coolant leak - not elbows or intake gasket?

[upmichigan]

Hi
I am working on my son's 07 GP standard 3.8. We have been through the bypass elbow failure and replaced them with aluminum about 2yrs ago. A few months ago, he started losing a little coolant and I purchased a water pump and another set of elbows just in case. The small leak just became a huge leak and I replaced the pump and elbows again. This did not help.

The leak is continuous down the passenger side of the motor (w/o car running - I should have looked closer before starting the replacement of the pump and elbows...). If you are looking at the water pump, it starts in the area behind the part of the casting that the water pump bolts to, behind the area that the radiator hose connects to. If I stuff a rag in this area from the bottom, it becomes saturated. If I stuff a rag in the cavity below the intake manifold (below the bypass elbow), but above the water pump, it stays dry. I'm assuming this means no leaks from lower manifold or elbow.

Any suggestions?

Thanks.

[Fivefingerdeathpunch]

Front cover maybe?

[upmichigan]

Front cover maybe?

That's what I was thinking, but I don't see that coming up as a common problem. Has anyone seen this? Car has 180k and burns no oil, runs great otherwise. Looks like a big job to fix?

[Fivefingerdeathpunch]

I've seen the little gaskets fails that the bolt between the iron block and front cover/water pump housing.

[bonerjamz03]

Did you use sealant on the water pump bolts?

[upmichigan]

I've seen the little gaskets fails that the bolt between the iron block and front cover/water pump housing.

That's what it looks like. I plugged the overflow tube off of the radiator and put air in it. You could see bubbling coming out of the edge of the front cover basically behind the water pump. I'm assuming this needs to be fixed by pulling the engine?

Looking for opinions on what to do with the car: 07 with 180k miles. Decent body, not perfect. Just replaced front-end (wheel bearings, whole lower control arm assy, tie rod ends, struts) new breaks, exhaust, tires. Was hoping this was going to last him through college. We did most of the work ourselves, so we have about $5k invested (including what we paid for the car about 2 years ago). However, this fix is out of my league I think. Fix it or sell it as-is (maybe get $500.00 for it?).

Thanks for the comments so far. Any suggestions are appreciated.

[BillBoost37]

The fix is about $10 in gaskets, time and some coolant.

[upmichigan]

The fix is about $10 in gaskets, time and some coolant.

Any idea how much time (average mechanic, not me)?

[Turbocharged400sbc]

make sure that the tiny bolt is sealed with sealer and tight, in the middle of the iron block surface below that radiator hose connection.

[mkyota1]

Any idea how much time (average mechanic, not me)?

If you have to pay a shop it would be a lot. It calls for around 6.5 hours labor to do the timing cover gasket. If you can't figure it out it might be worth having a shop look at it to pinpoint the leak. It is possible that it is the cover but more likely something else.

[upmichigan]

Long story - but it is the timing chain cover. I will update later when fixed in case anyone is interested. Thanks to all that replied.

[upmichigan]

So with the wealth of information on this site, I was able to remove the cover myself and verify the failed gasket. I have a new gasket set and I have a few questions that I couldn't answer by searching this site (maybe I didn't phrase it right, etc..):

1. Do I use any RTV on the cover gasket?
2. Torque rating on all cover bolts?
3. Anyone have a trick to removing the gasket off of the block?

Also, in case someone is looking at doing this job, Autozone in my location has the HB puller AND the GM 3.8 adaptor kit available for free rental. Only thing, I had to roll the pointed end piece of the puller (forgot what that's called) on a grinder just a bit to get it's diameter down to fit inside the HB. Otherwise it was jamming up and just pushing on the HB.

Again - thanks to all of the helpful individuals on this forum.

[Fivefingerdeathpunch]

Razor blade works good or a 3m rubber bristle disc on a die grinder.

I don't know the tq spec but I always just do snug/tight. Criss cross pattern.

[Scottydoggs]

i like to lay rags in the valley to catch any crap that comes off from the razor blade cleaning, then spray with brake cleaner and wipe clean.

same goes for the lim where it meets the heads.

[upmichigan]

Just RTV sealant on the oil pan where it meets the cover?

None on the cover gasket itself?

[Scottydoggs]

timing cover you smear some rtv a 2 inches up from the pan on both sides, (i went up to the locating pin) lay the gasket in, smear some more rtv on the gasket 2 inches up, then smear some on the oil pan gasket. nothing to thick, just a thin smear.

i just made all the bolts good and tight. all but the right side bottom 2 for the crank sensor, those are 13 ft lbs.

i also used thread sealant on the cover bolts, some of them go into the blocks coolant jackets. a little insurance, the 4 long water pump bolts get sealant for sure.

you want to use the sealant on the lim bolts too. same deal water jackets of the heads.

[upmichigan]

timing cover you smear some rtv a 2 inches up from the pan on both sides, (i went up to the locating pin) lay the gasket in, smear some more rtv on the gasket 2 inches up, then smear some on the oil pan gasket. nothing to thick, just a thin smear.

i just made all the bolts good and tight. all but the right side bottom 2 for the crank sensor, those are 13 ft lbs.

i also used thread sealant on the cover bolts, some of them go into the blocks coolant jackets. a little insurance, the 4 long water pump bolts get sealant for sure.

you want to use the sealant on the lim bolts too. same deal water jackets of the heads.

Got it - thanks. However - I'm not seeing an oil pan gasket. Looks like it was just sealed with white/gray sealant instead - sound normal? I'm assuming black RTV is OK here...

Also - do you wait for RTV to cure for any length of time before filling and running?

[Scottydoggs]

you have a 04 up with an al pan? then its just rty, id use the gray. and if the old sealant came off on places id clean it off and use all new there, make sure you seal it well to the block where the old meet new rtv. pretty sure you want a nice bead laid on the pan with a al pan.