Tips on looking at carbon/oil build up on exhaust valve ports?

[aw614]

I'm beginning the process to remove my head (taking my time removing a few parts here and there) and I had a good look at the exhaust valve ports and have some noob questions about what I am seeing.

My cylinder 4 exhaust port looks like this

IMG_20220217_181738.jpg (2.71 MiB) Viewed 1110 times

IMG_20220217_181651.jpg (2.86 MiB) Viewed 1110 times

Cylinder's 1-3 exhaust ports for the most part look like this one cylinder.

IMG_20220217_181721.jpg (2.08 MiB) Viewed 1110 times

Cylinder 4 doesn't look good and looks like oil is on both valve stem. Could piston rings cause what I am seeing or is that going to be valve guide/seals? The spark plug was getting wet with oil and fouling quickly.

But on cylinders 1-3 is that normal or should it be cleaner that that?

When I pull the head out, am I going to notice any other signs of this on the cylinders? scoring cylinder walls and what about the top of the pistons? Carbon fouled? What else should I look for?

This is my first time with diagnosing this and hoping anyone with experience can chime in.

[aklackner]

I'm beginning the process to remove my head (taking my time removing a few parts here and there) and I had a good look at the exhaust valve ports and have some noob questions about what I am seeing.

My cylinder 4 exhaust port looks like this

IMG_20220217_181738.jpg

IMG_20220217_181651.jpg

Cylinder's 1-3 exhaust ports for the most part look like this one cylinder.

IMG_20220217_181721.jpg

Cylinder 4 doesn't look good and looks like oil is on both valve stem. Could piston rings cause what I am seeing or is that going to be valve guide/seals? The spark plug was getting wet with oil and fouling quickly.

But on cylinders 1-3 is that normal or should it be cleaner that that?

When I pull the head out, am I going to notice any other signs of this on the cylinders? scoring cylinder walls and what about the top of the pistons? Carbon fouled? What else should I look for?

This is my first time with diagnosing this and hoping anyone with experience can chime in.

What’s a compression test say?
If rings I’d think compression would be low in that cylinder. If compression is good or the same as other cylinders at least, then it’s not something on the cylinder side of the valve.

[aw614]

I'm beginning the process to remove my head (taking my time removing a few parts here and there) and I had a good look at the exhaust valve ports and have some noob questions about what I am seeing.

My cylinder 4 exhaust port looks like this
IMG_20220217_181738.jpg
IMG_20220217_181651.jpg

Cylinder's 1-3 exhaust ports for the most part look like this one cylinder.
IMG_20220217_181721.jpg

Cylinder 4 doesn't look good and looks like oil is on both valve stem. Could piston rings cause what I am seeing or is that going to be valve guide/seals? The spark plug was getting wet with oil and fouling quickly.

But on cylinders 1-3 is that normal or should it be cleaner that that?

When I pull the head out, am I going to notice any other signs of this on the cylinders? scoring cylinder walls and what about the top of the pistons? Carbon fouled? What else should I look for?

This is my first time with diagnosing this and hoping anyone with experience can chime in.

What’s a compression test say?
If rings I’d think compression would be low in that cylinder. If compression is good or the same as other cylinders at least, then it’s not something on the cylinder side of the valve.

I need to get it back from a friend as he hasn't returned it back

Could I do anything with a leak down tester? I have the header off the car and valve cover unbolted, that shouldn't impact results?

[aklackner]

I’d think leak down should provide pretty direct indication if rings are sealing or losing pressure worse in a cylinder.

[Sporky82]

Leakdown test for sure, its a much better method for determining what the health of the engine is.

Valve seals are a very common wear item on any Honda, especially if they have never been changed. But judging by those photos it could be the oil control rings have lost their tension.

[DC231]

I'm beginning the process to remove my head (taking my time removing a few parts here and there) and I had a good look at the exhaust valve ports and have some noob questions about what I am seeing.

My cylinder 4 exhaust port looks like this
IMG_20220217_181738.jpg
IMG_20220217_181651.jpg

Cylinder's 1-3 exhaust ports for the most part look like this one cylinder.
IMG_20220217_181721.jpg

Cylinder 4 doesn't look good and looks like oil is on both valve stem. Could piston rings cause what I am seeing or is that going to be valve guide/seals? The spark plug was getting wet with oil and fouling quickly.

But on cylinders 1-3 is that normal or should it be cleaner that that?

When I pull the head out, am I going to notice any other signs of this on the cylinders? scoring cylinder walls and what about the top of the pistons? Carbon fouled? What else should I look for?

This is my first time with diagnosing this and hoping anyone with experience can chime in.

Most of the times I've seen the exhaust port looking that bad it's been because of ring issues. I've personally never seen a bad valve seal cause that much oil leakage. Only seen light seepage residue on the valve and guide if it's valve seal related.

Apply air pressure to the cylinder with your leak down tester and I bet you hear air like crazy coming into the crankcase past the rings. You can listen for air coming through the intake manifold, exhaust, crankcase to pin point leaks in intake valves, exhaust valves, piston rings.

[aw614]

Most of the times I've seen the exhaust port looking that bad it's been because of ring issues. I've personally never seen a bad valve seal cause that much oil leakage. Only seen light seepage residue on the valve and guide if it's valve seal related.

Apply air pressure to the cylinder with your leak down tester and I bet you hear air like crazy coming into the crankcase past the rings. You can listen for air coming through the intake manifold, exhaust, crankcase to pin point leaks in intake valves, exhaust valves, piston rings.

I think you might be right its the rings. I just did a leakdown test, cylinders 1-3 all were within 90-95 psi out of 100 psi per my leakdown tester. It did feel like the exhaust valves with the header out was leaking a bit of air from cylinder 4. Might need to run it again to see from the breather and intake...

Cylinder 4, was 25-30 psi out of 100 psi so like 70% leakage

I don't think a valve guide or a valve seal could cause that much leakage can it? Cylinder 4 is the one that gets beat up the most due to heat and being further away correct?

[DC231]

Most of the times I've seen the exhaust port looking that bad it's been because of ring issues. I've personally never seen a bad valve seal cause that much oil leakage. Only seen light seepage residue on the valve and guide if it's valve seal related.

Apply air pressure to the cylinder with your leak down tester and I bet you hear air like crazy coming into the crankcase past the rings. You can listen for air coming through the intake manifold, exhaust, crankcase to pin point leaks in intake valves, exhaust valves, piston rings.

I think you might be right its the rings. I just did a leakdown test, cylinders 1-3 all were within 90-95 psi out of 100 psi per my leakdown tester. It did feel like the exhaust valves with the header out was leaking a bit of air from cylinder 4. Might need to run it again to see from the breather and intake...

Cylinder 4, was 25-30 psi out of 100 psi so like 70% leakage

I don't think a valve guide or a valve seal could cause that much leakage can it? Cylinder 4 is the one that gets beat up the most due to heat and being further away correct?

only way would be is if you have a burnt out valve. 4 is the furthest away from the oil pump so it can be more susceptible to oiling issues

[aw614]

only way would be is if you have a burnt out valve. 4 is the furthest away from the oil pump so it can be more susceptible to oiling issues

Welp took the head off today, and it doesn't look like the valves were burnt, but the valves and the pistons being carbon are caked black
Valves

IMG_20220312_154515.jpg (4.86 MiB) Viewed 915 times

Block, The wet oil on cylinder 4 I think was from the oil dripping from pulling the head

IMG_20220312_154537.jpg (5.36 MiB) Viewed 915 times

IMG_20220312_154623.jpg (5.26 MiB) Viewed 915 times

IMG_20220312_154629.jpg (3.79 MiB) Viewed 915 times

[DC231]

only way would be is if you have a burnt out valve. 4 is the furthest away from the oil pump so it can be more susceptible to oiling issues

Welp took the head off today, and it doesn't look like the valves were burnt, but the valves and the pistons being carbon are caked black
Valves
IMG_20220312_154515.jpg
Block, The wet oil on cylinder 4 I think was from the oil dripping from pulling the head
IMG_20220312_154537.jpg
IMG_20220312_154623.jpg
IMG_20220312_154629.jpg

At the Honda dealership they re-ring engines all the time without pulling the engine block or doing any machine work from oil consumption. The ring gaps all fall in line over time and cause oil consumption. If the cylinder walls look good they just pull the Pistons and install new rings. I've seen it done over a dozen times.