View Full Version : newbie has question- LT-1 block leaking
i am new to this board but i have been reading it for a while and cant seem to find the answer to my question. i have a 97 prostar 205 with the LT-1(i love it by the way). i put it in the water for the first time this year and was checking the motor for leaks. i found a water leak coming from the block right near the petcock for draining.
this is going to be hard to explain without pics but i will try.
on one side of the block i have a petcock to drain it. just above that and towards the front of the engine is where the casting of the block sticks out a little, maybe a half inch. it is kind of triangle shaped and is protruding out from the rest of the block. on the bottom of this area, water is coming out in a steady stream.
the engine is not running hot and the pump is keeping up with it just fine. i cannot see under this area to see what is going on so i am wondering if this is some type of pressure release or some type of drain? i winterized it real well, drained the petcock, removed sensor, drained manifolds, etc.
is there anyone familiar with this? any info would be great!
thanks
Leroy
06-09-2005, 10:39 AM
Muck; First, welcome aboard! Sorry your first post has that title.
Is it really just casting in that area or is there a plug or insert of any type where the leak is? Probably really small, but can you see the crack?
This is on the other side from the knock sensor right?
no i cant see a crack. the water is coming from underneath this casting area. without a mirror, i cant see what is under there. it feals rough on the underside of it, like there could be a plug or something in there.
i was trying to find some other pics on this board that maybe i could use to show the general area. i will keep looking.
thanks for the reply!
zberger
06-09-2005, 11:02 AM
sounds like a freeze plug could have worked its way loose.. that could be fun to change out.
here is a pic(hopefully) look between the freeze plugs, and near the drain hole. you will see the area i am talking about that sticks out a little.
zberger
06-09-2005, 11:10 AM
are you sure it couldn't be dribbling down from the freezeplug and just dripping off of that edge?
cause from what i can see, if that part that sticks out is broken, your block is cracked man.
counting from left to right- look just below the 5th oil pan bolt. that is where it is coming from.
while at the lake, i sat and looked at it and wiped it for 30 minutes, crossing my fingers, hoping it was coming from the drain or a freeze plug. no luck, it is definatly coming from that area.
i drained the block right there at the petcock. water did come out so it wasnt plugged.
so i would assume the block is scrap if its cracked? prob. not a good idea to use a stop leak?
east tx skier
06-09-2005, 11:19 AM
Muck, sorry to hear of your troubles. Very cool looking engine though. Not to hijack this thread too much, but I see you're from Deadwood, SD. My dad was born in Deadwood. I've got a somewhat notorious lineage in SD as my great aunt was a lady who later went by Dora Dufrane. Ever hear of her?
Hope you get it worked out with your leak.
yes i have heard of her. that name is well known around here.
east tx skier
06-09-2005, 11:58 AM
Never knew her obviously. I have a niece that turned up that bit of info a while back. Her real name was Annie Bolshaw.
BrianM
06-09-2005, 12:01 PM
If it is in fact a small crack and that is were it is coming from I might dry it up real good and try a little JB Weld. That water should not be under to much pressure and the JB might just hold. If that didn't work I would go to a really good welder and have him give it a shot before a dropped $6k on a new motor.
Sorry about your troubles. I sure hope the thing isn't scrap.
rick s.
06-09-2005, 12:37 PM
Missing knock sensor? I had my boat winterized last November and the dealer removed the knock sensor to help drain water out of the block. And didn't replace it. And didn't tell me. When I called them for help (stream of water about the diameter of a large pencil coming out of the block) they suggested looking in the glove box for a baggie that had hose clamps and the knock sensor. Screwed it in, connected it, no leaks, on my way.
The knock sensor location (on my LTR) is on the alternator side of the motor, just above the oil pan / block joint, about in the middle of the motor.
Footin
06-09-2005, 01:34 PM
If it is a small crack, I second the JB Weld idea. That stuff is great, I have used it on many occasions for different kinds of repairs. I always keep some in my tool box.
Diesel
06-09-2005, 02:34 PM
Check your oil right now!
Make sure it does not have any water in it. If it does not you are lucky. If it does you will need a new block. Sounds like all the water was not out of the block and it cracked (hopefully on the outside of the water jacket only). If it only cracked on the outside and you can locate the crack JB weld will work fine and last forever. Make sure you do a proper surface preparation before you use the JB weld.
i checked the oil right away and about every five minutes throughout the day. i want to be sure there is no water in it. it still looks good and is staying right on the full mark.
the knock sensor is still there and is located on the other side.
i was thinking about the JB weld idea, just wasnt sure if i should.
lakes Rick
06-09-2005, 04:54 PM
Deadwood..... Man I would love to live there....
Muck, I know it gets cold up there, and I hope your block didn't freeze last winter...... Take some baby powder, spray it around and up above the leak and see if it doesn't help you trace where it is leaking from..... We do this looking for oil leaks on our older cars.....
My EX's relative was Frank Hamer, the Texas Ranger who put together the famous shoot to kill capture of Bonnie and Clyde.. Sure glad I don't have to hear about it EVERYTIME the history channel has it on anymore..........
yes it does get cold, especially where i store it- at a ski area. it got about -25 last year. it is inside but not heated. i really dont see how it froze cuz i drained it right there at the petcock.
lakes Rick
06-09-2005, 05:07 PM
yes it does get cold, especially where i store it- at a ski area. it got about -25 last year. it is inside but not heated. i really dont see how it froze cuz i drained it right there at the petcock.
Muck, I think the petcock will not drain all the water.. -25, brrrr, cold enough to make any water freeze up pretty hard.. I am lucky as my garage is heated, but...
My old TriStar had to sit in my friends carport one winter.. ( Divorce).. I had winterized it by pumping it full of antifreeze.. We had a real cold snap that year and on the end of my fake hot water shower ( direct line from the block) was a plastic hose sprayer.. It was cracked to pieces from the water in it freezing... No anti freeze was flushed into it... So to make my long story short, any small amount of water left can cause problems.... I was sure glad I had spent some time winterizing my boat well that year...... Rick
gregg
06-10-2005, 09:08 AM
Muck: If indeed you do have an exterior crack in your block and jb weld does not last, there is a process called pinning, I have used several times to repair cracks in cast iron. Have even used it to repair pin holes in a diesel cylinder bore. It involves drilling and tapping small holes beginning and ending just beyond the crack on each end. The first hole is drilled, tapped and a tapered, threaded plug is screwed in and ground flush. The next hole is drilled partly into the plug just installed, forming an interlocking plug in entire length of the crack. Any old time machine shop tech should know the process. Cast iron is very hard to weld unless heated to a high temp and the jb weld is anyones guess. Hope this helps
east tx skier
06-10-2005, 11:11 AM
Edit. Sorry
thanks for all the info on this subject. i will try the jb weld first, then i will look into this pinning at the machine shop.
Thanks again!
Cloaked
06-11-2005, 04:17 PM
(If JB fails) talk to a welder that knows his metallurgy. IIRC I had my motor mounts welded back using a nickel based rod. Cast iron does not have to be heated to a high temp for metal cohesion. A preheat (with a rose bud) of 200 - 350 deg F is all that is needed. The right welder can fix it easily enough and will know the metal properties for the correct procedure.
well i cleaned the area up and found that there are several cracks that i can see. i am going to take it back to the lake to find the exact spots that are leaking and try the JB weld.
i removed the petcock completely and found alot of sand inside the block. that would explain why not very much water came out last fall. i flushed it all out and now i know. i think i really lucked out that the block is not damaged more. the oil is looking fine and i plan to keep an eye on it.
one last question- does this engine have a high temp shut off?
Jerseydave
06-17-2005, 02:40 PM
I think it has a limp-home mode that would limit engine rpm's if it starts to run hot. It should also have a loud warning of some kind if the temp gets too high, just in case you're not watching the temp gauge.
When you winterized it, did you fill the block with anti-freeze? I was told not to leave an engine block empty over the winter just in case there is still some water in it and also the cast iron will rust internally without some kind of anti-freeze to protect it.
If I were you, this fall remove the thermostat, drain all the water out and fill the block and hoses with -100 degree antifreeze from your local boat supply company.
Hope your repair on your block goes smooth.
everyone tells me not to fill this engine with any kind of antifreeze because of the aluminum heads. aparently, antifreeze is bad for the alum.
thanks for the info on the temp.