Missing antifreeze.....Head gasket or Intake? Does it matter? - Third Generation F-Body Message Boards


Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!

Missing antifreeze.....Head gasket or Intake? Does it matter?

Reply
 
Thread Tools Search this Thread
Old 09-11-2017, 08:55 AM   #1
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Missing antifreeze.....Head gasket or Intake? Does it matter?

Have a 87 5.7 TPI Iroc that keeps losing antifreeze. The PO rebuilt the engine (supposedly) about 9k miles ago. When I got the car I changed all the fluids including radiator and engine block flush. Seemed normal to me to add some fluid to the jug now and then assuming some air was working its way out but that was now 5K miles ago. Shouldn't take that long to stabilize!

Currently the car runs well with no white smoke at startup. The oil also looks great and the level is not changing. It's always bone dry under the car and there is no sign of antifreeze anywhere in the engine compartment. I've only pulled a few plugs just for grins and they all look good also. I am assuming the antifreeze is going out the tailpipe but how do I determine if it is a head gasket or intake gasket. Is there a way to test each seperately? Thanks.
Jimmy2x is offline   Reply With Quote
Old 09-11-2017, 10:51 AM   #2
Supreme Member
iTrader: (12)
 
Tibo's Avatar
 
Join Date: Jun 2003
Location: Desert
Posts: 3,791
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

If it's an intake gasket than the most likely place for coolant to go is in the lifter valley area where it would mix with the oil and you would see the coolant turn a milky color from a hint of brown (not much coolant) to what looks like coffee with a bunch of creamer (lots of coolant). Upon draining it's also possible for the water and oil to separate out like salad dressing and you could drain the oil and then the water on top of the oil. If it is a head gasket leak the most logical place for it to go is the combustion chamber. It would just be burned off there. If he rebuilt it and it is leaking into the chamber it could be a warped head or engine block, incorrectly installed head gasket or another bad head gasket.
Tibo is offline   Reply With Quote
Old 09-11-2017, 11:00 AM   #3
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Thanks Tibo. I'm pretty sure that I know what has to happen.....I gotta tear it all down and find out what I'm dealing with. I just had a small glimmer of hope that maybe there was a way to definitively say it's just an intake gasket. I guess this winter will include some exploratory surgery.
Jimmy2x is offline   Reply With Quote
Old 09-11-2017, 11:51 AM   #4
Supreme Member
iTrader: (12)
 
Tibo's Avatar
 
Join Date: Jun 2003
Location: Desert
Posts: 3,791
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

You can do a leak down test on the cylinders to avoid pulling off both heads.
Tibo is offline   Reply With Quote
Old 09-11-2017, 11:52 AM   #5
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 19,697
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

More likely the water pump.

Head gaskets hardly ever go bad that way. If they're bad, you'll have one or more dead holes, 99% of the time. No dead holes, no gasket failure.

Could be head bolts though... might have to pull them 1 at a time and re-seal them.
sofakingdom is offline   Reply With Quote
Old 09-11-2017, 12:38 PM   #6
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Wouldn't the water pump leave some sign of leaking someplace? I've only ever seen them leak out the weep hole or the pulley shaft itself.

I would certainly believe one or more of the head bolts having an issue. I guess the best place to start would be with the leak down check and hope that I don't have to actually pull the head(s). Any other ideas???? Thanks for the help fellas.
Jimmy2x is offline   Reply With Quote
Old 09-11-2017, 02:20 PM   #7
Supreme Member
iTrader: (18)
 
Drew's Avatar
 
Join Date: Jul 1999
Location: Salina, KS
Posts: 14,049
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Quote:
Originally Posted by sofakingdom View Post
More likely the water pump.
Boom!

Had a coolant consumption problem for a few years, wasn't too concerned since no other symptoms. A couple weeks ago I was under the car for unrelated reasons and noticed the waterpump has clearly been pissing from the weep hole for a while now. Also explains the gunk on the back of the waterpump pulley. No drips since it would sling the leaking fluid off the pulley when the engine was running.
Drew is online now   Reply With Quote
Old 09-11-2017, 02:53 PM   #8
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I drove the car to work today so when I get home I will leave it running and go over that water pump with a fine tooth comb. God, I hope you guys are right! Thanks again.
Jimmy2x is offline   Reply With Quote
Old 09-11-2017, 06:55 PM   #9
Supreme Member
iTrader: (1)
 
Stevolwevol's Avatar
 
Join Date: Nov 2008
Location: Michigan
Posts: 1,643
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

If you pulled the plugs and they all look good, then it's probably not a head gasket, or a cracked head. You would have a clean, pristine looking plug from "wash" from the antifreeze. How does the temp gauge read? Does it fluctuate? An intake gasket could leak, but it may dry before it drips. Do you smell antifreeze after the engine is warm?
Stevolwevol is offline   Reply With Quote
Old 09-12-2017, 07:17 AM   #10
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Temp gauge reads very consistently around 180-185. Checked the water pump all over last night and everything was bone dry. This was after a 26 mile drive. I do smell antifreeze when the engine is warm but the cap on my reservoir tank is an open vent type. But, even with the hood closed you can smell the antifreeze when you shut it off.
Jimmy2x is offline   Reply With Quote
Old 09-12-2017, 09:44 AM   #11
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 19,697
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

The wp leaks from the "weep" (actually, bearing vent) hole behind the pulley.

When it leaks the coolant gets slung everywhere by the pulley when running, but runs down the back bottom of the lower rad hose while off.

Get up under the front of the car and look at the bottom of that hose.
sofakingdom is offline   Reply With Quote
Old 09-12-2017, 10:23 AM   #12
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

When I got home from work last night I parked the car with the front end hanging over the edge of the sidewalk then crawled under it. Everything was bone dry. Hose, weep hole, inside the water pump pulley...everything. I started the car and made sure it was good and warm after running for few a minutes and looked at everything again with a good light while it was still running. Again...nothing, everything dry.

I may just run the car for the next two months until I put it up for winter and see what develops. I would think that something would begin to be more obvious as time goes on. I'm beginning to think I'm losing my mind.
Jimmy2x is offline   Reply With Quote
Old 09-12-2017, 10:25 AM   #13
Senior Member
 
Join Date: Mar 2017
Posts: 881
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Also the rear coolant passages to the intake manifold. The manifold will get pitted up and they become very hard to seal. The coolant leak is hard to spot on the back side of the engine and often dries before it makes it to the floor. I had to bead blast my lower manifold and the fill the pitting with metal filler and block sand it to get a proper seal.
GeneralDisorder is offline   Reply With Quote
Old 09-12-2017, 10:44 AM   #14
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I had not heard of that one before but that is very believable. Would make sense that the antifreeze smell could be from it drying on the hot backside of the motor. Next time I drive it I will have to get my head and a good light in on the back of that manifold. Thank you for the idea.
Jimmy2x is offline   Reply With Quote
Old 09-16-2017, 01:12 AM   #15
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I've had a heater core slow seep cause antifreeze loss, didn't figure it out until it eventually got worse, I changed the heater core and my slow leak prob went away
84 Z-28 350 is offline   Reply With Quote
Old 09-16-2017, 02:25 PM   #16
Member
 
Join Date: Jan 2005
Location: N. CA
Posts: 193
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

How about testing the cooling system for "Products of combustion"? You can buy a dye-test kit for approx. 50 bucks, or find a TRUSTED shop to conduct the test.

Was there a dry stain coming f/ the pump weep hole?
mikeceli is offline   Reply With Quote
Old 09-16-2017, 02:52 PM   #17
Senior Member
 
Join Date: Mar 2017
Posts: 881
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Quote:
Originally Posted by mikeceli View Post
How about testing the cooling system for "Products of combustion"? You can buy a dye-test kit for approx. 50 bucks, or find a TRUSTED shop to conduct the test.
This will generally be evident as an oily black ring of goo inside the overflow bottle.

The chemical tests don't work well. The best way is to use an exhaust gas analyzer.

But if there's no oily ring, or loss of compression, then this is highly unlikely to be a HG problem. My vote is still lower intake manifold coolant passages at the back of the heads.

GD
GeneralDisorder is offline   Reply With Quote
Old 09-16-2017, 03:00 PM   #18
Supreme Member
iTrader: (1)
 
Stevolwevol's Avatar
 
Join Date: Nov 2008
Location: Michigan
Posts: 1,643
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I replaced my intake gasket cause it was leaking, but it was in the front. It took awhile to notice. At first I saw nothing cause of evaporation, but as the gasket leaked more, I could visibly see a small pool of green, but it wasn't dripping on the ground. If your car has the original gasket then this may be the case.
Stevolwevol is offline   Reply With Quote
Old 09-16-2017, 06:43 PM   #19
Senior Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 947
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

There are coolant pressure testers that you can buy or maybe rent.

Or you could even use the DIY method.
NoEmissions84TA is offline   Reply With Quote
Old 09-16-2017, 07:25 PM   #20
Senior Member
 
Join Date: Mar 2017
Posts: 881
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Valve stem in the radiator cap. Nice. I would suggest a bicycle pump. If you use a compressor it would be very easy to go over 15 psi and blow the radiator tank or hoses out.

GD
GeneralDisorder is offline   Reply With Quote
Old 09-16-2017, 10:05 PM   #21
Senior Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 947
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Quote:
Originally Posted by GeneralDisorder View Post
Valve stem in the radiator cap. Nice. I would suggest a bicycle pump. If you use a compressor it would be very easy to go over 15 psi and blow the radiator tank or hoses out.

GD
True. Another concern is if you have a blown head gasket leaking into a cylinder.
You have the potential to hydro-lock the engine and bend a connecting rod if cranked.
NoEmissions84TA is offline   Reply With Quote
Old 09-16-2017, 10:39 PM   #22
Senior Member
 
Join Date: Mar 2017
Posts: 881
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Quote:
Originally Posted by NoEmissions84TA View Post
True. Another concern is if you have a blown head gasket leaking into a cylinder.
You have the potential to hydro-lock the engine and bend a connecting rod if cranked.
I haven't encountered the starter motor with a sac big enough to actually bend a connecting rod just from cranking. Not saying it isn't possible but the only bent rods from hydro lock I've seen were running engines that ingested large amounts of water. I've hydro locked a few motors with gasoline from stuck injectors, etc and in those cases the engine survived or at least didn't bend a rod. Wiped out a rod bearing on one of them.

GD
GeneralDisorder is offline   Reply With Quote
Old 09-17-2017, 09:33 AM   #23
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 19,697
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Head gaskets are almost NEVER responsible for mystery coolant loss, in this type of engine.



Here's what one looks like, with the holes marked. Sorry the photo is so big, I didn't realize that until after I posted it. Copy it and paste it into Paint or something to see the whole thing.

Cyan is the "steam holes" for a 400, which your gasket doesn't have. Red is the dowel pin holes. Yellow is the bolt holes. Light grey is oil drainback from the rocker arms. All others are coolant. The magenta ones are the most important... they cool the hottest bit of casting in the whole engine, which is, the part of the head between the 2 center exhaust ports... that was what I originally posted this photo to explain to somebody.

Now, LOOK AT the various spacings of things in that gasket, and consider the pressures. Coolant is under 15 psi or so; combustion is in the 1200 - 1500 kind of range. THIMK: if that gasket is going to fail, WHERE is it most likely to do so? Would it not be where 2 1500 psi chambers (aka "cylinders") are right next to each other with only a very narrow strip of material separating them?

This is why, when a gasket fails, it ALMOST ALWAYS affects the way the engine runs. They fail between cylinders, the thin places in those cyan rectangles with the steam holes, and VERY RARELY anywhere else.

Put head gasket failure out of your mind.

Bolts are a different matter... on every single one of them, all 17 per side, the threads are exposed to coolant. If the builder used an inappropriate sealer such as RTV on them, or no sealer at all, then they are VIRTUALLY 100% IRONCLAD GUARANTEED to leak. Which is why I suggested pulling every one, one at a time, and putting some thread sealer (my preferred stuff is the "high temp automotive thread sealer with Teflon" from Permatex or Loctite, same company, whichever brand the label says) on their threads and under their head, and re-torqueing them to 60 - 62 ft-lbs. DO NOT use a "clicker" type wrench. Use a beam or dial type. MAKE SURE you measure the torque while the bolts are actually turning, i.e. DO NOT make the mistake of setting them by their "breakaway" torque. ABSOLUTELY NO MORE THAN 65 ft-lbs: if the torque exceeds that while the bolt is moving, back it out, put more sealer on it, re-torque.

I like that valve stem in a rad cap... so simple and basic and cheeeeeeeep, yet perfectly functional. However a leak typically has to be pretty yuuuuuujjjjjjje to be detectable that way.

The intake gasket is a very good suggestion also. Depending on what kind was used, they can easily fail. The cheeeeep paper-ish ones are total crap and are almost certain to fail rapidly. It will be obvious if they have failed, when you pop the intake off.

If it was mine, I'd pull the intake and exh manifolds, and the valve covers; do the bolts; and make sure the intake goes back on PERFECT. I'll be happy to detail how to do that in a separate post when you get to that point.
sofakingdom is offline   Reply With Quote
Old 09-18-2017, 01:10 AM   #24
Supreme Member
iTrader: (18)
 
Drew's Avatar
 
Join Date: Jul 1999
Location: Salina, KS
Posts: 14,049
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Quote:
Originally Posted by Jimmy2x View Post
I do smell antifreeze when the engine is warm but the cap on my reservoir tank is an open vent type. But, even with the hood closed you can smell the antifreeze when you shut it off.
Umm, no. You're not going to smell antifreeze from the vent in the reservoir cap. But you would smell antifreeze inside the car, from a leaking heater core.

If you can smell antifreeze, you should be able to see that antifreeze. Good bright flashlight and look around thoroughly the next time you smell antifreeze. Rub your hand over the carpet under the passenger's side of the dash, too.
Drew is online now   Reply With Quote
Old 09-18-2017, 05:45 AM   #25
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

The smelling antifreeze thing makes me vote for the heater core too
84 Z-28 350 is offline   Reply With Quote
Old 09-18-2017, 07:07 AM   #26
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Thank you for all the ideas fellas. Although I do smell antifreeze when I shut off the vehicle, it is not on the inside of the car, and it is not really strong.

I have checked the carpet and up under the dash on the passenger side and everything is dry. Any other places that heater could be leaking?

Not knowing what the PO did to the head bolts during the rebuild that seems to be a good place to poke around. But, if those bolts have worked their way loose, where would the antifreeze be going?

Sofakingdom I appreciate the support (and free education) and may be sending you a PM when I tear into the car this winter.
Jimmy2x is offline   Reply With Quote
Old 09-18-2017, 07:14 AM   #27
Supreme Member
iTrader: (1)
 
Stevolwevol's Avatar
 
Join Date: Nov 2008
Location: Michigan
Posts: 1,643
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Is you windshield getting fogged up? A leaky heater core will do this early on before your it starts dripping on the carpet.
Stevolwevol is offline   Reply With Quote
Old 09-18-2017, 07:33 AM   #28
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Not that I have noticed. 56 degrees this morning on the way to work so temps should have been ideal with that cool windshield.
Jimmy2x is offline   Reply With Quote
Old 09-18-2017, 09:48 AM   #29
Junior Member
iTrader: (9)
 
Join Date: Jun 2002
Location: Altus, Oklahoma
Posts: 99
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I suspect the heater core also. Just to rule it out without changing it, loop the two heater hoses to bypass the heater core. Basically, remove the hoses from the heater core and put them together, end to end. Will have to buy an adapter for about $5 at a parts store because they are two different size hoses.

If the problem goes away, the heater core is bad. It's a frustrating "process of elimination".

Make sure to post your results. Many don't.....
tater is offline   Reply With Quote
Old 09-18-2017, 11:59 AM   #30
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Nice idea Tater. That would eliminate one possible suspect. Cheap and easy too! thank you.
Jimmy2x is offline   Reply With Quote
Old 09-18-2017, 06:28 PM   #31
Senior Member
iTrader: (2)
 
Join Date: May 2013
Location: Milford, CT
Posts: 964
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Wondering if the previous owner used thread sealant on the head bolts when rebuilding the engine.
TylerSteez is offline   Reply With Quote
Old 09-18-2017, 06:48 PM   #32
Senior Member
 
NoEmissions84TA's Avatar
 
Join Date: Feb 2017
Location: Meriden, CT 06450
Posts: 947
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Be EXTREMELY careful when removing those hoses. If you pull and twist too hard, then YOU WILL be replacing the heater core.
NoEmissions84TA is offline   Reply With Quote
Old 09-18-2017, 07:37 PM   #33
Supreme Member
iTrader: (1)
 
Stevolwevol's Avatar
 
Join Date: Nov 2008
Location: Michigan
Posts: 1,643
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

If the heater core is leaking, you will smell antifreeze inside the car, and you WILL get fog on the inside of your windshield. Is the smell strong inside the car, or under the hood???
Stevolwevol is offline   Reply With Quote
Old 09-19-2017, 08:23 AM   #34
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Smell is only under the hood. Don't think its the heater core. Temps were in the low 80's today on my way home and I stuck my nose up under the dash and all over the carpet. Even pulled up the carpet to smell and look at the pad. No smell, no moisture. Pretty sure it's not the heater core.

Various individuals have suggested that there was no sealer or poor sealer used on the head bolts during reassembly. Assuming this is the case, where would the antifreeze be going?
Jimmy2x is offline   Reply With Quote
Old 09-19-2017, 08:37 AM   #35
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

It would ooze out of the heads of the bolts, and probably evaporate before it would be noticed...I had a similar problem...the ones to really worrie about are the ones under the valve covers, they will turn to sluge in nothing flat and you'll never notice it in the pan, if it's leaking from the ones under the exauast manifold/headers it won't hurt anything but it is a pain in the *** to get at
84 Z-28 350 is offline   Reply With Quote
Old 09-19-2017, 08:46 AM   #36
Supreme Member
iTrader: (1)
 
Stevolwevol's Avatar
 
Join Date: Nov 2008
Location: Michigan
Posts: 1,643
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Quote:
Originally Posted by Jimmy2x View Post
Smell is only under the hood. Don't think its the heater core. Temps were in the low 80's today on my way home and I stuck my nose up under the dash and all over the carpet. Even pulled up the carpet to smell and look at the pad. No smell, no moisture. Pretty sure it's not the heater core.

Various individuals have suggested that there was no sealer or poor sealer used on the head bolts during reassembly. Assuming this is the case, where would the antifreeze be going?
When the engine gets warm the antifreeze will evaporate before it hits the ground, if it's leaking in small amounts. On my earlier post I explained about my intake leaking in the front, and I could see a very small amount of green pooling up, but it evaporated before it dripped. If your intake is leaking toward the back of the engine, you wouldn't be able to see it. You would smell it though.

If this is your original intake gasket, it stands to reason yours could be leaking. It's not catastrophic engine failure, and it can be fixed with a little elbow grease. It is of course necessary to rule out other leaks before replacing anything.
Stevolwevol is offline   Reply With Quote
Old 09-19-2017, 09:10 AM   #37
Senior Member
iTrader: (1)
 
Tootie Pang's Avatar
 
Join Date: Aug 2009
Location: Los Angeles
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

How often and how much does it need when it needs a coolant refill?
Tootie Pang is offline   Reply With Quote
Old 09-19-2017, 10:17 AM   #38
Junior Member
Thread Starter
 
Jimmy2x's Avatar
 
Join Date: Nov 2015
Location: Kingsley, MI
Posts: 31
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I started keeping track of level and mileage when I originally started this thread. I have put about 300 miles on the car and this morning with the engine cold it was down about 1/4 to 3/8 of an inch in the overflow jug. I haven't been adding any until it was at least an inch below the full cold line but like I said I wasn't watching my mileage before.
Jimmy2x is offline   Reply With Quote
Old 09-19-2017, 10:20 AM   #39
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

That's a small leak..that will be hard to find
84 Z-28 350 is offline   Reply With Quote
Old 09-19-2017, 11:11 AM   #40
Senior Member
iTrader: (1)
 
Tootie Pang's Avatar
 
Join Date: Aug 2009
Location: Los Angeles
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Agreed.
Tootie Pang is offline   Reply With Quote
Old 09-19-2017, 11:31 AM   #41
Junior Member
 
Join Date: Aug 2015
Posts: 73
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Pick up some fluorescent coolant dye GM part #12378563 or after market. Pour about 1/2 the bottle into radiator. drive or aleast get thermostat to open, use black lamp and the dye will glow green. I use it all the time at work and at home.
Joe
JA411 is offline   Reply With Quote
Old 09-20-2017, 06:14 AM   #42
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I need to do that to my wife's Chevy Tahoe lol
84 Z-28 350 is offline   Reply With Quote
Old 09-20-2017, 06:41 PM   #43
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 19,697
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

If yer Hoe has a 5.3 with 706 casting heads, it's probably this.



All of the truck boards are full of the same complaint; Castech 706 heads that crack right above the head bolts. It's an epidemic. Chevrolet refuses to acknowledge the existence of the problem, let alone accept responsibility / accountability for it. What a bunch of weeeeeezelz.

The one in the photo is a 2004 Avalanche with a LM7.

If your Hoe puffs a GIANT blast of oil smoke when it starts up in addition to the slow coolant loss, and the oil pressure seems to go away REAL QUICK after an oil change, suspect the head crack.
sofakingdom is offline   Reply With Quote
Old 09-20-2017, 06:45 PM   #44
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 19,697
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I forgot: Steve, 9 head bolts are inside the crankcase (7 long, 2 medium), therefore those leak into the oil; and 8 (all short), all in a nice row right under the exhaust manifold, communicate with the outside world.
sofakingdom is offline   Reply With Quote
Old 09-20-2017, 07:09 PM   #45
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

I already changed out the heads they were the castech casting.....it's dripping off the harmonic balancer but other than the drips and water loss there's no evidence of the sorce....I'm thinking the water pump, but I want to be sure before I change it

Last edited by 84 Z-28 350; 09-20-2017 at 07:27 PM.
84 Z-28 350 is offline   Reply With Quote
Old 09-20-2017, 07:32 PM   #46
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 19,697
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

Probably not the WP, but could be of course.

The WP and TC gaskets for the water passages are equally notorious for leaking. Although to be honest, if I took off the WP to change the gaskets, then that must mean it's been on there for AHELLUVA LONG time; I wouldn't put it back in that case, even if it was "good", I'd refresh it. Similarly if I took off the TC I'd put a 10296 oil pump and a new pickup tube O-ring in it. Oh wait... I already did just exactly that.
sofakingdom is offline   Reply With Quote
Old 09-20-2017, 07:47 PM   #47
Senior Member
 
Join Date: May 2001
Location: Tucson, AZ (deployed to Saudi Arabia)
Posts: 663
Re: Missing antifreeze.....Head gasket or Intake? Does it matter?

This will be my first time diving into the front of a ls engine, the heads were a PITA, hopefully the front is eaiser, I guess I'll find out when I get back to the US in oct/nov
84 Z-28 350 is offline   Reply With Quote
Reply


Go Back   Third Generation F-Body Message Boards >

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Advertising
Featured Sponsors
Vendor Directory

1982 Camaro '82 || 1983 Camaro '83 || 1984 Camaro '84 || 1985 Camaro '85 || 1986 Camaro '86 || 1987 Camaro '87 || 1988 Camaro '88 || 1989 Camaro '89 || 1990 Camaro '90 || 1991 Camaro '91 || 1992 Camaro '92


All times are GMT -5. The time now is 05:26 AM.


All content copyright 1997 - 2014 ThirdGen.org. All rights reserved. No part of this website may be reproduced without the expressed, documented, and written consent of ThirdGen.org's Administrators.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: