Possible coolant leak?

[theunpaidBill]

I checked my oil at lunch and it's clear, but I noticed some dampness along the seam of the head. It doesn't smell like anti-freeze, but honestly my nose isn't great.

I've been looking around the forums and found this post: http://www.saturnfans.com/forums/sho...4&postcount=10

Is this a common issue with the Saturn engines? Should I pop the valve cover and give the head bolts a few more degrees torque? I did the full Oldnuc approved torque process when I put the head on.

Should I just monitor it and see if it's environmental? It's been pretty rainy.

[Waiex191]

I would monitor. The low coolant light will go on well before disaster for a small weep.

[ultravioletnk]

Originally Posted by theunpaidBill

Is this a common issue with the Saturn engines? Should I pop the valve cover and give the head bolts a few more degrees torque? I did the full Oldnuc approved torque process when I put the head on.

Should I just monitor it and see if it's environmental? It's been pretty rainy.

i have read multiple reports of coolant weeping from the seam on the transmission side of the head, however it could also be coming from the coolant temperature sensor or upper radiator hose. did you apply thread sealant to the threads of the temperature sensor when installing it? if not, that would be my prime suspect. if you're confident you got the torque values and final angle correct, i would not tighten the head bolts further.

[theunpaidBill]

Well I'm pretty sure it's seeping between the head and the block. The edge of the top face of the block I can see behind the exhaust manifold is damp when I check it in the morning. I have seen some damp spots under it, so I think it's worse when it's hot and under pressure. It's not losing much but it's there. I think this weekend I'll pop the valve cover and see if I can get anything on the head bolts without taking the cams out. I figure I don't have a lot to lose if I give them all an extra bit of torque.

[billr]

With the "torque to yield" design of those screws, you may actually reduce clamping load on the gasket if you fuss with them; may increase the leak (or worse) and cause more serious problems. Either take the head off and do the job right, or leave all as-is.

[Waiex191]

I would not re-torque them. What's that stuff OldNuc recommended for coolant leaks? Bars leak or something?

The important thing with the head installation is keeping the combustion gasses in the cylinder. Not that we want coolant leaks.

Edit:
http://www.saturnfans.com/forums/sho...13&postcount=4

This was for a coolant leak from the head.

[billr]

I suppose I should remind us all that aluminum castings are prone to porosity that allows leakage right through the metal; the gasket may not be leaking at all, and no amount of torque on the screws can cure the leak. Those tablets are intended to seal the porosity.

PS: Need I say it? The same applies to oil/fluid leaks from the trans or valve-cover area. Some leaks just have to be tolerated unless you want to get the castings vacuum-impregnated to seal porosity.

[theunpaidBill]

Originally Posted by billr

I suppose I should remind us all that aluminum castings are prone to porosity that allows leakage right through the metal; the gasket may not be leaking at all, and no amount of torque on the screws can cure the leak. Those tablets are intended to seal the porosity.

PS: Need I say it? The same applies to oil/fluid leaks from the trans or valve-cover area. Some leaks just have to be tolerated unless you want to get the castings vacuum-impregnated to seal porosity.

This is an excellent point, and I was not aware of it. The head got a bath and a valve job so any sealant that might have been in it is long gone.

Why are the tablets preferred over the other stuff? Bar Leak makes a lot of products.

[billr]

Want a guess? The tablets dissolve to a fluid that can get into the fine porosity and seal by reacting with the aluminum and forming some kind of aluminum oxide/salt in the pores, without risk of plugging larger passages such as in radiator/heater cores. The other products are more fibrous and plug larger leaks by mechanical action, like a beaver's dam; leaks that the tablets can't handle. If it actually is a leaking gasket, then the non-tablet product would probably work better. As a "Hail Mary play", I don't think using both would hurt anything!

[Waiex191]

My vote is the OldNuc advise. They used the Bars leaks tablets at the factory, if you believe the knowledge he imparted.

Using both seems like a bad idea to me. Go with the minimum - two tablets crushed up and dumped in the reservoir.

[theunpaidBill]

I picked up the tablets tonight on the way home. I'm going to put them in tomorrow before I drive to work. That should give them a nice long time to get dissolved and do their job.

[ultravioletnk]

Originally Posted by billr

With the "torque to yield" design of those screws, you may actually reduce clamping load on the gasket if you fuss with them; may increase the leak (or worse) and cause more serious problems. Either take the head off and do the job right, or leave all as-is.

i think the whole "torque to yield" thing is a bit overblown, all bolts begin to yield at a certain load and i think too much fuss is made about how "different" the tty bolts supposedly are. that said, i agree that once you've done the initial torque sequence, it's not a good idea to go playing with the bolts unless you are removing the head. the initial torque values should provide plenty of clamping force.

Originally Posted by Waiex191

My vote is the OldNuc advise. They used the Bars leaks tablets at the factory, if you believe the knowledge he imparted.

Using both seems like a bad idea to me. Go with the minimum - two tablets crushed up and dumped in the reservoir.

i considered suggesting those tablets, but it just rubs me the wrong way to put any kind of particulate/contaminant in the coolant system intentionally. that said, they will probably solve the coolant weeping.

[theunpaidBill]

2 tablets of Bar's Leak OEM and a week of driving and I'm cautiously optimistic that we have that cured. I checked it when I got gas at lunch and I see no signs of seepage and the coolant tank is full.

Now I have to figure out the P0440 code. It's always something.

[TomM96]

At my local Saturn dealership, the parts man looked me in the eye
and said ... TWO tabs, at each time you fill the cooling system.

There's a purveyor of diesel engine components in Minnesota, who
uses them in engines with cast iron heads on cast iron blocks.

GM originally developed these for the cast aluminum blocks first deployed on the Cadillac NorthStar engines, then on Saturns, etc.

The last batch I bought has instructions-
"For all automobile cooling systems. * * Use 1 to 1.5 grams of sealant for each quart of coolant system volume."
These newer blisterpacks contents= 5, 4-gram tablets.
ACDelco 10-108 12378255

The coolant mixture should remain full of the particulate --
If it clarifies, that invites leakage.

[theunpaidBill]

This is the first time I've put some in, but I'm going to remember them.

My P0440 turned out to be easy, the gas cap gasket was crumbling and had more cracks than a nuthouse.

[TomM96]

> This is the first time I've put some in,....

On my '97, the coolant looked the same always after the initial fill
(and after re-flush & fill when the radiator valve disintegrated).

On my 2000 (got 4 years ago with 166kMi) the coolant has always been weird.

Just recently (began small leak last fall) I figured out what was happening:
The leak filters the coolant, so that a fill begins with lots of suspended
particulates from the coolant seal tabs, but over time, the particulates disappear, and the fluid mix gradually clarifies. So for this engine I may
have to add tablets like medicine, at intervals.

I just got a junkyard head slightly rebuilt; a new head gasket should
improve the situation.

* * * *
Both my used Saturns needed new gas caps!