1996 350 Vortec Coolant Leak

[adray96]

Hey everyone, when I first got this truck, I noticed that the recovery tank was empty, but didn't notice any over heating. The next day, I filled the recovery tank, met my cousin a half hour away to hang out for a few hours, then drove home. I checked the recovery tank, and it was empty again. I didn't notice any over heating, but the radiator looked pretty full. I figured it wasn't a huge deal and left it like that, it was fine.

The weekend after that, I took my other car to the city for a weekend for easier parking and let the truck sit for a few days. I got home on Sunday, and took my truck to get gas. On the way to the gas station, my SES light came on flashing, and after a moment it just stayed on, but I smelt coolant. When I got home and let the truck cool off, I checked the radiator. The coolant was a little lower, but not a significant amount, and the only code that popped up was a P0301 cylinder one misfire. Next time I started the truck, later that day, the SES light was off and I didn't smell anymore coolant. Everything seemed fine, so I drove the truck like that for a little while more.

Well, yesterday, my girlfriend and I went to the beach an hour away. The SES light was illuminated for the first time in a couple weeks, I just figured it was the P0301 again, I have plugs, wires, cap, and rotor to put on, so I wasn't too worried. We were there for a few hours, then went back to my buddies place about 20-30 minutes away, then drove the hour home. It was the farthest and longest I've driven the truck since I've had it. I put some more coolant in the recovery tank before we left, because I wanted to see if it would leak out again. I checked the recovery tank before leaving the beach, and it was empty again. I didn't notice any overheating or anything. When I got home, I ran the codes again and a P0301 came up (I never erased it from before), and a P0430 for the bank 2 catalyst. I don't think that's related to the coolant problem, but I wanted to include it just in case. I just erased them and waiting to see if the come back. That'll be a separate thread for later, though.

The morning, I went the library, went in for five minutes, came out and saw the truck making a puddle of coolant. Went home, checked the radiator, and it was a little lower than it was yesterday. It's leaking pretty good. It's hard for me to pinpoint exacty where it's coming from, but it looks like it's coming from the driver side rear of the engine, and leaking down the front driveshaft, and dripping off the trans. The oil looks pretty normal, and from what I can see, the heads look pretty dry, and the recovery tank, and the hose from the tank to the radiator look pretty dry. I have some not so great pictures, but I'll try posting them when I can.

I'm sorry for the nice, long essay, but I figured it'd be best to tell you the whole experience I was having from start to current. Does anyone have any clue as to what it could be?

Thank you in advance.

 

[adray96]

Pictures, like i said, they aren't the greatest. Probably won't be much use:

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[skylark]

Most likely the intake. Super common. Order the felpro m98000t.

 

[adray96]

Intake gasket? I've a had a few people it may be a hose or something that runs along the rear of the engine, and connects to the intake.


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[Justin S]

The only "hose or something" that runs near the firewall would be the heater core hoses, and they're on the pass side, that leak looks like driver's side, so i'd go with intake gasket if leaking from above the head, or head gasket if leaking from between

 

[Justin S]

Oh, and a P0430 means that the pass side converter isn't convertering enough and will probably need replacing.

 

[adray96]

It's hard to tell, I'll try looking harder tomorrow, but the head looks okay. I couldn't find the leak at all looking from the top. If definitely look more tomorrow, though. It sat for about 7.5 hours while I was at work. The puddle is a lot smaller than it was. Before leaving for work, I moved the truck from the driveway to the street so my dad could get his car out of the garage. It was definitely dripping more with engine running. I'm guessing a gasket as well.

I don't know if I'll be able to do either the intake or head gasket on my own at home. How difficult would it be? I maybe have the dealership I work at do it


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[Jrgunn5150]

It's hard to tell, I'll try looking harder tomorrow, but the head looks okay. I couldn't find the leak at all looking from the top. If definitely look more tomorrow, though. It sat for about 7.5 hours while I was at work. The puddle is a lot smaller than it was. Before leaving for work, I moved the truck from the driveway to the street so my dad could get his car out of the garage. It was definitely dripping more with engine running. I'm guessing a gasket as well.

I don't know if I'll be able to do either the intake or head gasket on my own at home. How difficult would it be? I maybe have the dealership I work at do it


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Replacing the intake gaskets, is probably a 5 or 6 on a scale of 10. It takes a while, and there are alot of thing's in the way. If you're inexperienced, maybe the techs where you work will help you. With all the mods you have planned on your Z28, you'll need the experience, or a big pocket book.

 

[adray96]

True about the Z28, is like to do all of that myself, for the most part. With the Z28, though, that won't start until I have space in the garage to keep it, hopefully soon. So, when I tear that apart, it'll be in the garage, it won't be daily driven, so I can come back to it, and take my time with it.

The truck is supposed to be a driver. I took my car to work yesterday, but the front breaks are getting kind of bad, I think a caliper is partially closed. So, both cars are kind of weakened at the moment.

Another thing, most of my tools are at work, so I was also going to rebuild my tool collection, replacing my craftsman stuff at work with Snap-On/Matco, and bring the craftsman home.

I watched a 33 minute video on how to remove the lower intake manifold, and it does look pretty daunting. The most involved thing I've don't so far was replacing my rear pads, rotors, and hoses on my Z28. If I do the gasket myself, I'll probably have to do it in the street, or wait till next week and put it in the driveway while my mom is out of town for work.

Dumb question time: I know it probably shouldn't be driven at all, but if I needed to, will the truck be okay to drive? Obviously not long distances, and I have some coolant in the back of the truck


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[Biggershaft96]

True about the Z28, is like to do all of that myself, for the most part. With the Z28, though, that won't start until I have space in the garage to keep it, hopefully soon. So, when I tear that apart, it'll be in the garage, it won't be daily driven, so I can come back to it, and take my time with it.

The truck is supposed to be a driver. I took my car to work yesterday, but the front breaks are getting kind of bad, I think a caliper is partially closed. So, both cars are kind of weakened at the moment.

Another thing, most of my tools are at work, so I was also going to rebuild my tool collection, replacing my craftsman stuff at work with Snap-On/Matco, and bring the craftsman home.

I watched a 33 minute video on how to remove the lower intake manifold, and it does look pretty daunting. The most involved thing I've don't so far was replacing my rear pads, rotors, and hoses on my Z28. If I do the gasket myself, I'll probably have to do it in the street, or wait till next week and put it in the driveway while my mom is out of town for work.

Dumb question time: I know it probably shouldn't be driven at all, but if I needed to, will the truck be okay to drive? Obviously not long distances, and I have some coolant in the back of the truck


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Truck will be fine to drive just make sure to keep coolant in it. Another thing to do is a mpfi upgrade while you have the intake off. I know its kind of expensive but it will save you from having to take it off again to change out the spider injector later and they are about as common to go out as intake gaskets. Its literrally a direct swap.
https://www.amazon.com/gp/aw/d/B000...words=mpfi&dpPl=1&dpID=41coXxE-dEL&ref=plSrch