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Losing Coolant through Head Bolt ?

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CAJUN C4

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87' Engine

It started about 6 mos ago losing about 2 quarts of coolant a week.Put it on the rack and the very last head bolts on both sides show signs of leaking coolant. Maybe I didn't put enough sealer on the threads? I believe these bolts go directly into the water jacket.You think I can fix this problem by taking the bolts out and add sealant to the threads or is it possible it's a head gasket issue.It doesn't leak enough to show visibal signs on the ground. It must evaporate being right at the exhaust manifolds.
Anyone have or hear of this problem? It did however,not leak a drop for three years after the re-build.

Perplexed
 

bossvette

Gone but not forgotten
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West Unity Ohio
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1968 1997
87' Engine

You think I can fix this problem by taking the bolts out and add sealant to the threads

Perplexed

It can't hurt to try, Do you have washers on the head bolts and were they torqued correctly?
 
C

CAJUN C4

Guest
I dodn't think they had washers on any of them.I did torque them to spec.
 

gmjunkie

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Old Fort NC/Vero Beach FL
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I dodn't think they had washers on any of them.I did torque them to spec.
Re-torque All Head Bolts to factory spec's and add 5 lb it will probly stop!!:upthumbs
 
C

CAJUN C4

Guest
Re-torque to factory spec's and add 5 lb it will probly stop!!:upthumbs
I'll try it..the problem is that you have to take off the exhaust manifolds to get to the bolts....might as well add sealer while I went that far.
 

JimVette

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gulf Breeze Fl
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If you were loosing that much through the bolts I would question the condition of the head gaskets.
 

gmjunkie

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I'll try it..the problem is that you have to take off the exhaust manifolds to get to the bolts....might as well add sealer while I went that far.
Thats True!! Don't take them all out at once!!Only do the bottom row!! And just at the top 3/4 of a inch and head!!Sealer on the threads might throw your Torque off!!:upthumbs
 

gmjunkie

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If you were loosing that much through the bolts I would question the condition of the head gaskets.
I seen SB Chevy's do this after some Time or a Head job!! I usually re-torque and 99 times out of 100, Problem Solved!!84-99 seam to be the worst for it!!:upthumbs
 
C

CAJUN C4

Guest
Thanx guys...looks like I'm on the right track.
 
G

grapeknutz

Guest
Since those head bolts DO go thru to the coolent jacket the require sealent on the threads.
 

Galen

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The recomended thread sealant is teflon paste. Loctite makes it. Also moly lube under the head, if it has aluminum heads washers are required. Use the correct torque do not add to it it will only stress the fastener and the threads in the block. The teflon will seal the threads even if it is wet.
 

Rowdy1

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Have You...........

Pulled a valve cover in a while? Seen any coolant in the oil, dipstick? Why would only the exterior bolts leak and not all of them? Not trying to jinx you in any way but I think if it were me, I'd seal all of them.
 
C

CAJUN C4

Guest
Pulled a valve cover in a while? Seen any coolant in the oil, dipstick? Why would only the exterior bolts leak and not all of them? Not trying to jinx you in any way but I think if it were me, I'd seal all of them.

It seems that only the last ones on each side are leaking. I must have not sealed them properly.No water in the Oil.No water in the exhaust either.Might give that TFE sealer a try.
 

Galen

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1990 White/Black Interior 6sp Coupe
I have seen many times just the outside bolts or bolt leaking. Has nothing to do with the head gasket. It was most likely even torqued correctly. I have seen people not use sealer on the outside bolts thinking it wasnt important. It sounds like you put the heads on yourself if so you know if you used a sealer. If you have doubt re do all of the bolts. Start in the middle and do one at a time using the tfe and moly on the bolt under its head. Do not try to use oil the torque will not be correct. If the bolt is dirty wire brush it. Normally I would run a tap in the block threads but more people dont than do so in your case you cant so just use the sealer on the bolt. Wipe it onto the threads with your finger to insure a good seal. Also check for cracked or broken washers. I am not sure why but several of the leaks I have found had cracked washers. At this point the bigest cost is your time so it is worth doing. Good Luck.
 
C

CAJUN C4

Guest
I have seen many times just the outside bolts or bolt leaking. Has nothing to do with the head gasket. It was most likely even torqued correctly. I have seen people not use sealer on the outside bolts thinking it wasnt important. It sounds like you put the heads on yourself if so you know if you used a sealer. If you have doubt re do all of the bolts. Start in the middle and do one at a time using the tfe and moly on the bolt under its head. Do not try to use oil the torque will not be correct. If the bolt is dirty wire brush it. Normally I would run a tap in the block threads but more people dont than do so in your case you cant so just use the sealer on the bolt. Wipe it onto the threads with your finger to insure a good seal. Also check for cracked or broken washers. I am not sure why but several of the leaks I have found had cracked washers. At this point the bigest cost is your time so it is worth doing. Good Luck.

Thanx Galen I'll do it.
 
C

CAJUN C4

Guest
Washers?

My head bolts have the large flange type head and are 87's and didn't have washers on them.
 
C

CAJUN C4

Guest
I seen SB Chevy's do this after some Time or a Head job!! I usually re-torque and 99 times out of 100, Problem Solved!!84-99 seam to be the worst for it!!:upthumbs
I just Love it when you guys are right. Pulled off the Ex. Manifolds Saturday & sure enough the back bolts had backed out a 1/4-1/2 turn.we re-torked to 60 ft lbs and I think all's well...no more bubbles from radiator.
Thanx again guys for your input.
 

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