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02 Crankcase pressure leak

Posted: Mon Apr 08, 2019 10:46 am
by michael_perrett
A rebuilt 02 engine has a crankcase test leak around one head bolts under the washer. The one nearest the dipstick. Was there any discussion in the past about one head bolt seated in a open threaded hole (not a blind hole), one that was connected to the crankcase?

Mike Perrett

Re: 02 Crankcase pressure leak

Posted: Mon Apr 08, 2019 12:07 pm
by givergas
"I do recommend using either standard grade thread locking compound or a sealant on the threads going into the cases. I've had to fix leaks which were through the stud threads in the past.

Ed[/quote]" from the man himself from when i was rebuilding my engine.....albert

Re: 02 Crankcase pressure leak

Posted: Mon Apr 08, 2019 12:25 pm
by Bullfrog
;) What that guy Ed was quoted as writing . . .

. . . aaannnd . . . check to be sure that all the head nuts are threaded deeply enough. I've experienced one which was not threaded deeply enough. This allowed things to come to full torque before the head nut came down tight on the head - the results were not good (and the nasty symptoms happened multiple times. Let's not go into how many times, OK?) After finding and tapping out the offending head nut, the problem went away. ( . . . and yes, IF I had done a pressure test on the engine earlier, I would have found the problem MUCH more quickly. :? )

Ed
PS: I can't put my hands on a set of open cases right now, but my memory suggests that it is the threading operation which "breaches" the side/bottom of the stud hole in the cases allow a "connection/leak" by way of the stud threads. But my memory can't come up with a definitive answer on whether the situation applies to only one, or more, of the stud holes.

Re: 02 Crankcase pressure leak

Posted: Mon Apr 08, 2019 12:38 pm
by givergas
yea thats what he said

Re: 02 Crankcase pressure leak

Posted: Mon Apr 08, 2019 2:08 pm
by michael_perrett
I checked the relation between the head nut and the stud while assembling the engine. I used two washers instead of one on each nut to allow enough "safety" clearance. That is not the problem here. I need to know if this stud is in a blind hole or not.

Mike Perrett

Re: 02 Crankcase pressure leak

Posted: Mon Apr 08, 2019 2:45 pm
by thrownchain
I can't tell you about the stud, but make sure you don't have a leak past the head gasket, if the head is warped it'll leak.

Re: 02 Crankcase pressure leak

Posted: Tue Apr 09, 2019 4:54 am
by Larry S
I don't know about a 02, but on a 95 the stud near the dipstick is not in a blind hole.

With the cases split you can see the base of the stud.

Larry S

Re: 02 Crankcase pressure leak

Posted: Tue Apr 09, 2019 5:59 am
by michael_perrett
Thanks Larry, I will end up pulling the top end as I suspected.

Mike Perrett