Can't catch a break?!

[95OBSMan]

Subject 1995 GMC 5.7 TBI 2wd RCSB

After posting about weak heat in cab, and finding what is the most likely cause, I discovered a coolant leak at the intake manifold, no problem as I found a great write-up on that fix, so I decided to wait on the back flush of heater core until all parts have hit the house related to the intake and do the needed work all at one time, well low and behold now I find a new leak at what appears to be between the cylinder head and block!!! GREAT!! Intake manifold leak is at the front left side, coolant leak for the head/block is on the same side, I'm guessing that I'm not that lucky that this is coming from just the intake? 114k on her and hasn't been monkeyed with, no steam or smell of coolant in exhaust, runs great other than lack of heat in cab(this will be fixed soon), is a head gasket leak in that area common for this year of motor? If not since intake is coming off, pull both heads and new gaskets, if that is the case it "shouldn't" have any "bad" effects on the motor, if the option here is head gaskets, Fel-Pro? OEM? Its just a daily, I just can't believe with 114k on the clock a head gasket has hit its end, guess you win some lose some, any info and or opinions will be greatly appreciated!

 

[Komet]

You need to figure out exactly where it's leaking, could be as harmless as a loose knock sensor or something.

 

[RichLo]

I highly doubt its a head gasket!

Get a coolant pressure tester kit first. Pump it up and let us know

xc_hide_links_from_guests_guests_error_hide_media

 

[NickTransmissions]

Subject 1995 GMC 5.7 TBI 2wd RCSB

After posting about weak heat in cab, and finding what is the most likely cause, I discovered a coolant leak at the intake manifold, no problem as I found a great write-up on that fix, so I decided to wait on the back flush of heater core until all parts have hit the house related to the intake and do the needed work all at one time, well low and behold now I find a new leak at what appears to be between the cylinder head and block!!! GREAT!! Intake manifold leak is at the front left side, coolant leak for the head/block is on the same side, I'm guessing that I'm not that lucky that this is coming from just the intake? 114k on her and hasn't been monkeyed with, no steam or smell of coolant in exhaust, runs great other than lack of heat in cab(this will be fixed soon), is a head gasket leak in that area common for this year of motor? If not since intake is coming off, pull both heads and new gaskets, if that is the case it "shouldn't" have any "bad" effects on the motor, if the option here is head gaskets, Fel-Pro? OEM? Its just a daily, I just can't believe with 114k on the clock a head gasket has hit its end, guess you win some lose some, any info and or opinions will be greatly appreciated!

You can also conduct a block test to see if there's hydrocarbons in the coolant...the test kits are available on Amazon for $20-$30. Between these and pressurizing the system like @RichLo suggested should be more than enough to rule in or out a head gasket/head issue. AFAIK, those engines are not known to blow head gaskets with low mileage...

 

[Orpedcrow]

Could be the same leak, just running along the space between the head and block due to surface tension.

 

[Hipster]

ditto... more diagnostics before assumptions, and a compression test might tell a tale of a blown HG.

 

[95OBSMan]

Thanks guys!! Orpedcrow & Hipster both of you are right, jumped the gun thinking the worst and didn't shine some light on the subject!!! I don't know why I always think the worst!!! So I let the truck sit outside last night because I gave it a really good degreasing and do to the smell my better half said NO WAY is that smell coming into the house ( garage attached to the house) and most of today after honey do's have been done, then time to fire her up and bring it into the garage and thats when I saw what I thought was another leak, but after letting it run and get to temp, then shut it off, cause of the fan blowing, thats when I saw it doing what Orpedcrow said, I'm going to take some pics right now, then I'll post them...

 

[Hipster]

Thanks guys!! Orpedcrow & Hipster both of you are right, jumped the gun thinking the worst and didn't shine some light on the subject!!! I don't know why I always think the worst!!! So I let the truck sit outside last night because I gave it a really good degreasing and do to the smell my better half said NO WAY is that smell coming into the house ( garage attached to the house) and most of today after honey do's have been done, then time to fire her up and bring it into the garage and thats when I saw what I thought was another leak, but after letting it run and get to temp, then shut it off, cause of the fan blowing, thats when I saw it doing what Orpedcrow said, I'm going to take some pics right now, then I'll post them...

I'm pessimistic by nature. Plan for the worst and it's a pleasant surprise when you find less. lol

 

[Orpedcrow]

I don't know why I always think the worst!!!

I take prescription drugs for that same thing. It’s almost always way more trivial than I make it out to be

As a related note, I was only able to find the good intake gaskets (the metal ones with the bonded rubber) to be available in the big upper intake kit that fel-pro makes. The plastic gaskets are garbage.

Edit: I forgot you were tbi, I think they’re different gaskets.

Double edit: @someotherguy has a very detailed TBI intake gasket write up stickied somewhere

 

[Road Trip]

I'm pessimistic by nature. Plan for the worst and it's a pleasant surprise when you find less. lol

^^^^
@Hipster nailed it - this is the only way to approach the 'driving old' hobby.

When getting to know a 'new to you' vehicle, it oftentimes pays to
actually "look for trouble" as opposed to just assuming everything is
OK. Especially on older vehicles like these GMT400s. Even though it
only has ~1/2 the miles on it that my truck has while sitting in my driveway.

Change all the fluids and look for signs of distress. Really inspect the brakes,
even if they seem to work well and don't misbehave. (Perfect example - on my
new-to-me '99 3/4 ton truck the brakes acted flawlessly, so I wasn't going
to touch them. But if you look over HERE you will see what a mistake that
mindset was.) Same thing for the steering & suspension. Clean all the grounds.
Lube the door hinge pins. And if the hood release is stiff, go ahead & oil the
hood latch mechanism now, so that it won't decide to freeze up and deny you
access IF you really need to get in there while on the side of the road.)

I could go on & on, but this is all common sense. Once you've really looked
for trouble and got it all sorted out, you'll get to drive much more
relaxed when behind the wheel.

Best of luck with your '95 RCSB --