4.1 making bubbles

[shmed]

hi all the 4.1 I put in the t is now blowing bubbles in the overflowtank. oknothing in the oil an no smoke out the tails,
ive pulled the heads which were studded (an they didn't seem as tight as I expected used a 3/8 drive racket on most of them)
ok upon a visual inspection I didn't see any damage to the gaskets or head surfaces
This just (the bubbles) started the other morning when we went to warm it up the car hasn't seen more then 15 psi an the motor might have 1-200 miles on it.

any thoughts
thanks

 

[dynoman]

Start with a new radiator cap, it shouldn't push coolant or air past it until it's over temp & 16# ( which has nothing to do with boost) assuming the block isn't cracked or loose heads. Was the car up to temp or still cold ?

 

[Steve V]

Did you check the block for cracks?

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[GBGN1]

Yeah Id 2nd the crack idea

 

[forzfed]

So, what did you find out?

 

[D's GN]

hi all the 4.1 I put in the t is now blowing bubbles in the overflowtank. oknothing in the oil an no smoke out the tails,
ive pulled the heads which were studded (an they didn't seem as tight as I expected used a 3/8 drive racket on most of them)
ok upon a visual inspection I didn't see any damage to the gaskets or head surfaces
This just (the bubbles) started the other morning when we went to warm it up the car hasn't seen more then 15 psi an the motor might have 1-200 miles on it.

any thoughts
thanks

I recall a thread awhile back about ARP studs used on iron heads, a few of the studs were too long at the shoulder not allowing enough thread engagement from the nut. The torque wrench may be indicating correct torque but it is pulling down on the unthreaded shoulder vs the cylinder head. The quick fix is to add another washer for the extra thread engagement. Might be something to look for when you reassemble the top end.

D

 

[shmed]

hi all thanks for the tips
so far heads are off flat an crack free
the block is flat an crack free
the machinst thinks it was a combination of overboost an detonation ??

D'd thanks for the tip i do remember seeing at least 2 studs on either side that were longer then the rest like 1/4 or so.

 

[ek02]

What head gaskets were you using?

 

[RmvBfrFlght]

shmed, the part that bothers me the most is that you mentioned that the head stud nuts didn't appear to be all that tight. Having removed them easily with a 3/8" drive ratchet. They should have been torqued to 80 ft/lbs (or close to that, I don't know the exact spec). Odds are that the heads weren't clamped down tight enough and the head gaskets started to leak.

So other then the too long end studs, either someone didn't do the final torque on the studs, or they needed to get retorqued after a few heat cycles.

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