Persistent 3.1/3.4 timing cover leak

[Sunaj]

I’ve changed gaskets twice now for the 3.4/3.1. I say them both because I noticed the block says 3.4 on it yet the top engine cover says 3100. 2000 Chevy Malibu. Seems to have a hacked together junkyard motor.

This will be my third time changing the timing cover gasket.. It keeps leaking and I have no idea why and I’m running out of money to service this thing. I made sure all of old gasket is off. I flushed my coolant system. During the flush I had no leak, refilled with premixed solution and now all of it has dripped out? I’m confused..

Any tips on sealing this thing up??? Do I need to put rtv on the front and back of gasket? The instructions only say to put a sticky adhesive on the back where it mates to the block

Topic

[Billy]

So… you haven’t mentioned what you’re leaking. If you’re leaking oil, you did something wrong sealing the timing cover. If, as I gather from the discussion of the coolant flush, you’re leaking coolant, you need to replace your water pump. The timing cover has a weep hole to allow coolant to drain when the water pump leaks. If the timing cover held in the coolant that leaked from the water pump, it would put it into the oil, which would be a Bad Thing.

[Sunaj]

Cool. And yea coolant.

What happens in this scenario? Internal seal gone bad? Is there a way for me to test this? This is a first a pump has failed on me in such a fashion.

[mckrishes]

You could do a pressure test, but it seems apparent as to what the problem is. Just change it and be done with it.

[zero]

An adhesive is used for ease of install, so the gasket stays in place while you’re installing the second part. Usually a dab of anything sticky enough to hold it in place and handy. Like a couple dabs of appropriate silicone or the like.

Take a step back and re-evaluate the problem at hand before you throw more time and money at it.

https://www.ericthecarguy.com/faq/finding-and-fixing-leaks/finding-coolant-leaks

[Billy]

There are two main ways the water pump can leak:
1. From the gasket around its flange
2. From the seal around the impeller shaft
In this situation, it’s generally best to assume that the shaft seal is gone. If you’ve gone to the trouble of pulling the timing chain, just replace the pump. You don’t want to have to do it again.

[James]

The water pump on this engine is not behind the timing cover as in a belt system. My questions is unless he is seeing a drip down behind the water pump, why would there be leaking of coolant into the timing cover to leak out of it?

[Billy]

My mistake, from the discussion of coolant in the timing cover I jumped to the conclusion that this was a chain-driven water pump. I see now it’s on the serpentine belt. Apologies for confusing the matter.

OP, does the water pump have any long bolts going through the timing cover into the block? I’ve seen timing covers get corroded around the holes for these bolts so no amount of sealing will prevent the coolant leaking.

Can you see exactly where the coolant is coming out?

Places to look:
Between water pump & timing cover
Between timing cover & block
By bolt heads on water pump flange
Edge of intake gasket near top of timing cover

[James]

This water pump is the propeller insert style that bolts in with 5 or 6 short bolts into the housing that is not typically changed. I cannot speak for the water pump housing as I have not had to change that yet. Lastly, these engines are notorious for intake gasket leaks. Best of luck.

[Sunaj]

Thanks for the clarification Johnson. The coolant is coming directly from the two water jackets on the Block behind the timing cover. I changed it again ( gasket) this time- as instructed- I put sealant on front and rear of gasket. That’s the only step that I omitted due to lack of funds at the time . We shall see. If this thing leaks again…….

[James]

If it is leaking out of water jackets into timing area, you will want to fix the leak of the water jackets.?. Not just replace timing cover gasket with RTV added or you will risk mixing coolant with oil robbing lubrication.

[Sunaj]

I can only refer to whatever resources I have available. And this case the Haynes manual calls for sealant on both sides of the gasket. A step which I skipped over twice. The timing cover did not leak prior to head and intake gasket change so I take it this is user error. I couldn’t find any cracks or anything around the water jackets and the timing cover itself looks fine

[James]

Please for give me Sunaj, not trying to be pest. If you have coolant leaking out of the timing cover, I am trying to understand where it is coming from. Does your timing gasket cover also seal a water jacket. You definitely do not want coolant leaking and sealed in with timing chain. Although Haynes maybe the only current resource, it definitely may not be the best.

Or is it oil leaking out of timing cover?

Either way best of luck. Hope it works for you.

[Sunaj]

Hey man you’re not being a pest. I’m pretty new at this stuff so ask me as many questions as you need to. It’s leaking from behind the timing cover. There are two coolant jackets on the Block and two on the cover to interface with those jackets. Coolant was gushing from those two jackets.

Those two big circles on the Block are the jackets.. Where the cover meets the block.

Random pic of a guy with my block type.

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[James]

Ok, that makes more since on sealing the gasket. Thanks for picture. I was trying to figure out how coolant was by you timing chain. Thanks for pic. I have a 3.1 but thankfully have not had to do timing chain as of yet. I did have to do the pain in the rear intake gasket. Not hard, just tedious. Best of luck

[Sunaj]

Do you know why there are even water passages there to begin with? If coolant doesn’t flow through the cover why are they even there? Csn i out freeze plugs right there? Maybe im misunderstanding how coolant flows in this engine

[Author]

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