Just recently purchased an 02 3.7L Liberty. Had a blown hg, so i pulled the motor and had the heads sent off to get checked out. Right head was cracked and left side was warped. After resurfacing the left head and doing research, I decided to just replace both heads, so that i wouldn't have any issues with valve seat dropping. Now just curious if anyone has any experience with the ebay gasket kits, mainly looking at the sealtek or mizumo auto. They seem to be the more popular kits. Also if anyone has any issues with the timing chains from ebay.
Replacing heads gasket question
- Thread starter 2jgs300
- Start date
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The factory head gaskets are muti layer steel (MLS) but I would go for graphite as they are more forgiving and give a better seal where surfaces may not be to spec for MLS gaskets. MLS gaskets require a 30RA finish for a good seal which your heads should have after they are resurfaced but your block won't unless you had that resurfaced which i'm guessing wont be. You could also use copper gasket spray on each side of gasket to ensure that much better of a seal. Did you buy new heads or just have both original heads resurfaced? My feelings are you'd be perfectly fine purchasing your gaskets and timing chain set on Ebay. I've always had good luck with Mizumo for timing belts kits and water pumps. How many miles are on your Jeep would determine weather you should replace your oil pump for peace of mind but I would say throw a new water pump on the list for sure. Did you overheat the engine?
Bought new heads just to avoid worrying about the valve seats dropping. I purchased the Jeep cause the previous owner didn't want to mess with h/g issue. Wasn't sure how hot the motor got until the machine shop said one head was cracked and the other was warped. Also just replacing the oil and water pump for peace of mind, might as well cause the motor is already out. It has a little over 100k so I'm going to replace all the gaskets as well. Just curious cause i've read good and bad reviews, but nothing clear cut one way or the other.
rbtconsultants
Full Access Member
The ebay MLS gaskets I got seemed like the coating was thin, almost like paint or e-coat. Felpro gaskets have a Viton rubber coating to better tolerate surface imperfections. The difference is obvious. However, the ebay gasket worked fine I believe. I still have the ebay gasket on one head. Compression and leakdown is good. Engine ran fine with it. The other head had to come back off because it turned out to be cracked from the rebuilder (god apparently hates my jeep). It's going back on with the Felpro gasket.
I don't think there is any reason you should worry about the block surface unless it got scratched up removing the head or otherwise got visibly damaged. There is no reason why it would suddenly not have a good enough surface for the mls gasket. The block surface for the one head that is still installed with the Ebay gasket was cleaned up with just 3m gasket remover and plastic razor blades. For the reinstall of the other head I used yellow Roloc bristle disc to clean it up. I'm being very cautious doing the second head because because I'm sick of putting it on. This is my third time putting it on. Reinstalled once because I thought my gasket and surface prep were bad. Coolant in cylinder #1. Turns out the head was bad.
I used a new timing set from evergreen, got it on Amazon. Seems to be good. The fit of the cam sprocket was very tight. I used the bolt to press it on. Turns out if you do that you should remove the bolt and make sure the alignment nub on the cam is in the sprocket keyhole slot properly. If not the sprocket is not all the way on and that can result in the timing slipping. Ask me how I know.
Pro tip: 3m gasket remover will remove carbon from piston tops and make them look like new.
Bob
I don't think there is any reason you should worry about the block surface unless it got scratched up removing the head or otherwise got visibly damaged. There is no reason why it would suddenly not have a good enough surface for the mls gasket. The block surface for the one head that is still installed with the Ebay gasket was cleaned up with just 3m gasket remover and plastic razor blades. For the reinstall of the other head I used yellow Roloc bristle disc to clean it up. I'm being very cautious doing the second head because because I'm sick of putting it on. This is my third time putting it on. Reinstalled once because I thought my gasket and surface prep were bad. Coolant in cylinder #1. Turns out the head was bad.
I used a new timing set from evergreen, got it on Amazon. Seems to be good. The fit of the cam sprocket was very tight. I used the bolt to press it on. Turns out if you do that you should remove the bolt and make sure the alignment nub on the cam is in the sprocket keyhole slot properly. If not the sprocket is not all the way on and that can result in the timing slipping. Ask me how I know.
Pro tip: 3m gasket remover will remove carbon from piston tops and make them look like new.
Bob
Sorry to hear about all of your issues. I'm not worried so much about the surfaces, as much as i am worried about the graphite head gasket holding up. Have always used mls gaskets, so i'm not very familiar with graphite gaskets. Found a pretty good price on the timing chain kit w/ oil and water pump.
Graphite gaskets are also known as composite gaskets. Alot of exhaust gaskets are composite. They are usually used on engines with aluminum heads and a cast iron block because they can better deal with the difference in expansion between the 2 metals. Our 3.7's have cast block and aluminum heads and who knows, may have seen a lot less head gasket fauilres on these engines if they were installed from factory. Definitely use Fel pro if you choose MLS gaskets. Google MLS vs graphite head gasket and you'll find great info on the subject to better help your decision.
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