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Do I need to replace valve seals?

4K views 12 replies 9 participants last post by  xcaliber81 
#1 ·
Hello, I have a 00' Limited w/ the 4.7. 191k miles. When I first start it up a slight bit of smoke comes from the top left area of the motor and there is a bit of oil leaking there also. After about 5-10 seconds when the engine RPM's go down and it is near operating temp the smoke goes away. You can also smell oil/gas when it smokes upon startup. I am 95% sure that it is the valve seals, but I just want to get a few opinions from more experienced jeep owners before I take it to the shop to get inspected. Thanks!
 
#5 ·
I don't think it is the Valve cover gaskets because the engine doesn't misfire or anything like that. It runs perfectly besides the slight smoke upon startup. Plus I went to autozone (Yeah I know I should have went to a real shop) and the guy that read my codes said that he has owned 3 WJ's and that it has bad valve seals.
 
#6 ·
While you are in there, do the valve seals as well... This will almost eliminate any oil burn/loss you have. Aged valve seats on the valve rods allow oil to push past them resulting in loss. I did my valve seals and valve cover gaskets at the same time. Well worth it! I don't loss oil any more.
 
#7 ·
Worn valve seals wont cause smoking in the engine bay, that's almost certainly a leaking valve COVER gasket. I think you're now also confusing a valve cover gasket with a head gasket. Your valve cover gaskets have no impact on misfires, compression loss, coolant etc.

I wouldn't exactly group valve stem seals in with the "While You're In There" mantra with the valve cover gaskets but i guess you could. Those are two completely different jobs on opposite ends of the difficulty spectrum, though. I know a few people have attempted to change their valve stem seals with the heads still in place and couldn't get the last couple from lack of space. I had my heads out when i did mine and it was easy-peasy, but unless you know the shop very well i wouldn't trust them to actually replace all the seals. I'm betting they'd totally, avoid the last few but say they did them.
 
#9 ·
"I don't think it is the Valve cover gaskets because the engine doesn't misfire or anything like that."
...That statement makes my brain hurt.

I think there's certainly some confusion on how an engine works or what specific parts are called.
Absolutely, but at least he's here and willing to learn. I adamantly believe car owners should be capable of working on their own vehicles and avoid shops whenever possible. To the OP - please don't take your WJ to a shop for a valve cover gasket job, you can do it yourself for less than $30, including beer.
 
#11 ·
It may take a while to learn how to navigate around on the forums and there's a lot of good info in the FAQ's on the homepage near the top.

If indeed you're seeing oil leaking onto the head/motor from the valve cover bottom lip the gasket needs replaced. Here's a good write-up from the FAQ's on changing the valve cover gaskets on the 4.7.

http://www.jeepforum.com/forum/f310/how-replace-valve-cover-gaskets-4-7l-2004-grand-cherokee-limited-2946161/#post27642209

While it's a good idea to change both valve cover gaskets at the same time as you can see the passenger side is more difficult than the driver's side where you say yours in leaking. You could replace the leaking side first then tackle the passenger side when you gain confidence.

You can also search for youtube videos through goggle; "youtube video replacing valve cover gaskets on 2000 4.7 WJ (or Grand Cherokee)". Some are good while others aren't. Good luck.
 
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