Timing cover leak. To fix or not to fix?

[onion]

I have a '94 Corsica with 156,000 miles. I've fixed lots of stuff on it over the years (including the intake gaskets)- most of it properly. The car runs good, everything works, gets good mileage, and is probably good for at least another 50k- possibly more.

I noticed a small antifreeze puddle near the passenger side wheel today. Looked around, cleaned things off real good, drove it, let it cool down, checking occasionally. I've finally determined that the coolant leak is coming from the timing cover gasket- it's a fairly slow leak, but enough to leave a 6" diameter wet spot on the concrete after sitting overnight.

There's very little room on the passenger side of this engine- is there enough room to remove this timing cover?

Looks to me like all the accessories have to be removed, then support the engine, remove motor mounts, tensioner, and vibration dampener, then the cover will come out. Have I left anything out?

If I choose to remove the cover, I'll go ahead and replace the timing chain. Any tricks to this?

What about the joint between the oil pan gasket and this timing cover? Should I just leave the original oil pan gasket in place, put some silicon on it, and put the thing back together? I'm assuming that one need not remove the oil pan to do this job... I sure don't want to.

I've also considered stopleak. I generally avoid the stuff, but I've SEEN the GM tablets work wonders. I'm seriously considering dumping in some of those GM tablets, tightening the front cover bolts, and crossing my fingers. This could defer this job indefinitely... or at least for a few years.

What do ya'll think?

 

[NYEngineer]

I guess try the tablets or Barsleak and if they don't work, fix it. I've done that exact same repair on an Olds Olero... Alero?? It was a long time ago. Is that a similar car? It was very tight, but I did seal it up nice and I did re use the oil pan gasket, just added silicone.

 

[onion]

Yes, that's a very similar car. The corsica is an L-body, and the Alero is an N-body... but I owned an Olds Achieva a few years ago (also an N-body), and the engine compartment was almost identical to the Corsica's.

So thanks for the post. That directly answers two of my questions. And I'm considering doing just what you said with the stopleak.

I'd be interested in any other advice or comments.

 

[Cutehumor]

that sounds like alot of work. for less than 2 bucks at walmart, I would do the bar's leak golden seal powder and tighten the bolts.

 

[Merkava_4]

I'm still trying to figure out how there's coolant coming from the timing chain cover gasket; usually there's engine oil in there.

 

[cmhj]

Quote:

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I'm still trying to figure out how there's coolant coming from the timing chain cover gasket; usually there's engine oil in there.

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Ya' got me a scratchin' my head too.

 

[wantin150]

By chance, would the water pump be located somewhere near where you've noticed the leak?

 

[JTK]

What engine is in this Corsica? The 2.2L or the 3.1L V6? As far as I know, coolant doesn't run through the timing chain cover on the 3.1L. The water pump is mounted hi and out of the way. Not sure on the cam-in-block 2.2L.

Joel

 

[onion]

Put in some GM stopleak pellets this morning. The thing only leaks when the engine is cold... so I won't know until tomorrow morning if these little magic tablets work. But like said... I SAW them perform a miracle once, so I'm expecting good results.

Originally Posted By: Merkava_4
Try Valvoline Maxlife.

Originally Posted By: cmhj
Yeah! Maxlife!

Originally Posted By: wantin150
AutoRx it!

Originally Posted By: JTK
Needs more Moly?

FYI (for ya'll's info.), water running through a cast aluminum timing cover is fairly common. And in this case, it's leaking.

 

[Ramjet Roger]

For what it's worth, I had a timing cover leak on my wife's Dodge Caravan 3.8L v6. Same repair as for your engine. Had the dealer do it under extended warranty ($800 repair). Developed the same leak 13 months later (now out of warranty).

Did the Bar's Stop Leak, the old black stuff. Leak slowed from 1 qt of coolant every 3 months to 1/2 qt per year. I've had UOAs on every oil change for the past 2 years and the coolant contamination in oil has dropped to near normal levels and remained there. I've contemplated doing the repair, but the the Bar's Stop Leak seems to be doing the job.

BTW, my leak only dripped when the engine was really hot and the pressure was highest. A radiator pressure test showed the leaked from the top of the valve cover. Afterwards, no visible leak.

It might work for you.

 

[Merkava_4]

Well, so far what I've gathered from reading this thread is that the coolant routes through the cover and not behind it; I'm glad I got that figured out.

So where's the leak? Is there a pin hole in the cover, or is there a crack in the cover? What material is the cover made of? Cast aluminum?

 

[wiswind]

I had this leak on my '96 3.8L, but it was just a very slight seepage.
I solved the problem with Bar's Stop leak.
I has held for over 5 years....and MANY miles.

The thing that is very important is to verify that it is NOT leaking INTO the engine oil.
You can send a oil sample in for testing to see if any coolant is getting into the oil.

For What it's worth, the FORD replacement gaskets are improved, to avoid the same failure in the future.
The same may be possible for you.

The thing about this major of a repair is that other things can go wrong, in my case, the oil pump and water pump are mounted on the front cover, you also have to mess with the harmonic ballancer, drop the oil pan, which involves dropping the catalytic converters......as you can see.....lots of opportunity for things to go wrong.

I consider the Stop Leak to be a good avenue to try, and very likely to work, if you catch the leak in the early stage.

 

[JTK]

For the lesser talented like myself who were unaware, the water pump casing and associated jacketing is cast into the timing chain cover on the GM 3.x engines. Assuming this post is in regards to a 3.1L, lookie here: http://cgi.ebay.com/ebaymotors/New-Front...sspagenameZWD1V

Joel

 

[Merkava_4]

Quote:
. . .the water pump casing and associated jacketing is cast into the timing chain cover on the GM 3.x engines.


OK. . . now this is all starting to make sense.

 

[onion]

Well GodDanmIt.

Lazy ba$tard that I am... I initially decided not to fix this properly. I dumped in some of the GM stopleak pellets and waited a few days. This stopped the leak at the timing cover... and I'm happy enough about that. I religiously check my oil for signs of coolant, and haven't seen anything to be concerned about.

But I was poking around under the hood with the engine nice and cold, and noticed that my LIM gasket is once again leaking- externally this time. I replaced it about 4 years and 30k miles ago... back before Felpro came out with their new & improved gaskets. I've known for some time that a second failure was eminent, considering that the replacement gaskets were essentially the same as the originals- just wasn't expecting it quite so soon.

So now I have a massive weekend project ahead of me- not immediately (the leaks are very minor, and there's no visible sign of coolant in the oil), but in a few weeks when I have time. I'll go ahead and replace the LIM gaskets with the new Felpro "problem-saver" gaskets, replace the oil pump drive o-ring with the new & improved GM o-ring, and replace the timing chain & front cover gaskets. And I'll upgrade my leaky plastic '94 valve covers to the aluminum '95+ models. I expect this to kill the whole weekend.

I'm quite familiar with the LIM job, having done this to several different 3100 engines. I've done front covers, timing chains, and such on lots of engines over the years, but not on a 3100. Posts so far have answered several of my questions, but here's one more:

Do I need any sort of pullers for the timing chain sprockets?

Also, I've been told that cheap timing chain sets (from Autozone, etc.) don't wear very well. I'll likely buy this from a dealer... but just to satisfy my cheap nature: Is anybody familiar with an aftermarket timing set that's as durable (or more than) the stock chain & sprockets?

 

[wiswind]

In my case, on my '96 3.8L windstar, the stop leak did NOT solve the Lower Intake Manifold leak.....maybe slowed it significanly for a month or so at BEST.
I am Super happy that it solved the timing cover leak though.