The Stovebolt Site Forums The Shop Area Engine Shop Need help found antifreeze pool under valve cover

57 V8 3100 step side pickup. Has a V8 283-350 my engine got replaced somewhere along the line with a 1970 350 trying to look like a 283.

Ok, so I was having a small oil leak in the front of my motor, as you face it on the left (passenger side) front corner where the intake manifold mates with the block at the corner of the rubber gasket and the intake gasket. I think since I am running script valve covers and no PCV out of them it had too much pressure and blew fumes out the oil filler tube breather and when it got plugged blew out this rubber gasket. Or maybe I had too much RTV silicone on that end of the gasket. But it squeezed out that corner.


I went to take the covers and intake off to replace the gaskets and I note there is a couple small pools of anitfreeze under the valve covers!

Crap. I guess I did not get a good seal on the gaskets between the intake and the block.

If I remember correctly I used some tacky sealant to hold them and also coated the water and bolt holes with some RTV of some sort and then assembled and torqued to 30 lbs (or maybe it was 20 do not remember) I have seen noted lately that it should be 30 on a 350.

So I am wondering what I did wrong so I can do it right this time?

Any ideas?

I am going to inspect the gaskets between the intake manifold and the block once I get it lifted off. Hope to see the problem at that point.


The water is nice and green so it is fresh. But the other spots around the lifters all looks like oil. Like in the lifter pockets on top and all.

I am also working on trying to get a better source for the PCV that I was running though a small hole in the intake manifold bolt that held the coil bracket on. I may just tap the back of the valve cover.


Here are some pictures. The 7th and 8th also shows some sign of a bit of sludge buildup around a bolt.

Antifreeze under valve covers


I only have probably like 200 miles on this since I replaced the gaskets last time 2 years ago. And for the last year it has been sitting in the garage as I restored the interior and the engin bay. So it has not been started in like 1 year. Kind of surprised to see the antifreeze in there. Maybe it got fresh antifreeze pushed over there from removing the radiator hoses and pushed it past the gaskets into those areas.

I added some pictures to that same link that shows the gaskets and surfaces on the intake manifold.

Off hand I do not see where it would be leaking antifreeze.

Plus if it leaked fromt he intake manifold it would have to drop into the valey and then get flung up into the valve coverarea through one of those small holes on the end. But if that were the case I think it would have oil mixed with it. Maybe it did and it separated?

Or is it more likely that it is coming up from a leaky head gasket and leaking up a head bolt into the valve cover area?

I gently checked a few head bolts and they seemed tight or at least not loose. No obvious leaks out the side of the head or antifreeze in the valey.

Also the dip stick seems to be clean oil no water.

I also see that it looks like the rubber valley seals were improperly installed over the long intake gaskets. It should be under them and some sealent put in the corner ends where they meet. Being on top instead of under the long gasket is probably why one end squeezed out and caused an issue with oil leaks. That and it got misaligned during install. But had nothing to do with the antifreeze.


But where is the antifreeze leak coming from to put antifreeze under both valve covers?

If it were mine, I would be pulling the heads and sending them to a machine shop to be checked out. If alls well, a good set of head gaskets should fix the problem,
Scott

Have you ever had the heads off? The antifreeze could be comming up past the head bolts, especially if they did not have any sealant applied to them.

That looks like coolant leaking past the head bolts. I like to use a brush-on sealant on the bolt threads and a dab under the head of the bolt. It's possible for coolant to follow the threads and seep under the bolt head even with the right torque on the bolts. Pull the head bolts one at a time, clean them up on a wire wheel buffer, and paint a little sealer on before reinstalling them. You might manage to stop the seep leaks without taking the heads all the way off. I like to use Permatex Super 300.
Jerry

OK thanks for the suggestions.

I have not had the heads off. I bought it in 88 and it is the same motor and build as back then. At the time it was sold to me I was told it was a fairly fresh rebuild. It has been running fine, does not smoke and has good smooth power so I was surprized to see the antifreeze.

Since 1988 I probably have only put about 10,000 on it if that. Most years I do about 200 miles. so 23 years about 5,000 plus a few heavier early years and what ever from the prior owner.

I may try HOTROD LINCOLN's idea of brushing on some sealant to the head bolt threads and under the head and see if that helps and occasionaly pull the valve covers to inspect and monitor the water and oil levels.

If I have to go through the headache of pulling the heads then I might as well have someone look it over good or rebuild it at the same time.


I might see if I can get the local mechanic to look at it and see what he thinks. He has a couple 55-58 V8 chevy PU he uses so he might have some ideas as well.

What type of brush on sealant would you recommend for "brush-on sealant on the bolt threads and a dab under the head of the bolt"?

Permatex Super 300. It's a dark brown, almost black thick liquid sealer that was developed in WW II for use around aviation gasoline. It's a much better sealer than the light brown Permatex 3-D brush-on stuff. It can be a little hard to find at times, but it's worth the search. A 4-ounce bottle will last a very long time.
Jerry

http://www.permatex.com/products/Au...atex_Super_300_Form-A-Gasket_Sealant.htm

Hotrod,

Got a question. How will this help seal around the bolt?
I am thinking the threads just thread into the block and not the head. Only threads on like the bottom 1 inch or so of the bolt that goes into the block. So I would think there would still be a void around the top of the block and the bottom of the head and going up the bolt. Unless I put lots of sealant down the hole before I pushed the bolt down but that sounds like a bad idea.

Or is there just enough that comes up off the threads and surrounds the bottom of the bolt above the block so that it seals the void?

Plus a little under the head of the bolt to help seal any that makes it up past there?

That might work I suppose since the sealant will pool up around the smooth bolt shaft and the bolt hole down the head and the top of the threads that may not make it into the block.

The head bolts screw into the block where the water passages are. That's the only place that the head bolts are exposed to antifreeze. That's why the antifreeze will seep by the threads and up the bolt. The rest of the bolt would be sealed off by the head gasket so that the only place antifreeze can get by would be the threads themselves.

Threads do not have 100% engagement between the male and female parts of them. there's always a few thousandths of clearance to keep them from galling as the bolt is tightened. The sealer fills that void, and the small amount of sealer at the bolt head is just insurance in case any coolant makes it past the thread. The sealer is also a very effective lubricant, allowing all the torque to apply itself to bolt stretch rather than be used up overcoming thread and bolt to cylinder head friction.
Jerry

One more suggestion, http://www.permatex.com/products/Au...ermatex_the_Right_Stuff_Gasket_Maker.htm

This stuff will seal anything, much better then the blue you are using now. At least use the black RTV if you choose not to use the Right Stuff above.

We use this to seal head bolts on the 6.5 liter diesels,
http://www.permatex.com/products/Au...ealants/Permatex_Pipe_Joint_Compound.htm
They have the same problem you do, coolant weeps around the threads, fills the head bolt area and slowly seeps out from under the head into the oil.

If you pull out a few head bolts and find them rusty and cruddy, you might be thinking about pulling the head for a clean up. The crude in the holes can stick to the sealant and foul up the threads.

Joe

OK I think I get it now. The bolts actually screw into the water passages. I was thinking they were maybe just exposed to the area of teh head and block head gasket area and the gasket may be leaking water into the bolt area. Which I suppose it might be but then I may need a new head gasket as those water holes are small and the gaskets have holes for the bolts so they should be sealed. But I could see how the water could work it;s way up the bolt threads fromt he wsater passage below and weep out on the top under the bolt head and into the area under the valve covers.

I did some searches using google and found a lot of cases of this.

I will try sealing it with one of the compounds mentioned.
Right Stuff, Permetex Aviation Sealant, Super 300, Permatex High Temp Thread Sealer with Teflon, permatex gold or copper, or joint compound.

I am leaning toward the "Permatex® High Temperature Thread Sealant with PTFE (Teflon)"

OEM specified. Locks and seals threaded fittings. Resists leakage, vibration loosening, moisture, hydraulic fluids and diesel fuels. Lubricates threads for easy assembly and disassembly. Won’t shred or wear like thread seal tape. Parts may be repositioned up to 4 hours after application. Temperature range from -65°F to 400°F (-54°C to 204°C). Contains PTFE.

Suggested Applications: Head bolts into through holes, oil PSI sending units and sensors, oil and coolant lines, fuel fittings, rear axle fill plug, brake and power steering fittings.


Sounds like it is made for this application (Head Bolts).


Any known reason not to use this stuff?

It's good stuff, but unless you're a professional plumber, a 16-ounce jug of it will still be around when your grandkids are working on the stovebolt truck they inherited from you. A little goes a long way. Super 300 is much more versatile, and it's available in a 4-ounce container. PTFE (Teflon) didn't exist when Super 300 was invented, so old fogies like me stick with what we have been using for 40-something years. Either one will work great for your purposes.
Jerry

which of the head bolts actually enter the water jacket?

Is it all the 9 long ones (on each side under the valve cover) or even the short 8 bolts on the side of the head by the exhaust manifold as well that go into the water jacket? Kind of looks like all of them. Although I guess it those short ones weeped it just goes on the outside of the engine and would not get into the oil.

Trying to figure out if I have to pull all 34 or just 18 or some smaller subset of bolts. One by one cleaning and sealing will take some time.

I guess I could try to reseal a few of them and see if it fixes the leak and try again if not. Or just do them all but then I may make ones that are not leaking leak from pulling them out and putting back in.

I guess I could put it together and then put water in and presserize the system somehow and try to see what bolts weep. That might be hard to do or see.

Also if I do not remove the head there does not seem to be a way to clean the threads down on the block as they would be pretty deep (below the head) so am I going to be able to seal the threads?

I have read that others have done it by just pulling one at a time and cleaning and sealing but it seems like not being able to clean the threads in the block would be an issue.

Or is there some other way to do that without pullig the heads off?

If I remember right on the sbc all the head bolts enter the water jacket. Others will correct me if I'm wrong.

I doubt if it will be necessary to clean the threads in the block. When we're prepping a race engine block, I use a slightly worn threading tap with the points of the threads blunted slightly to keep from oversizing the threads in a reversible drill motor to chase the block threads. The maximum cooling system pressure you're going to encounter will be 15 PSI or so, and just about any brush-on sealer will handle that without a detail cleaning of the threads. Unless you're seeing coolant drip lines on the outside of the block, just pull and seal the bolts under the valve covers one at a time. I guess it would be possible to fabricate a thread chaser by welding an extension onto a worn-out 7/16X14 tap, but I don't think it's really necessary.
Jerry

OK thanks again. Now to find the time to do it!

Ok well I was thinking I could pull each of these head bolts in the valve cover area (18 total, 9 each side) and clean and reseal them but looking at it I would have to remove the rocker arms to get the top center head bolts out.

I am not sure how to properly adjust them when you reinstall them so I am thinking maybe I should bail and let a "proffessional" do it.

Also the couple of head bolts that do not interfer with the rockers (on the ends) seem to be pretty tight. Should be around 80 pounds but I am afraid I may snap the bolts. They have been in there 25 years.

Probably should use an impact wrench to break them loose?


Any guidance anyone? Is this a "no brainer" or should I let someone with smarts on engine internals do it?

I suppose I could just reseal the ones that do not require the rocker removal. That may get most of the weeping down to a minimum.

What is the best way to break these loose without braking a bolt?

Any thoughts on how to break the head bolts loose?
Just use a big lever socket wrench or do you need an inpact wrench?
What about adjusting rockers and valves after having to remove rockers to remove the head bolts? How do you do that?
Should i take it somewhere to do this professionally?

Just use a good 6-point socket, an extension, and a LONG breaker bar. I've got a 24" Snap-On swivel-head breaker bar stashed away for the really tight bolts, and I'm not afraid to lean on it vigorously. Be sure you've got a good-quality socket that fits the bolt head snugly.
Jerry

THANK YOU HOTROD LINCOLN!!!!

I took come time this afternoon and went through all 18 Head bolts under the valve covers and 3 of them were not tight. Maybe 15-20 lbs! And those had a lot of sludge and oil and water on the shaft.

Those and all the others were pretty clean on the threads. They were oily or watery but there did not appear to be any sealant on the threads? I wiped them off and sprayed with brake cleaner and wiped again and wire brushed them but they did not need wire brushing as the threads were clean except a few that had one thread of a little corosion on the bottom.

I did find some evidence of a little RTV or the like, part way down the shaft hole on a couple but nothing on the threads.

I also tried to clean out the holes and the threads in the head the best I could. mostly just oil and sludge type of stuff.

I cleaned off the top that the head of the bolts rest against and then applied sealant on threads and under the head and tighten them to the corect torque setting.

I did one at a time and then when done with a side I went inside out rechecking them. Then 2 hours after I rechecked them again. Sealant says you can adjust up to 4 hours and to let it set 24 before adding fluids or b=putting into service, ideally up to 100 hours for full maximum set.



Another thing I found while cleaning up around the holes was that on the bottom rim where the valve cover sets there was a thumbnail sized piece of cast iron that had chipped off one of the edges of the bolt holes for the heads. Glad I fould that. Don't need it floating around in there!



I plan to flush the oil a couple times to get any antifreeze residue out of the oil.

The other day I took a quart or so out of the oil pan and it looked normal in the clear container I put it in. Just looked like oil. But when I drained it out into another container there where some very little droplets of antifreeze in the bottom sticking to the plastic of the container I originally drained it into.

So there is some antifreeze in my oil in the oil pan.

I plan to try to flush it with some new oil then refill and after getting up to temp drain it again and another new oil filter. Then maybe take a quart out every once in a while to inspect it and also under the valve covers to check for signs of leaking/weeping.

If I still see some I may try a flush product on it.

How does that sound????


Thanks again for your help!!

"I love it when a plan comes together". It looks like you're well on the way to getting the problem solved. If the oil hasn't turned milky-looking, you probably don't have enough contamination to worry about. I'd suggest doing an oil and filter change at around 1,000-mile intervals a couple of times to be sure as much of the coolant has been flushed out as possible. Good show!
Jerry

I will do it more often then that as I usually only do about 500 a year in it.

The oil looked fine. no milkshake stuff. looked like normal oil other than the residue, almost microscopic droplets, at the very bottom.

THanks again!

By the way, I need to install my intake manifold. This is a 1970 350 v8 in it I have read that most people say PRV the water intakes on both sides of the gaskets. and a dap on the end seals on both ends but not on or under the actual rubber end seals other than the extreem ends. OR scrap the end seals and just PRV them. These end seals have the tabs and the spikes that go down into the block so I think they are OK to use as long as you do not PRV them all over.

Does that sound about right?

The directions with the gasket just says a couple daps of high tack not on the water ports but between the water and the fuel runner ports just to hold it in place and high tack the end seals in on the spikes and ends and then they say a dab of PRV on the end seal ends where they go under the port gasket. So no PRV around the water ports?


Last time I did this the end seals squished out on the front passenger side from too much PRV. I ran a bead on the top and bottom of that rubber seal. Ooops. But I also put PRV on the water ports and they seemed to seal well.


What do you recomend?

I personally never had much luck with the rubber end seals, although you are right the ones with the little alignment pins seem to stay a little better. Someone had mentioned Permatex "the right stuff" earlier, I've had a lot of luck tossing the rubber seals (as GM did years ago) and using a bead of that. I normally just put a real thin wiping of RTV around the water ports, helps hold them too while you are positioning the intake. my 2cents

I use the 3M yellow trim cement ("Gorilla Snot" if you happen to be a NASCAR wrench). Put a thin layer on the block and the underside of the end gaskets, let it dry fully, and it sticks to itself when the gasket is applied to the block. Use a little dab of RTV sealer where the end gaskets and the side pieces come together, and some Super 300 around the water ports, front and rear. DO NOT use any sealer around the intake ports. I've seen my competitors on the race track use a straight bead of RTV instead of end gaskets, but I'm not fond of that practice.

Manifolds that have been milled to match up with milled cylinder heads can have some pretty serious gasket fit problems, and troubles with vacuum leaks, so a lot of special attention needs to be given to anything that's not factory stock in the block/head/manifold machining area. I used to angle-mill cylinder heads for better race performance, and the intake had to be matched to a specific set of heads and used as a set. This was done on 350 engines that produced upwards of 600 HP at 7,000+ RPM, not anything that got run on the street!
Jerry

Something to consider is having an oil analysis done. I have Mercedes Benz engines in my work trucks and had an issue with a egr cooler going bad and needed to know if the engine had ingested antifreeze. The oil looked good to the eye, no antifreeze came out when the drain plug was taken out. The results confirmed that the oil did have antifreeze in it. The glycol was burned off and that is why the oil wasn't milky or show antifreeze in it. I learned that antifreeze has (sodium? don't have test in front of me.)in it. This is the byproduct left after the glycol cooked itself out. The antifreeze manufacturers add this to aid in showing the presence of coolant in engine oil. The cost of an oil analysis is 16.00 at a local lab here in Minneapolis MN. If interested do a search about oil analysis. Its interesting what you can learn about your engine.
Don