Smoke from oil fill, losing coolant...

[DennisG01]

Bear with me as I get to the question - just want to provide as much info as possible...

I've always had a little tiny coolant leak (from some bolt on the back side of the port-side head?) since the engine was rebuilt (about 53K on the rebuild). No big deal as it would take 5K miles (give or take) to get to the point where the low coolant light came on. But recently the rate of loss has sped up. I initially thought it was just an air bubble as I had to refill again after less than 50 miles. But I just had to refill again after the same, less than 50 miles.

It is NOT showing up on the driveway (like that pesky little leak would) and oil level has NOT increased. In fact, it's a little low - but the engine always seems to eat a little oil since the rebuild. Less than one quart over 3K miles. With 2K miles on the current oil change, I'm down about 1/2 to 3/4 quart. The oil looks the same color (black) as it always does. Again, oil level is NOT increasing.

It is not in the ATF - that looks nice and red.

So this brings us closer to my question. As I was refilling the coolant (cold engine - about 45* ambient) I decided to also open the bleeder screw. I happened to have the dipstick out (engine was running) and noticed that there were puffs of greyish smoke coming out the dipstick tube. I closed the bleeder and the puffs went away. Opened the bleeder and the puffs came back, closed the bleeder and they stopped, etc.

I went for a short trip (10 miles) and when I came home I removed (engine still running) the oil filler cap. There was a small amount of greyish (maybe whitish) smoke coming out of the filler neck. I put my palm over the filler neck for about 10 seconds and there was no oily residue or discoloration to my hand. And then I looked at the underside of the cap. I use orange Dexcool. The cap smelled slightly sweet and so did the smoke coming out of the filler neck.

I am immediately thinking head gasket (but I am not an expert on this matter, by any means), but am wondering if that is the only possible cause as this engine was built to handle 25+ PSI by Ron Schoolcraft (If I remember correctly, he used ARP studs, for example). There are no drivability issues and all gauges read normal. About 53K miles on the rebuild. I'm going to look around for a local oil analysis company (for time's sake).

Any and all thoughts are welcome! And... I won't be driving it until I at least figure out if the coolant is getting in the oil as I assume that's pretty bad for an engine. Here is a pic of the filler cap:

[DennisG01]

I drained about 3 ounces of oil from the pan into an old baby food jar. I then put one drop onto a business card. This picture is after it soaked in for about 2 hours. The oil that I drained into the jar seems of normal viscosity and smells only of oil. There is no sweet smell to it - perhaps I mistook the smell I smelled earlier?

[Robyn]

Get the oil tested for glycol first.


The loss of coolant is always spooky on these beasts.

The come and go of smoke from the crankcase/oil fill when the coolant air bleed is opened and closed is ominous for sure.

The lack of leaks on the ground makes it even more ominous.

NORMALLY, a coolant leak past a head gasket will also show pressure in the cooling system with the HARD top hose symptom and coolant being blown out over the pressure cap.


My next question is what year is the block and the casting number ????

If this is a factory 98 block from the Burb in your signature

Two very bad scenarios come to mind.
A cracked #8 cylinder near the top deck. 97 and later blocks were common.
These can cause coolant loss into the cylinder and leak into CC too.
The cracks will tend to seal upwhen the engine is hot.

A crack that started in the main web and has crawled up into the lower end of a cylinder allowing a slow coolant leak into the bottom end.

Get the oil checked, then let us know.

I hate to throw cold water on the camp fire, but this situation looks ugly at present.

Get more data and we can move from there.

Allow the rig to sit over night, yank the #8 glow plug, unhook the IP shut off Sol, stuff a clean paper towel up by the 8 hole and crank the engine.

See wassssssup, if there is red coolant on the towel there is trouble in paradise.


Robyn

[DennisG01]

Thanks, Robyn. I will see if there's a local place to get oil checked tomorrow. If not, I'll send it off to Blackstone.

Yes, it's the original engine (although I bought the truck in 2002 with about 55K on it). When Ron had the engine, I remember him talking about the cracks that you're talking about. He said everything looked fine - that was at almost 100K, am at 150K right now. He also beefed up the engine block with splayed main caps. I realize, though, that just because it looked fine then, doesn't mean it stays that way.

I see 'some' indication of coolant coming out of the overflow rubber hose and onto the inner fender well. Doesn't appear to be much, though. I stuffed a paper towel underneath and will check again (if I end up running the engine for a bit). But not until I know the oil is clean.

I've searched through some old posts, but can't get a clear idea of where to find the casting number and date?

[DennisG01]

Oh... the fuel shutoff solenoid - that's the tall, cylindrical piece on the backside of the pump, right?

[Robyn]

Yesssss
Tall thing on the RH side of the IP when looking in from the front of the rig. (Drivers side)

Just unplug it and she won't start while you crank it.

Getting at the 8 glow is a beotch, but you need to see if anything comes out of the hole after sitting overnight or a day or two.

Let us know what shakes.

Robyn

[DennisG01]

Getting at the 8 glow is a beotch,

I remember.... although I tried to forget...

[Robyn]

From under the rig.

Right hand

Reach up around the down pipe, and access is fairly easy.

This is why I added the rat hole in the inner fender on the Dahooooley

[DennisG01]

Cool - I'll give that a shot once the outside temp warms up a bit here. Worst case, I'll just pull the inner fender as that comes out pretty quick. Good idea on that quick-access hole, though! I'll have to put that one into the 'ol noodle for later reference!

I found a CAT store near me and dropped off the oil for analysis.

[phantom309]

Have you check to see if all the intake manifold bolts are nice and tight?

clutching a little here,...

As Robyn says,. any time a motor is ingesting antifreeze,.

its bad,..

[DennisG01]

Clutching, yeah - for sure.

I was able to get to almost all of the intake manifold bolts. Most were very tight - a few I was able to turn the nut about 1/16 to maybe 1/8 of a turn tighter.

Getting to #8, with your tip, was easy. Looks like I even remembered to put some antiseize on it! Came right out. My wife turned the engine over as I held a white paper towel against the hole. The only thing I saw on the towel was blackish/greyish in color and dry. No wet, no orange.

In poking around, I found a small wet spot on the inboard edge of valley of the engine - front, driver's side corner - right under the big coolant hose where it attaches to the t-stat housing. I used a q-tip to reach down there and soak some up. It didn't 'appear' to be orange in color (but then again, it's resting on old metal) and I couldn't tell if it tasted sweet or not. It was not thick, like oil, though. The hose 'appears' to be in good shape.

I also saw a tiny bead of coolant sitting between the head and the block, on the driver's side, back corner. But am not sure if it is leaking there, or just showing up there from another spot.

Once I get the oil analysis back (assuming it's clear), I'll start the engine and give a better look for leaks.

[DennisG01]

A local shop let me borrow their pressure tester - I'll use that tomorrow.

[Robyn]

NOT SEEING coolant on that #8 hole is a good thing.

These engines are not noted for any real issues with random coolant leaks.

The oil test will tell us a lot.

The thing that worries me is the vapor at the oil stick coming and going with opening and closing the coolant bleeder screw

That is definitely spooky.

Cracks in the #8 hole can start small and not leak into the engine for quite a while.

If you can air up the 8 hole with the piston at TDC, you can likely check for an internal leak.

Just lock the crank and pressure the cyl.


If nothing shows up, try adding some Cadillac tabs to the radiator in the top hose and let them circulate.

A small weep can add up.

Now, does that Burb have rear heat ???

Maybe a good looky peeky over the bottom of the rig might show a leak in a coolant line heading aft.

Rear heater core can leak and not draw a lot of attention right off.

Good luck

Missy

[DennisG01]

"Spooky" - that's a good way to put it! It's like somehow the oil system and cooling system are connected. I did notice that the relatively new CDR vlave (and gasket) are pretty dirtied up with a lot of oily grime on them and the starboard valve cover.

When I pump up the system with 15lbs, I'll definitely take a real good look everywhere - including the rear heat.

Can you explain more about "airing up the #8"? I have a little snake camera - would I use that to look into the glow plug hole? I shoulda left that pump solenoid unplugged, huh? It was a pain to get it plugged back together.

"Cadillac" tabs? Some kind of leak sealing tablets?

[Robyn]

Use a glow plug adapter to connect to shop air.

Just like doing a leak down test.

Caddy tabs, yessssssssss, leakum fixum
Better than bars leak.

If its a head gasket or ??? on the compression side, likely nothing will fix that sort of leak.

If the oil comes back good then the coolants gotta be going someplace.

I am still puzzled by the bleeder changing the vapor coming out the dip stick hole.

[DennisG01]

OK, so let me see if I get this straight...

-- Get #8 cylinder to TDC using snake camera (is there an easier way to do this?)
-- Find plug adapter and fill with air. My compressor will only go to about 130lbs. I assume that's plenty safe since this engine creates more PSI than that by itself? Or should I not even use that much?
-- Listen to where air is escaping... air intake, oil fill, exhaust, bubbles in coolant overflow or bleeder screw

Anything I'm missing or doing wrong?

Something like this? http://www.oreillyauto.com/site/c/de...1771&ppt=C0103

[Robyn]

EASY WAY

Bump engine over, or use bar until air is coming out glow hole (compression stroke)

Lock crank with bar.

Use adapter to get air to cyl

You will get some air past the rings normally

If 130 will show bubbles in coolant you have a serious leak, and the coolant would blow out quick with engine running.


I am still thinking about a remote leak, like the rear heater or lines.

[DennisG01]

It's funny you bring up the rear heater lines. I just pumped up the coolant system with the pressure tool. Went around looking for leaks. Didn't find any out back, but it didn't take more than about 30 seconds for some drips to start showing under the engine.

Found a good drip coming from both plastic T-connectors (where the coolant line splits to go to the front and rear core. It seems as though it's just that the clamps aren't tight enough. I'll get two new T's (brass) and use worm gear clamps and see what happens.

For what it's worth, I left the system pumped up for 30 minutes and it dropped barely 1lb in that time.

[phantom309]

pressurizing the coolant often doesn't show much,.
compression from a cylinder is much more concentrated and can sneak past a gasket in one direction,..

[Robyn]

-Hmmmmm

My bet is that you been losing the juice from the heater hoses.

Does not take long to drop out quite a bit when they drip and leave puddles.