coolant leak?!?!?
coolant leak?!?!? ok guys ive rebuilt an ls1 so im no noob but where the hell is this coolant leak coming from no smoke in exhaust, tightend all clamps, new 160 t-stat, new waterpump (today), new gaskets.... i saw a steady stream of coolant coming from behind the waterpump pulley so i knew it had to be a bad gasket in waterpump so replaced the waterpump for new one and new gaskets... filled with 2 gal of coolant and took it for a spin.. temp was around 185 which i was damn happy everything was working well and temp was steady even at wot. but pulled home and smoke starts billowing through hood and passenger headlight...... -____________- and what else do i hear, the niagara falls of coolant and there is a steady stream of it coming from the oil pan so its running somewhere down the engine. where else could it be?? thanks guys! 
Check to see if it's coming from the weep hole, which is behind the pulley-just below the pulley.
The shaft seal inside the pump can fail...even on a new one. The leak will show at the weep hole.
A leak here usually happens while the engine is either heating up, or cooling down (expansion/contraction).
The shaft seal inside the pump can fail...even on a new one. The leak will show at the weep hole.
A leak here usually happens while the engine is either heating up, or cooling down (expansion/contraction).
With my car (a 67), there is enough room in front to get an angle to see just underneath the pulley.
You may be able to stick a mirror just below it.
There are 2 types of pulleys. The earlier one has 4 bolts and can be removed. The newer one is pressed on. I dont think it can be removed without special means.
An alternative is to wipe the lower pump area with a tissue/paper towel.
Since the 2 gaskets are on either side of the pump, try wiping those areas to see if there is coolant there.
Did you use the old style gaskets, or the newer rubber-lined ones. The newer ones provide a better seal.
You may be able to stick a mirror just below it.
There are 2 types of pulleys. The earlier one has 4 bolts and can be removed. The newer one is pressed on. I dont think it can be removed without special means.
An alternative is to wipe the lower pump area with a tissue/paper towel.
Since the 2 gaskets are on either side of the pump, try wiping those areas to see if there is coolant there.
Did you use the old style gaskets, or the newer rubber-lined ones. The newer ones provide a better seal.
Thanks for the reply I used the newer ones metal with rubber inside the gaskets.. I'll wipe it down today and try again this issue has been getting annoying and expensive with 5 gal of coolant draining ugh moat likely it'll be fixed today but I hope it's not the coolant crossovers under the intake :/ that will suck lol but it only does this when there is a full 2 gal in system and it loses only one gal I say and the rest stays and keeps engine from over heating
That's alot of fluid.
I wouldn't think that the weep hole or the waterpump shaft would spill that much. Like you say, it could be the coolant crossover.
Do you have the TB coolant/heater hose. Most people bypass it. If you haven't modded it (removed it), maybe that's what is leaking?
I wouldn't think that the weep hole or the waterpump shaft would spill that much. Like you say, it could be the coolant crossover.
Do you have the TB coolant/heater hose. Most people bypass it. If you haven't modded it (removed it), maybe that's what is leaking?
Trending Topics
I remember when we we finished up my rebuild we had forgot to put a ring clamp on the coolant crossover line. Once the motor warmed up she popped the hose off and there went a gallon of coolant. Doesn't leak now though
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
id stick with the metal ones.. never have had a problem with them plus ALOT easier to remove than the paper ones if u need to remove water pump for any reason lol PLUS i found the leak.... -_____- my radiator had a crack on the side of the plastic!!! fixed and no more leaks! i dont know how i missed it
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
Teching In
Joined: Apr 2012
Posts: 15
Likes: 0
From: Maryland
Just replaced the cap and it still shot out...today i come home and there is a puddle of coolant.. seemed like it was coming from the stat. Maybe the stat housing going bad? Or even the water pump? Its killing me
Teching In
Joined: Apr 2012
Posts: 15
Likes: 0
From: Maryland
ok, ran a pressure test leak appeared to be coming from the water pump. Replaced the water pump drove around noticed the temp gauge was not working and is still leaking.
Any ideas of where the leak could be coming from now?
Any ideas of where the leak could be coming from now?
This is like asking "How long is a piece of rope?" Easy to ask, impossible to accurately answer without seeing it. Here's a process that should get you results:
Coolant sprays under pressure, so the location of the drip is not always the source of the leak. The OP's leak was eventually found exactly where he said it wasn't..."tightened all clamps" was right in his first post.
I'd put the car up on ramps or stands, get under it, and put the pressure tester back on. Pump it up to 16# or whatever your cap is rated at, and if you inspect carefully you'll find the leak.
Also...coolant blowing out the radiator or overflow cap is usually a blown head gasket. If the pressure tester can't hold 16# for at least 5 minutes, and there's no externally-visible leak, you'll want to start removing spark plugs and listening in each cylinder for a hiss.
Coolant sprays under pressure, so the location of the drip is not always the source of the leak. The OP's leak was eventually found exactly where he said it wasn't..."tightened all clamps" was right in his first post.
I'd put the car up on ramps or stands, get under it, and put the pressure tester back on. Pump it up to 16# or whatever your cap is rated at, and if you inspect carefully you'll find the leak.
Also...coolant blowing out the radiator or overflow cap is usually a blown head gasket. If the pressure tester can't hold 16# for at least 5 minutes, and there's no externally-visible leak, you'll want to start removing spark plugs and listening in each cylinder for a hiss.