I have seen a number of people on this forum with the same problem that say I just don't see a leak. Then bam wow I see it and it was in front of their face all the time.

I suggest look harder longer crawl under the hot running engine and look bring a super bright flashlight.

Look very closely at the fill spout they crack all the time very common. What about the heater hose's where they inter the cab that can be a hard one to see. Do you smell coolant in the cab a heater core leak they can be very small but do leave a smell?

 

I dunno, DAKAZ. I've dealt with coolant issues on many cars but these trucks seem hard to troubleshoot.

I had a pressure tester on mine for weeks, pressure testing daily. Pressure tests are good. Tuck was on ramps and I spent a lot of time underneath it. I purposely exceeded the pressure beyond is stated on the cap, to the point where I was even able to create a small leak where it wouldn't have leaked normally. I fixed that and also changed cap twice, along with new filler neck.

I can't say the truck is losing coolant, but each time I open the cap, the fluid is not right up to the filler neck, like it should be. I can see the coolant down below though. It seems to be going to the overflow and not fully sucking back in when it cools. I've checked the hose from neck to overflow and it's airtight with no blockage. Even cut .5 inch off either end for a fresh seal. I'm living with it for now because I'm not really losing coolant, but it doesn't give the the warm and fuzzy.

 

Something to look into is maybe the overflow tank has a crack in it fill it up let sit a day if you can then check to see if it dropped any.


After my conversion I noticed every time I pull the rad cap its never full to the top like my old rad setup I think thats just how it works with the 2000 and up rad setups as I never lose any coolant but the overflow tank level fluctuates. I have noticed the overflow tank sometimes overflows with a small lose I see the coolant on top of my custom tank cap it has a breather hole easy to notice. Why that happens I'm not sure probably need a larger tank my guess thats the only after market tank that would fit my location?

 

So it's been a few days. I did the pressure test and found that he gasket around my water pump was slowly dripping. I put a new pump on and thought I was in the clear. Well, I'm not even close to being in the clear! I am still going through the same amount of coolant now as I was before. I've also had a ticking sound recently and thought it was my alternator going out. Just for kicks I took the serpentine belt off to make sure the tick went away. Well, it didn't. It sounded as though the tick is probably a valve tap and it was coming from the driver's side head. I pulled the oil cap off and noticed a hint of the notorious milkiness of an oil/coolant mixture. I looked into the valve cover and observed more of it. Another side note: I have noticed recently that when I cold start the truck it takes longer than normal for the oil pressure to come up (and is also noisy until the pressure comes up). My thought is that the less viscous oil/coolant drains more readily to the pan and has to get repumped up whereas normally the oil sticks around in key places, making for smoother starts. Not sure if that theory holds water or not.
This leaves me wondering how the engine passed the block test and the oil in the pan is not milky.

 

Well, that bit of milky could just be due to winter condensation - most vehicles get it some in the winter (well, mine don't, but for instance, today I did over 300 miles ... almost all highway.)

When you replaced the gasket, did you use thread sealer on all the bolts? Several go into the water jacket, and if you didn't use thread sealer, they'll leak and you'll chase problems no end.

RwP

 

Ralph, I did not use sealer! What happens if it get into the water jacket? Would that cause fluid leakage? It seems to me that coolant goes in there anyway and it wouldn't matter if it leaks into there. (I know I'm showing my lack of knowledge with that comment!) I'm guessing it'll be obvious if I pull the valve cover and it has excessive water/coolant in there (more than an acceptable amount of condensation).

 

I pulled of both valve covers to see how extensive the milkiness was. I assume this is a bit more than condensation. It's pretty nasty! I only took a picture of one, but they're both the same. It makes me wonder why both are gunked up. Could there be a bigger problem than a bad head gasket? What are the chances of both being bad? I assume pretty slim. So why do both valve covers have gunk?

 

How long you drive your car plays a role in how much of the milkiness you get. If you do lots of short trips in cold weather you are going to see that much "snot."

There is a LOT of moisture inside an engine when it's running. You will see it in both sides. The colder spots, like the valve covers, are the last places to burn off the moisture.

 

No, the problem with no sealant is that it'll leak around the bolts in the front, not that it gets into the oil.

Again, a lot of vehicles will SHOW condensation in the oil filler during this time of year due to not getting hot enough to boil the normal condensate out completely. I'd do an oil change and get the oil analysed before I worried too much, at this time of year.

(When it's hitting 100F outside and you get that condensate, THEN you worry *grins* )

And *ahem* The water jacket is where the coolant is, yes. It's the jacket that carries the coolant (water and whatever else) around to cool the motor ...

RwP

 

Ok, it could leak out the front of the bolts. I hadn't considered that!
I called my mechanic to see if they could run any tests that I haven't been able to do. I told him the whole story and what I've tried. The question of where the coolant has gone still is unanswered. Keep in mind, it's not a small amount that I'm losing. A slight drip somewhere would not cause this amount. He said it sounds like a cracked head or block. If it was just a head gasket, it wouldn't have failed the block test. All that said, I think I may pull the heads and have them tested. If they're cracked, I'll get some new ones (any suggestions where to get them?) and if they're not, I'm going to assume the block is cracked and probably write the truck off. If I end up keeping it, does anyone know of a reliable reman engine supplier? I put a Jasper in an old S10 I had years ago and LOVED it. I just can't get one from that source again!