Check your oil?

Not for level, but for milky froth....

To do the block test /combustion gas test properly I have to drop the coolant level a bit, right? I don’t want any coolant getting in the tester, just then air?

I would rent a radiator pressure gauge from your local auto parts store, AutoZone and some others rent them. You need to see if your coolant system can hold pressure, the gauge can test your radiator cap too. If your coolant system can't hold pressure you have a leak either internal or external.

Don't pump up pressure gauge too high, 13-15 psi probably enough.

Also as others said your engine may have a coolant air bleed fitting that must be removed when refilling coolant then replaced and tightened after coolant flows out.

quote:

Originally posted by thumperfbc:
To do the block test /combustion gas test properly I have to drop the coolant level a bit, right? I don’t want any coolant getting in the tester, just then air?

That would be correct.
I am assuming you are using something like this tester.

quote:

Originally posted by Patrick-SP2022:

quote:

Originally posted by thumperfbc:
To do the block test /combustion gas test properly I have to drop the coolant level a bit, right? I don’t want any coolant getting in the tester, just then air?

That would be correct.
I am assuming you are using something like this tester.

Yup. I picked it up today. Will probably give it a whirl on the morning when it’s cold.

I can do the pressure test later too. I’ll pick that up when I return the block tester.

Test it engine hot, idling, with the coolant cap off, it will be reading the gas in the bubbles you are seeing.

quote:

Originally posted by rizzle:
Test it engine hot, idling, with the coolant cap off, it will be reading the gas in the bubbles you are seeing.

Ran the test this morning, started with cold engine and the fluid never changed color. I ran the test a 2nd time with fresh fluid once the thermostat opened, no change in color.

The only qualification is that the test tube thing doesn’t fit great in the hole because the hole is under the cowl. I had to shove it in at any angle. I think it was sealed and not pulling in air from the engine bay. I ran it a third time with the tester in the overflow tank nozzle but that didn’t seem to work.

Checked the oil, it appeared entirely normal. No “milkyness” or frothing.

This message has been edited. Last edited by: thumperfbc,

Was it misfiring at the time? it reads combustion gas. If the cylinder is not firing it will not read correctly.

quote:

Originally posted by rizzle:
Was it misfiring at the time? it reads combustion gas. If the cylinder is not firing it will not read correctly.

No, code free and running smooth.

Out of options from me. Originally a cold misfire, has leak down on #3, bubbles in cooling system.
Originally recommended a borescope camera in #3 with the cooling system pressurized.
I suspect if you run it long enough the white smoke will start.
Hopefully other techs will chime in with other ideas.
Everything points to a blown gasket or crack in #3.

quote:

Originally posted by rizzle:
Out of options from me. Originally a cold misfire, has leak down on #3, bubbles in cooling system.
Originally recommended a borescope camera in #3 with the cooling system pressurized.
I suspect if you run it long enough the white smoke will start.
Hopefully other techs will chime in with other ideas.
Everything points to a blown gasket or crack in #3.

The bubbles may have subsided... I haven’t looked for that since a couple nights ago. Maybe it truly was some air in the system from after I dumped coolant in? The AC and temp have been good the last 2 days.

I’ll do the pressure test as well. Scoping cylinder three is possible, but not in the next day or two. For that I need my buddy again since the plenum has to come off.

Either way, it is on borrowed time with the results from the leakdown, unless the valve adjustment scenario is the problem.