overheating problem

[one finger john]

The areas that Mike has indicated are part of the cylinder block deck. I would be leery if there is oil seeping from those areas. They are sealed by the head gasket and normally shouldn't need extra sealer.
When you replaced the cylinder heads did you use a quality straight edge to check the decks flatness?
What year is the block and is the manifold American or Chinese made? Single plane or dual plane?
When you lay the manifold into the engine less the gaskets do all the angles line up properly?
I don't think that you have overheated the engine enough to warp the block but what do you and the temp gauges call overheating? 200*, 225*, 250*, even 300*? I wouldn't worry about 200*.

If you haven't changed cam timing or anything else other than heads manifold, and EFI, go back, start at the beginning and call the people that supplied the heads and see what they recommend for head gaskets and follow their advice. Not what you think is less expensive and "will work just as well". Check the cylinder decks for flatness with a quality machinist edge. After that checks out O.K. (if it does) check the manifold for straightness and fit. Might have to return the manifold for another one, esp. if it is Chinese. If the distributer is not controlled by the EFI then set it where ever it starts the best and runs the smoothest. What does Fast say about initial distributer timing? If the distributer is controled by the EFI computer then you probably will have to set the distributer @ no.1 TDC and be very exacting about it. Then don't change it. Let the computer do it's job. The EFI should have a base fuel mixture map in it to get you pretty close to running. There are millions of small block Chevys so this should be no mystery.

Keep plugging and use the process of elimination. Everything will work out, you'll see.

John

 

[Mike]

Wait a min.... Damn.. Your saying I need to remove the heads and put silicone on them 4 spots just below where the manifold sits.

No, I'm not saying you need to remove anything at all. What I am saying is that is an area that I have seen as the location of oil leaks. That became a point we would pay particular attention to, on the round track stuff, just to be certain it would not jump up and bite us.

 

[oino]

If I use a spray bottle with soapy water in it. Spray it around the problems areas should I get bubbles?

I'm getting all new gaskets and everything I need. Going to lock my self in the garage tonight and fix this thing.

 

[old round fart]

Hoop a shop vac up to the carb and put silicone in the suspected leak area and when it sucks it in, turn off the vac and let it set up.

 

[oino]

Hoop a shop vac up to the carb and put silicone in the suspected leak area and when it sucks it in, turn off the vac and let it set up.

there's no way that could work

:-D

 

[Screaming Metal]

If I use a spray bottle with soapy water in it. Spray it around the problems areas should I get bubbles?
Only if its pressurized....
I'm getting all new gaskets and everything I need. Going to lock my self in the garage tonight and fix this thing.

On the chinese intakes, while the overall appearence looks good, its a good thing to check them out good before bolting them on. By that, I mean, stick some gaskets on the intake surface, lay the intake on there and make sure you got some clearence at the ends of the intake so you'll have a seal when you silicone it and pull her down.
I've seen some of those intakes hit middle first and stand up off the intake faces, and then theres been a couple that had porosity in the alum., meaning it was sucking air thru the casting.
It had sand in the casting, had to grind it out and TIG it up....

 

[old round fart]

there's no way that could work

Yes, but every thing else you tried was a complete success! Good luck!

 

[oino]

I got the intake manifold off. Discovered that the gaskets were not sealed in the corners again and the whole gasket was covered in oil. Only place safe was where I put silicone around the water ports.
Seems oil was getting into the intake valves.
Cheap ass speedway gaskets.
Went ahead and did a compression check. All good on that.

 

[2old2fast]

O.K. , now that we've been on this for 6 pages , I'm gonna be capt. obvious here ... in your 1st post you said these were "new" heads etc. that you got off the "net" , .... were they really NEW ???? From what I've been reading elsewhere these heads are very prone to cracking , I hope you have a good set ???
dave

 

[oino]

O.K. , now that we've been on this for 6 pages , I'm gonna be capt. obvious here ... in your 1st post you said these were "new" heads etc. that you got off the "net" , .... were they really NEW ???? From what I've been reading elsewhere these heads are very prone to cracking , I hope you have a good set ???
dave

I hope I do too.

 

[oino]

Thank you again for every ones help. I really appreciate it.

 

[Screaming Metal]

I hope I do too.

Did these heads come in heavy cardboard boxes and wrapped in plastic? Did they look new? The Deck ought to be Bright, a fresh machined surface. Next time, look into the ports at the valvestems and in the exhaust ports, look for carbon and do you see any rust where the valvestem opens up to the valves head? Look at the base of the valvespring/ shim area....is it clean in there? There are tell-tell ways to check.

 

[409T]

From what I've been reading elsewhere these heads are very prone to cracking , I hope you have a good set ???

Back in post #15 you (onio) said that the top hose was getting hot and hard. Many times that indicates a leak into the cooling system from a bad head gasket or a crack in either the block or head(s).

 

[Keeper]

I got the intake manifold off. Discovered that the gaskets were not sealed in the corners again and the whole gasket was covered in oil. Only place safe was where I put silicone around the water ports.
Seems oil was getting into the intake valves.
Cheap ass speedway gaskets.
Went ahead and did a compression check. All good on that.

Ahhhhhh question for you. Are the gaskets the hard blue ones? Or the softer composite type?

If they are the hard blue ones, and you are using a aluminum intake, they will never seal correctly. I learned that the hard way.

Let me track down the post, it has the solution in it.

 

[Keeper]

Here you go. I followed Mike's advice to the letter, and its been a year without any more issues. I just hate to think of what I will have to go through to get them back off...lol

http://www.tbucketeers.com/threads/engine-builder-question-intake-gasket-not-sealing.13828/

 

[Screaming Metal]

Yep, When you clean things with laquer thinner or paint thinner, with a rag, and scrub that surface, get it good and clean, that way that gasket sealer will BOND to the metal.
Its my habit, scrap, wipe, thinner on rag, wipe again, dry, then wipe again with thinner on a new rag, dry, then my finger should drag on that metal surface, instead of slide. Then, that sealer will bond....

 

[oino]

Back in post #15 you (onio) said that the top hose was getting hot and hard. Many times that indicates a leak into the cooling system from a bad head gasket or a crack in either the block or head(s).

No coolant in the oil.

Did these heads come in heavy cardboard boxes and wrapped in plastic? Did they look new? The Deck ought to be Bright, a fresh machined surface. Next time, look into the ports at the valvestems and in the exhaust ports, look for carbon and do you see any rust where the valvestem opens up to the valves head? Look at the base of the valvespring/ shim area....is it clean in there? There are tell-tell ways to check.

Ya the heads came in a box with formed foam wrapped in plastic.
The surface was nice and clean. Before I installed them I wiped them down with thinner.

Ahhhhhh question for you. Are the gaskets the hard blue ones? Or the softer composite type?

If they are the hard blue ones, and you are using a aluminum intake, they will never seal correctly. I learned that the hard way.

Let me track down the post, it has the solution in it.

I've tried 3 different intake gaskets.
First ones were fel-pro 1255 vortec gaskets, Second ones were SuperSeal vortec gaskets(Standard size) bought the at speedway. Thrid ones were Fel-pro MS90131. Thats whats on there now. I made sure I put plenty in the corners.

Overheating problem solved with bypass.
But oil leak is still there all 4 sides of the motor at the bottom of the head.
And not it is missing and popping and backfiring out the exhaust.
When it backfires a puff of black smoke comes with it.

I tryed replacing the plugs already.

If one of the head gaskets were messed up, or a crack in the head, or a valve not sitting right wouldn't that show on a compression test?

If the manifold isn't sealing right on one of the intake ports could that allow oil to get past the valve and into the cylinder and cause some of the problems I'm having?

 

[Screaming Metal]

If one of the head gaskets were messed up, or a crack in the head, or a valve not sitting right wouldn't that show on a compression test?
Sometimes there has to be a running load for it to open up. Usually a compression check will show it. Sometimes you have to do a Pressurized Cooling System Check....

If the manifold isn't sealing right on one of the intake ports could that allow oil to get past the valve and into the cylinder and cause some of the problems I'm having?
Sometimes, usually you'll be sucking oil from the lifter valley, or have a vacuum leak, or both. If the manifold isn't sitting pretty as Mike said....it'll leak for sure.
In your case Chris, what I would do, is add some oil dye to your oil, then break out the blacklight (they sale them cheap now)....you'll find your leak....
Like I said, sometimes you gotta look inside the intake runner with a borescope. They have them at the stores for the good customers, a rental shop, or pick up your own from Harbor Freight for $69. Screen is kinda small, 2.5", but it works. If its leaking, you'll see oil inside the runner at the parting line, inside the intake port will also have a oily residue in it.

OK, the overheating issue is solved, by the bypass. Is this back-firing your speaking of happens as its idling? When it revs? Both? We need more information. How is the vacuum gauge reading? You could be running rich and have a pop when you snap the throttle closed....having raw fuel inside the headers.
Is the motor reving still causing spitting and popping? If so, timing may be the cause, or maybe your EFI needs adjustments....
Sometimes tight valve clearences will cause missing or a pop....valves are not fully seated, or sticking slightly.

 

[oino]

The back fire and popping happens at idle. It stops popping and just back fires if I rev it.

I was wonder if oil is getting past the intake gasket and into the inake port making the valve not seat and causing the miss, popping and backfiring.

None of this fixes my oil leak. I think thats the heads.

You know I havn't pulled the valve covers sence I put them on. I'm going to do that right now.

 

[Screaming Metal]

It could, but highly unlikely. Unless somethings not flat or even. It almost sounds like from the symptoms, spark scatter, like the distributor endplay is way too much (distributor shaft riding up and down as the distr. gear meshes with the cam gear), valves sticking, maybe too tight.
Sounds like either a valve is open when the plug fires or the timing is out....sorry, just thinking out loud....