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#86326 07/13/15 06:12 PM
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Gentlemen,
I have a 250 Chevy, RV Cam, Langdon Headers, Offenhauser 4 bbl intake, bored .030" over. About 6000 miles on the engine.
Runs great, however, I started it last week and white smoke was billowing out of the tail pipe. It cleared after a while, but my coolant reservoir was drained. The smoke is not oil smoke but rather coolant. I refill the reservoir and it burns off to refill repeatedly.
From your experience am I looking at a blown head gasket, cracked head, or cracked block? Are there any tests I can do to determine what's going on?

As always, your help is greatly appreciated.
Thank you.
Ken

Last edited by El Viejo; 07/13/15 08:00 PM.
El Viejo #86328 07/13/15 08:46 PM
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I'm hoping for you that it's a head gasket. Just for fun I would re-torque the head to see if that makes any difference. Pull plugs and see if there is evidence of water. Is it still running go all cylinders? Pretty safe bet it didn't freeze and crack in Oakland. You probably won't know for sure without pulling the head.


"I wonder if God created man because he was disappointed in the monkey?" Mark Twain
El Viejo #86330 07/13/15 09:16 PM
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You can pull the plugs and do a Rad. Pressure test. This may???? tell you which cyl. Mite?? be bad.( issues head gasket, Block crack, head crack OR a valve seat that may have been cut to deep.)If you find No cracks Have the head pressure tested.


Larry/Twisted6
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El Viejo #86335 07/13/15 11:19 PM
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Just as a precaution, check your oil to confirm water is not getting into the crankcase. If the oil is milky, you have water.

El Viejo #86336 07/13/15 11:32 PM
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Years ago I had a leaky head gasket. It steam cleaned one cylinder, so checking plug was obvious. If only I'd checked the head bolts, I'd have found a loose one but replaced the gasket. Speculated when it was rebuilt a few months before some oil got in the hole. It would torque to the oil but later loosen up. You should have seen the huge white plume when I took off from traffic light, didn't have money then to make pay for a tow.

Beater of the pack has wise advice.

Mark


Mark
'67 Camaro L6-250
El Viejo #86337 07/14/15 12:36 AM
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Yep, like everyone has said...check your head bolts...did you tighten them down in the proper sequence? You can do a compression test to see if you have a blown head gasket.


1966 C10 292/tko600 http://67-72chevytrucks.com/vboard/showthread.php?t=596643
1964 C20 292/sm420
El Viejo #86341 07/14/15 03:57 PM
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Gentlemen,
Thank you all for the advice. I'm on it.
Regards,
Ken

El Viejo #86347 07/14/15 06:12 PM
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Gentlemen,
Update:
Retorqued the head bolts. Only one moved and only a little. Definitely water in the oil.
Will pull the head and hope it's the gasket.

Thanks again.

Ken

El Viejo #86348 07/14/15 06:29 PM
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Do a compression check before you pull the head. You may be able to isolate the trouble. Usually if its a head gasket, two adjoining cylinders come up low as compared to the others. Might give you a head start in diagnosing the issue.

El Viejo #86351 07/14/15 08:50 PM
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You said this was a 250. Well I may have a bit of bad news The head bolt over the water pump area ARE Prone to crack to the inside of the block Some times to the out side. And will not OR may not show up with a compression check. BUT I would a compression check first anyway.


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El Viejo #86358 07/15/15 06:30 PM
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Gentlemen,
Pulled the plugs. Water on plugs 3 and 4. No water on any others and all six were "coffee brown". Cranked 'er over and water flew out of #3. Number 4 just a tad of water. # 1 near the water pump area was dry. Still runs well, but lots of steam!!
Next step is pull the head.
By the way, is there a way to tell if it's just a head gasket, or if there is a crack in the head or block, before pulling the head?
Thank you.
Ken

Last edited by El Viejo; 07/15/15 06:31 PM.
El Viejo #86360 07/15/15 09:43 PM
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Not really.


Larry/Twisted6
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El Viejo #86362 07/15/15 11:18 PM
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Pull the intake first.
It could be that only 1 cylinder has a problem but the water went to the other cylinder via the intake. Not likely but could be, so I'd check that before water gets everywhere.

I would also do a compression check before you pull the head, why not? You could still pull the intake first.

Cracks can be really hard to find, I once cracked a cylinder wall, had to run my fingernail up n down the cylinder til it snagged in 1 spot. Still couldn't see it but could feel it.

Turns out the wall was less than .040" thick right there, Ford Cleveland.

So far, looks like yours might be a head gasket, hope so.

El Viejo #86395 07/17/15 06:27 PM
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Gentlemen,
I pulled the head and there is no obvious head gasket issue. No burn on the gasket between cylinders. Could the head have warped and allowed coolant to flow into the cylinder without obvious track on the gasket or head?

Thanks.

Ken

El Viejo #86397 07/17/15 06:33 PM
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YOU BETTER SEND THE HEAD TO MACHINE SHOP FOR CRACK TESTING, ITS COMMON FOR THEM TO BE CRACKED. ALSO IF YOU RUN IT AND THE PROBLEM CYLINDER FILLS WITH ANTIFREEZE/WATER IT WILL HYDRAULIC THE CYLINDER AND BLOW THE ENGINE. PLUS ANTIFREEZE IN THE OIL WILL KILL ROD AND MAIN BEARINGS ALMOST INSTANTLY UPON CONTACT.......


I BELIEVE IN " JOHN 3:16 "
El Viejo #86398 07/17/15 07:31 PM
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Was the intake wet in ports 3&4, ie were they "talking" to each other?

Did you check the cylinder walls for cracks? Remember they can be VERY hard to find.

When my wall cracked (billowing white smoke out 1 side of a v8), I drove the rig almost 100 miles to a friends garage, tore it down & found the wall crack. Later on teardown, pistons & bearings looked so good I could have re-used them. I babied it, but ended up with about 12 quarts of oil+antifreeze in the crankcase - surprised things looked as good as they did. So you probably haven't done any damage down below, yet - but gotta find that leak!

El Viejo #86403 07/18/15 10:46 AM
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It only takes a hair line crack for water to seep through. Have the head and block magnafluxed and checked for cracks.


1966 C10 292/tko600 http://67-72chevytrucks.com/vboard/showthread.php?t=596643
1964 C20 292/sm420
El Viejo #87044 09/11/15 05:34 PM
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Took the head to the machine shop and had it magnafluxed and checked for warpage. No warp, no cracks based on the mag. testing. Reinstalled. Still burning coolant #3 cylinder. Machinist said there could be a "pin hole" and not revealed by mag. testing.Hate to pull the engine but can. Any ideas before I do? Thank you.


Ken

Last edited by El Viejo; 09/11/15 05:35 PM.
El Viejo #87045 09/11/15 05:38 PM
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Does the head have lumps installed in the intake ports?


Inliner Member 1716
65 Chevelle Wagon and 41 Hudson Pickup
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Mr. T Lowe,
No the head does not have lump ports.

Ken

El Viejo #87047 09/11/15 09:19 PM
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If you had the seats replaced It Could vary well be leaking right there. DID you Have The Head Pressure Tested??


Larry/Twisted6
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El Viejo #87079 09/14/15 07:42 PM
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I did not have the head pressure tested. When I was disassembling the head to take to the machinist for magaflux and flatness check, I noticed two freeze plugs in the head the were "rotted" through. The machine shop and I both agreed it was electrolysis. I've since corrected the coolant by raising the pH. But is it likely that the electrolysis could have also gotten through the cylinder wall?
Thanks.
Ken


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