Hey all. I'm new to the forum (literally my first post) and I'm having a problem with my '96 Silverado leaking coolant. So let's start off by saying I have little to no DIY experience. I'm trying to solve this problem without going to a shop (I don't really know/have a go-to shop around me). My truck started leaking (pouring) coolant the other day and I'm not entirely sure where the main leak is coming from. To be perfectly honest, I'm starting to think that there may be a hole in the radiator as well as another, primary leak. Bought this truck about a year back with 201k on it and it's been good to me thus far. I've only put 8000 on it thus far. Only issue I've personally had was the engine coolant lines went out on me about 6 months ago. I replaced both sets of lines, with help, and have had no other problems to date besides the coolant leak.

Here's a bit of the truck's RECENT history. About three months ago I brought the truck in for a routine oil change and was told by the mechanic that there was little to no coolant in the pump. They asked if I wanted to replace the fluid or if I wanted to top off the fluid. I said I would rather replace the fluid and asked if there was any leak. They said there was a SLIGHT leak but it appeared to be coming from my REAR DIFFERENTIAL (they recommended checking the differential fluid levels and replacing the seal). I didn't see any leaks taking the truck home and so I figured they were trying to milk me more money and didn't think anything of it. However recently (about a week or so ago), I saw some minor spotting in the driveway and noticed the temperature gauge was a bit higher than normal. After checking, I realized there was little to no coolant in my pump, again. I poured some more coolant in the truck and the very next day I had a MASSIVE leak underneath my truck. I grabbed another bottle of coolant, and poured it in. I started the truck to try and find the leak, and as SOON as I turned it off the truck started to smoke slightly from underneath the hood. I identified one leak underneath the truck, but was told by my dad that simply didn't make sense. I topped off the coolant, again, and restarted the truck. When I crawled underneath the truck a second time, I noticed coolant practically everywhere... so maybe a hole in my radiator at this point? To make matters worse, I opened the hood and saw a pool of coolant sitting in the fan housing, directly under the fan... so... water pump? I shut the truck off and it started smoking IMMEDIATELY and in a larger amount...

I'm going to upload some images in a few of my initial findings and/or observations. If helpful, I can even upload a video of some of the leaks. I know these trucks are notorious for the water pump as well as the intake manifold gasket leaking (problem is I have NO idea where EITHER are and can't find reliable pictures online). I do have someone who can help me.. but I'd rather not get them involved without at least starting this myself. The person is EXTREMELY busy and I ALWAYS feel bad asking them for help. So if it's possible, PLEASE help! I know this is a bad time of the year for most people.. but ANY help is GREATLY appreciated!!

 

The first couple of pictures are just what I can see under the hood. I DID notice someone (previous owner's mechanic) disconnected my overflow tank from the coolant pump. The rest are where I suspect the major leak (it literally pours out...but I'm not sure if this leak is trailing down from somewhere else?) is coming from UNDERNEATH the truck. Sorry for the weird picture angles... I was literally holding the flashlight in my mouth while I contorted myself under the truck with my tablet to get these shots lol.

 

So, just a quick update... after doing some extensive research online I really do believe the issue is the pesky intake manifold gasket. Tomorrow morning I'm going flush the coolant lines entirely (because the truck currently has Dex-cool in it and after researching online, I'm kind of nervous to continue using it ) and re-top off the coolant. I am going to look in the back of the engine compartment, near the fire-wall, and see if I can confirm the leak. If so, I am going to call around some mechanics (and try to feel some out) because, being fully honest here, this does NOT seem like something I can tackle at the present moment in time. Provided this IS the issue: I'm switching my truck off Dex-cool, will have the overflow tank reconnected, and will have the mechanic install the metal gaskets that came out a few years ago instead of the stock plastic ones. I will keep you all posted as to what happens, and will upload a new picture of the area I used to (hopefully) diagnosis the intake manifold gasket leak (as I haven't really found any video/pictures online showing the leak's location - I only found the location by searching how to replace said gasket).

 

Do you have any coolant in your oil? The oil will be milky white if you do. This usually happens when the intake gasket fails.

 

Sorry, got a bit caught up with the family today. I have not had a chance to check the truck today, but knowing that now, I'll definitely take a look at my oil as well. Thanks for the help oldchevy

 

Quick update: there appears to be no coolant in my oil. The oil is just the normal color. I'm going to throw some more coolant in the truck and see if I can see a leak near the firewall just to rule out the gasket... just curious though, would it leak anywhere else and still be the gasket? I'm also going to pop off the fan shroud and see if I can see where the coolant is pooling in there.

 

Clean everything off as best you can. Start it and watch carefully to see where the coolant is first starting to show up. Be careful the leak could be at one spot and run to another spot before it is noticed. Watch very carefully.

 

Found a leak. My heater hose that runs to the intake manifold was completely rusted out. I bought the replacement part and am waiting for it to come in (next day or so). I am going to do what you suggested though, and clean everything after installing the new hose, just to make sure that there is no secondary leak. That, and I need to clean off the fan shroud and make sure coolant is leaking in there somehow as well.

 

So, I cleaned out the engine bay as best I could like you mentioned Old Chevy. I ended up replacing the heater house and the part that connects the house to the intake manifold.. i think it's called the intake fitting? anyway, I replaced the house and that part since when I took off the hose I noticed that connector looked pretty rotted out as well. Started her up and didn't see any additional leaks as of yet. I also haven't seen any coolant in my fan shroud.. yet. so maybe I overpoured or something? she is running good thus far. Ended up having that snow storm that hit the north east and had to throw my plow on it (yikes!) and so far I haven't had any issues. I think the problem is solved thanks for your help!