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3.8 Timing Cover Gasket Replacement

S

SergheiS

New member
So I've had the timing cover on my 3.8 Camaro (not a W-body, but same engine) leak coolant around the water pump, and I now plan to replace the gasket as it is leaking more and more. I've tried to replace the timing cover gasket before in the past, but I am still uncertain if I had done something wrong or the engine had already been fried out (The engine had rod knock when I tried to replace the timing cover). In the past after the replacement I've had coolant appear in the oil after redoing the timing cover twice, so I just wanted to ask what the proper way to replace this gasket is.
Just a few questions,
-Black RTV on all bolts?
-Should the gasket itself be covered in any sealant, or just dry gasket?
-I've been looking for the harmonic balancer bolt and couldn't find it anywhere, I know it is said to be torque-to-spec, so if I reuse the old one, what could happen?
-Any other pointers?
 


did you use thread sealant on the cover bolts and 4 long w/p bolts, a lot of them go right into the coolant jackets of the block.
 
Scottydoggs said:
did you use thread sealant on the cover bolts and 4 long w/p bolts, a lot of them go right into the coolant jackets of the block.
Click to expand...

This is a used engine I got, I didn't touch anything but the intake and oil pan on it when I put it in. On my old engine, no, sealant was not used on the bolts.

The one thing that really confuses me is the fact that I had coolant in my oil within seconds of startup after redoing it twice on an old motor. Is there any way this could've happened by sheer error in the timing cover replacement?
 


Scottydoggs said:
if you pulled the lim coolant can dump in the oil.
Click to expand...


I probably explained this terribly, let me start over...

Some time back, I had a 3800 motor develop rod knock. I am still unsure/don't remember if the oil I drained from that already had coolant or not, but regardless, I tried the old "replace rod bearings through oil pan" trick. At the same time, I tried to replace the oil pump. Immediately after startup, the oil was filled with coolant. I only ran it for about 20 seconds. I redid the timing cover, same thing happened. First time: Dry gasket. Second time: Reused gasket but covered in black RTV. Same result. No RTV on bolts.

I got a replacement motor which was FWD, so I had to replace the upper and lower intake and oil pan. I did not touch the timing cover on this motor as I wasn't sure if I was going to mess it up more (despite the instructions saying to replace every gasket). It has had zero issues so far, however, I had recently noticed the coolant leak at the timing cover. I want to fix it, but the past experience with the timing cover makes me cringe, as I am still uncertain about where I went wrong, or if the motor was truly shot already.

So I am wondering, dry gasket or RTV it, and black RTV on bolts? And any other pointers/hints? I'm trying to get this down to the detail to prevent any possible errors.
 
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being these are na engines theres a chance it came from the lim when you pulled it, or the upper had failed already and was leaking into the oil and you saved it. any time a lim change is done a oil change should follow before you start it up.

you rtv both sides of the gasket for the cover 2 inches up from the pan up and along the oil pan.

the cover bolts use plumbers thread sealant. like this. any brand with ptfe works well.

Z_uC3uicpEx_.JPG
 
Scottydoggs said:
being these are na engines theres a chance it came from the lim when you pulled it, or the upper had failed already and was leaking into the oil and you saved it. any time a lim change is done a oil change should follow before you start it up.

you rtv both sides of the gasket for the cover 2 inches up from the pan up and along the oil pan.

the cover bolts use plumbers thread sealant. like this. any brand with ptfe works well.

Z_uC3uicpEx_.JPG
Click to expand...



What kind of RTV should I use for the gasket? Black, blue?

Also, would black RTV work for the bolts, or it must be specifically the one shown?

And just to make sure, so there is no way that the timing cover alone can mix coolant and oil? Would there have to be something else wrong with the engine, or is it possible to mess up the timing cover and get this result?

One thing I'm not sure if I'm clarifying correctly: I am talking about 2 different engines here, one of which was the old one and one is the new one. My old one I had the LIM done by a mechanic but it had no issues with coolant/oil mixing.

My replacement engine which was a new block, I personally did the intake and have zero issues. The only thing now is that the timing cover leaks coolant externally and because I wasn't sure where I went wrong on the previous block, I am not sure how to tackle the job.
 
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So before I start, I just want to confirm... like I said, last time I tried this on another motor I ended up with coolant in oil, so I'm wondering, if this gasket is done wrong, can coolant enter the oil instantly?
 
you should be ok, drain the engine of coolant best you can pull the lower rad hose off the cover, pull the dog bones and rock the engine back and fourth. then you'll see coolant come out the cover bolts as they are removed till the coolant is drained out the hole.
 
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