Boy, the jimmy is really piling it on this week. Things are breaking faster than I can fix them!

Thanks to Captain Hook and a few other good men my brake system is good for the most part.

While doing the rear brake caliper replacement and bleeding, I noticed the rear axle is leaking. I can't tell if it's at the cover or if it's leaking down from the axle seal and just dripping at the cover. I replaced the rear axle diff cover when I first got the car 2 years ago and put everything at torque specs, so I doubt that's it. I topped the axle off with 80/90 oil, it didn't need much.

My big concern is leaking radiator fluid. I don't know if it's internal or external, all I know is that I'm losing radiator fluid and it's getting worse. I'm not sure if it's related, but the A/C does not blow cold at all. The car's idle can be pretty rough at some times, and my mileage is 17mpg on a good tank. From what I've read in previous posts, this all points towards a bad intake manifold gasket, but I want to make sure before putting in all that work. I'd hate to tear everything apart just to find that the problem was elsewhere.

I noticed the leak first when my dad angrily (jokingly) pointed out that my car was leaking on the driveway. The spot it leaves is a 6" diameter circle, not much at all. BUT, so far this summer, including today, I've had to pull over and add coolant. I've already done a radiator flush this summer too, by the way.

What are the best ways to verify where the leak is? I checked the water pump, the seepage hole doesn't seem to be wet. I don't want to make a mechanic waste his time looking at my car, because I know I wont give him any business because I do these repairs myself.

 

Pull your dipstick, does it smell like coolant? Smell like coolant on the oil cap? Does the oil look milky? Do you smell coolant in the exhaust? Those are all ways of checking if its an internal leak. I assume your overflow tank is empty?

 

If you have to do head gasket you're going have to do manifold gaskets anyway. A cooling system pressure tester will let you know if have a leak. Pumping up the pressure with tester will pump up the pressure in the entire cooling system. An external will usually show itself in about 5 minutes. If you can't find the leak and system doesn't hold pressure, depressurise the tester and start the engine with the tester on the radiator. A head gasket leak will cause combustion gases to leak in the cooling system and built up pressure in the cooling system and you will see it on the pressure gauge.

A low tech method for head gasket leak (if can't get hold cooling system pressure tester) is pull the radiator cap off and watch to see if coolant "boils" cold.

Because your truck is "spotting" on the driveway it may be head gasket failure. If it is you'll get new manifold gaskets anyway. The only way to test for leaks is cooling system pressure tester. Also, if have a head gasket failure you probably also have a couple of dead cylinders which would explain the drop in fuel economy and a rough idle.

 

I don't think the leak is related to a head gasket leak, I've never seen separation in the oil. I rented a cooling system pressure tester from autozone yesterday evening.

I just went out to the driveway, popped the hood, and removed the air cleaner assembly up to the throttle body and the ac compressor so that I could better see the cooling components once they were under pressure. I attached the tool, but the highest I was able to get the pressure to was 7psi, and that only momentarily. All pressure leaked out almost immediately. I heard hissing from many different locations in the cooling system, but because I wasn't able to maintain pressure I was unable to locate them.

There is a hose going from the passenger side valve cover to the air cleaner assembly, possibly a PCV hose. I had to disconnect that in order to remove the air cleaner assembly. Gases and pressure was coming from that hose, and I thought maybe I was losing pressure there having that hose open. I plugged up the hole with the end of a screwdriver and tried the test again, no difference.

As far as the dead cylinder thing, I don't think that's necessarily true in this case. I may get 17mpg, but that's not extraordinarily bad for the gas guzzling 4.3. If one or more cylinders were dead the mpg would be abysmal. The idle isn't always rough though, it comes and goes, like a periodic shutter or shiver.

Anyway, I've got everything but the air cleaner back on right now. I'm going to go back out, put that on, warm the engine up, and try the pressure test again. I'll letcha know how it goes.

 

Here's the video, check it out!

 

check your weep hole on the back of the water pump also...

 

This is indeed a sad post.
I may soon not meet the minimum qualifications to be a member here.
I took the Jimmy up to Meineke today to test the a/c (had a free inspection coupon) and to have them diagnose the leak.
They confirmed what I had suspected. Well, not confirmed, but said ''90% sure'' that it was an intake manifold leak after they performed a pressure test.

I drove my car there and nothing was out of the ordinary except the temperature fluctuated a bit, but was still within good range. After they checked it, the guy who checked it said that it was so bad that if at all possible I should not drive it. I didn't get past the first stop light before my engine stalled and made a huge plume of smoke.

I barely made it home with the car, it stalled around 4 or 5 times total and did not have enough power to get into 4th gear.

When I got home, I waited a bit and started dismantling some things. The entire intake so far, from the air filter to the throttle body (probably further, but I haven't gotten that far yet) is coated in a thick, brown mixture.

I'm wondering now if my engine is blown, if it's a head gasket, or if I should just do the intake and see if that solves all of it.

 

Hopefully it's not to late. If you pull the lower manifold off the engine you will see the gaskets, if they look destroyed then odds are good they were the problem. I had a problem with fluctuating temperature in my truck a couple years ago, not knowing that it was beacuse the engine was almost out of coolant. If the manifold gaskets don't look too bad then move on to the next area to check the head gaskets, and if you going to pull the engine apart pull the water pump off the engine and check for any obvious sign leaking. If you decide to keep the old water pump, throw it into a bucket of water so the seals don't dry out.

Also, if it is to late. You engine bearings may already be on their last legs. Change the oil after you do the work as step to get all the old water contaminated oil out of the engine and hopefully six monthes down the road your engine will be fine.

 

I got down to the lower intake manifold today. Check out the video. ALL my auto parts are coated in a brown mystery liquid.

 

At this point it wouldn't hurt to replace the head gaskets, not so much as for head gaskets might be the problem, but because your engine coolant passages in the block are caked up and probably blocked with all brown gunk and you'll want to clean that garbage out. For pulling off the heads all you'll need to do is remove the rocker arms and push rods. The valves and springs will stay, but don't lose the valve lash caps that are on the tips of the valve stems.

Let me what know year your truck is and I'll post the torque specs and torque procedure for you. You will need head gaskets, a calibrated torque wrench, and a torque angle gauge, and new set of head bolts. The head bolts are torque to yield so they are generally a one shot deal and will probably break in the block if you reuse the old ones. A new set should cost less than $20. After that flush out the radiator with water and change the engine oil when everything is done.

I have rebuilt engines, if have any questions just let me know.