this site for quite awhile, but have never needed to post because I've been able to find all my answers to this point by searching.

It doesn't look like leaking valve seals are all too common, but my truck went from using no oil to using quite a bit. I get a nice puff of smoke just after start-up and it continues for about half a minute after start-up. No coolant loss. No external leaks.

I saw someone post about the heads having issues with the valve guides, but I think that was 04+ from what the poster indicated. 140,000 km's on the truck and oil changes done every 5k.
 

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2009 non_gmt360 other
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It's a DOHC design, so both cams would have to come off.

The tricky part is if you want to leave the head on the engine. Then you'd have to jam something (i.e. rope) through the spark plug hole to prevent the valves from falling through the guides.
 

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You ran a compresson test? The puff of smoke on startup could be going away due to the cat warming up and burning off the oil. What do the plugs look like?
 

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2004 chevy trailblazer_lt
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I get a nice puff of smoke just after start-up and it continues for about half a minute after start-up. No coolant loss. No external leaks.
These are EXACTLY the symptoms for leaking valve seals.

If you want to tackle it, it is about 8 hours work. The correct way is to use air through the cylinders to keep the valves in pace.

Here is the procedure:

1) Remove the cam cover.
2) Remove the spark plugs.
3) Remove the exhaust and the intake sprocket bolts.
4) Install the J 44222 onto the cylinder head in order to keep from disturbing the timing chain components.
5) Adjust the 2 horizontal bolts into the camshaft sprockets to maintain chain tension.
6) Carefully move the sprockets with the timing chain, off of the camshafts.
7) Remove the camshaft cap bolts.

Important: Place the camshaft caps in a rack to ensure the caps are installed in the same location from which they were removed.

8) Remove the camshaft caps.
9) Remove the camshafts.
10) Using a suitable adapter, apply air pressure to the cylinder.
11) Install the J 44228 and compress the valve
12) Remove the valve keys.
13) Remove the J 44228.
14) Remove the valve spring retainer and the valve
15) Use the J 38320 and remove the seals.
16) Clean and inspect the cylinder head.

Installation Procedure

Important: Lubricate the valve stems with clean engine oil before installing.

1) Use the J 33820 to install the valve seals. There is only one size seal.
2) Install the valve spring and the valve spring retainer.
3) Use the J 44228 and compress the valve springs.
4) Install the valve keys.
5) Remove the J 44228.
6) Remove the air pressure to the cylinder.
7) Coat the camshaft journals, the camshaft journal thrust face, and the camshaft lobes with clean engine oil.
8) Install the camshafts to their original position.

NOTICE: Refer to Fastener Notice in Service Precautions.
Install the camshaft caps onto their original journal. Tighten the camshaft cap bolts to 12 Nm (106 inch lbs.) .

9) Carefully move the camshaft sprockets back onto the camshafts and remove the J 44222.
10) Install the intake camshaft sprocket washer and the bolt, and the exhaust camshaft actuator bolt.
11) Tighten the intake camshaft sprocket bolt the first pass to 20 Nm (15 ft. lbs.) .
12) Use the J 36660-A to tighten the intake camshaft sprocket bolt the final pass and additional 100°.
13) Tighten the exhaust camshaft actuator bolt the first pass to 25 Nm (18 ft. lbs.) .
14) Use the J 36660-A to tighten the exhaust camshaft actuator bolt a final pass an additional 135°.
15) Install the spark plugs.
16) Install the camshaft cover.
 

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Keep in mind, with everything as it is in these directions, the head must be off the engine and out of the car. Totally correct, except if it's out of the car and on a workbench, you don't need air to keep the valves in place. A pneumatic valve tool would have an adjustable piece to keep the valve from moving while it compresses the spring.

Some engines use goofy seals that have the spring seats attached, it's kind of like a one-piece deal. Most likely, you will not run into these.

Remove the old seals CAREFULLY. If you don't have a seal removal tool, your next likely choice is a pair pliers or vise grips. Use them wisely, you don't want to damage the top of the guides.

Too much information yet??? :bonk:
 

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Discussion Starter #8
4) Install the J 44222 onto the cylinder head in order to keep from disturbing the timing chain components.
5) Adjust the 2 horizontal bolts into the camshaft sprockets to maintain chain tension.


11) Tighten the intake camshaft sprocket bolt the first pass to 20 Nm (15 ft. lbs.) .
12) Use the J 36660-A to tighten the intake camshaft sprocket bolt the final pass and additional 100°.
13) Tighten the exhaust camshaft actuator bolt the first pass to 25 Nm (18 ft. lbs.) .
14) Use the J 36660-A to tighten the exhaust camshaft actuator bolt a final pass an additional 135°.
Hmm. Pretty much what I was expecting. Gotta love GM and their 'J' tools. I'm wondering if I can pull the same trick I do with doing Honda heads and zip-tie the cam gears to the chain/belt instead of trying to locate that J tool.

As for the two bolts needing the tool J 36660-A, I'm assuming thats just an angle indicator. But that indicates the bolts are torque-to-yield and should be replaced instead of re-used.

All and all, seems like a good afternoon project. Gotta see if I can make a cylinder air fitting out of an old spark plug and an air tool fitting...

I got a price of $180 for the seals from a local parts supplier... Seems pricey. Going to call the dealer tomorrow.
 
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