Why is my truck drinking coolant?

[texmex]

I have a 96 k1500 auto vortec 350 148k. It goes through about a gallon of coolant every three weeks. There are definately no external coolant leaks. When I run it cold there is a noticable clicking noise until it is completely warmed up then it becomes only a slight clicking noise.

Also I noticed recently at idle (about 500-600rpms) the oil pressure only reads about 22 psi. Is this normal?

Please Help.

[chevytrucks92]

Originally Posted by texmex

I have a 96 k1500 auto vortec 350 148k. It goes through about a gallon of coolant every three weeks. There are definately no external coolant leaks. When I run it cold there is a noticable clicking noise until it is completely warmed up then it becomes only a slight clicking noise.

Also I noticed recently at idle (about 500-600rpms) the oil pressure only reads about 22 psi. Is this normal?

Please Help.

You need to check your oil and see if it has any water/coolant in it. If it does, it will have a milky color and have alot of foam in it. IF you find this to be the case, then there's a couple things that could be causing it. The simpliest would be a blown intake gasket. It could also be a blown head gasket.

The worst case scenerio however is a cracked block/head or a warped head.

The best thing to do is park the truck untill you can determine the cuase of the problem. If not, then you will destroy the engine, if you've not already.

[TexasF355F1]

If its not ending up on the ground, then its going into your engine and well your engines gone. This just happened to my dads van. It was a blown head gasket. Do what CT said. But id say its a pretty safe bet that your engine is probably gone.

[JohnnyR17]

I have to disagree respectfullly Texas F355. Your engine is not necessarily gone.

Like Chevytrucks said, check your oil immediately. If its 'milked' - foamy and anywhere from light brown to almost white in color, then you have a serious problem and should consider finding alternative transportation becuase that engine would be pulled immediately - if it were mine. It is important to not run an engine with coolant in the oil because the coolant does not provide the lubrication that engine oil does and the bearings will wear very quickly.

22 psi at idle is fine and would not make me nervous. 5psi will get you down the road.

One gallon every three weeks is a serious leak. First, park the truck over a paved area and check for massive coolant leaks. If no leaks, I would pull the intake off. Carefully inspect the gaskets, see if the gasket could let coolant get from the coolant passage into. If those are fine, its time for head gaskets. Any capable novice mechanic can do this at home, but its best to call a buddy who has done it before for guidance. If you decide do change head gaskets by yourself, post again and we will guide you through it. Good luck!

[broughy84]

your lower intakes are leaking! It's VERY common.

[texmex]

first off, thanks for the responses.

i just checked the oil for coolant contamination and it looks fine. Something I forgot to mention before, a few months ago I changed the O2 sensors and they were somewhat white. Could this mean that some how the coolant is leaking into the intake and getting burned up with the gas?

[Riche]

it is evaporating off the intake,
Lower gaskets and heater hose coupling prob. need replacing.
look at one of my prev. posts

[Silverado Brethern]

I had a dealer try to sell me a truck like that, actually they did but i made them fix it first. My problem was a nearly completley busted gasket that cause bad over heating and actually blew the top off the coolant reserve and fried holes in the radiator. I would say just a precaution remove the intake and look and see what condition the gaskets and such are in cuz at this point i'd say ur lucky it still running.

[z28dw]

hey my truck is doing the same thing and my 93 did it also and it was the intake but this vortec motor looks harder to get the intake off, let me know how hard it is or any precautions I should take because this intake has a lot more sensor and othe junk then my 93 throttle body injection also please let me know I any of you had a problems doing this
thanks for any help

[Cadillakin'98]

You have a pretty serious problem somewhere texmex. And I hope we can help you get it fixed.

First things first: PARK THE TRUCK UNTIL ISSUE IS RESOLVED- Even if you just want to go to the corner store, walk. The more you drive it right now, rthe greater the chance of loosing that motor (if not already)

2nd step: Find root of problem. I have some ideas and suggestions not yet mentioned here. With your truck PARKED, and radiator full (just use water for now-no need to waste $$) get a fairly big sized piece of cardboard, and lay it on the ground under the motor. Make sure the cardboard is big enough to be under the radiator to the tranny, and from the left wheel to the right wheel. Use a couple of pieces if necessary, and weigh them down with bricks or something. I know you said there were no leaks that you could see. I suggest the cardboard thing just to make sure. Leave it parked for a couple of days then check it. The cool thing about this is if there IS a leak, wherever it dripped at, you will have a definate location to inspect under the hood. Also, keeps the driveway clean!

Wouldn't be a bad idea to drain just a little oil just to double check that as well. If you just looked at the dipstick then it may have been unoticable.

If no drips are found on the cardboard and oil still looks like oil, make sure radiator is still full, run truck @ operating temp for approx 5 to 10 min (shut motor if it starts overheating) Open the radiator cap and see if it looks milky in there. What was described from previous post is what you are looking for. Basically make sure you have green or pink fluid ONLY in radiator, depending on which type of antifreeze you are using.

Gotta run right now, but heres some things to try. Keep us posted. I'll keep checking post periodically to give you some guidance if possible.

[texmex]

It ended up being a blown lower intake manifold gasket. had to remove the valve covers to get the intake off because the covers were overlapping the lower intake manifold. Hopefully this solves the coolant leak. This dex-cool is some corrosive stuff. I'll keep yall posted if the leak persists. I've only had it back for a day so we'll see.