tap tap tap

[Azar]

Azar,
As the engine warms, the valve train should get tighter (quieter), if anything. Since you have low oil pressure at idle (confirm with external gauge), I would suspect that the oil is getting thinner as it warms, reducing the oil pressure even more... Sounds like the upper half of the engine could be starving for oil because of components in the lower half is worn (crank/bearings/pump/etc).

Thanks Ron! I will be investigating the pump. First I will change the oil to 10W -40.

Gesendet von meinem Mi 9T mit Tapatalk

[Ron]

i have a question too. if you change the cam, do you need to have the rockers machined to match?

A new cam will wear more during the first few minutes of its break in period than the rest of its life. The rockers (or lifters) must have a fresh mating surface. Otherwise, the cam WILL eventually fail prematurely and you will void its warranty.

FWIW- Once a cam has been broke in, the rocker (or lifter) it was broken in with must stay with it or be replaced with a new one.

According to the manual, the rockers can not be resurfaced.

These 'rules' are not picky, but critical...

[Azar]

Azar,
As the engine warms, the valve train should get tighter (quieter), if anything. Since you have low oil pressure at idle (confirm with external gauge), I would suspect that the oil is getting thinner as it warms, reducing the oil pressure even more... Sounds like the upper half of the engine could be starving for oil because of components in the lower half is worn (crank/bearings/pump/etc).

Hi Ron, it turned out to be valve clearance in the right bank. now it is silent again. But the question about the low oil pressure remains. When the engine is very hot (180-200), which is only after driving for 30 minutes at the +19C, the oil pressure light started to light up at idle (was replaced recently). Will do the oil change and report.

[David T]

Verify oil pressure with an accurate mechanical gauge. The wire going to the oil light is known to get burnt up and short to ground where it passes alongside the motor. Can make the light flicker and light up. Put a firesleeve on the wire. The wrong oil or not enough or a very dirty filter can cause low oil pressure.

[Ron]

Hi Ron, it turned out to be valve clearance in the right bank. now it is silent again. But the question about the low oil pressure remains. When the engine is very hot (180-200), which is only after driving for 30 minutes at the +19C, the oil pressure light started to light up at idle (was replaced recently). Will do the oil change and report.

Without more history, it sounds like the right side may have been too cool when the valve lash was set. It must be done when the engine is at normal operating temp ( 180°F +). Sometimes (especially with aluminum heads/blocks) you have to do one side and then warm it back up before doing the other.) Note that "180-200" is normal and shouldn't take 30 minutes to get there, driving or idling. (A good thermostat will force this.) This has me wondering if your gauge(s) are off and the oil is getting too hot, causing the oil to get too thin...

What is the gauge doing during all this? The light's wire shouldn't affect it. But, I agree with David, get a mechanical pressure gauge. And a way to accurately measure the coolant temp also.
Laser thermometers are <$20. Another type, placed in the hose immediately downstream from the thermostat, is hands free and gives you a more accurate reading of the coolant itself...
Record the pressure and temp when dead cold (sat over night), every 30 seconds as it warms up and at the highest temp it gets. Record the temp when the fans come on. Do the tests with new oil & filter, no additives. If no other red flags here, you are probably looking at worn parts (engine/cam bearings, pump), restricted pickup screen, or internal leak.

Did you inspect the rockers and cam lobes as Dave S suggested earlier in the thread when re-adjusting the right side?

[Azar]

Without more history, it sounds like the right side may have been too cool when the valve lash was set. It must be done when the engine is at normal operating temp ( 180°F +). Sometimes (especially with aluminum heads/blocks) you have to do one side and then warm it back up before doing the other.) Note that "180-200" is normal and shouldn't take 30 minutes to get there, driving or idling. (A good thermostat will force this.) This has me wondering if your gauge(s) are off and the oil is getting too hot, causing the oil to get too thin...

What is the gauge doing during all this? The light's wire shouldn't affect it. But, I agree with David, get a mechanical pressure gauge. And a way to accurately measure the coolant temp also.
Laser thermometers are <$20. Another type, placed in the hose immediately downstream from the thermostat, is hands free and gives you a more accurate reading of the coolant itself...
Record the pressure and temp when dead cold (sat over night), every 30 seconds as it warms up and at the highest temp it gets. Record the temp when the fans come on. Do the tests with new oil & filter, no additives. If no other red flags here, you are probably looking at worn parts (engine/cam bearings, pump), restricted pickup screen, or internal leak.

Did you inspect the rockers and cam lobes as Dave S suggested earlier in the thread when re-adjusting the right side?

Thanks Ron, I will try to answer step by step
- I did the valve adjustment when cold, so 0,1mm intake and 0,25mm exhaust, as per manual. the previous clearance was greater.
- perhaps my thermostat is always open. but it was 25 minutes ride and we were still at 170F. The fans kicked in after 30 minutes and standing at 200F and reduced the temp to 160F before switching off
- Ordered mechanical pressure gauge, arrives today or tomorrow. Can I measure it on the drivers side, there the oil pressure light switch is? or only on the passenger side where the sensor for the gauge is? I need a crushable washer, which I don;t have now...
- I have an infrared Thermometer, will try to measure the hoses. but you are right, probably not accurate? I think I remember the hoses being hot after the engine start, means perhaps my thermostat is stuck open. had this on my BMWs
- Restricted Pickup Screen and Oil pump - can I inspect them by just dropping the oil pan? I presume I need a new oil pan gasket then.

- I did unscrew one rocker (I hope I got it right? the rocker is the screw which I adjust?) but forgot to make a picture. I am not an expert but there was a slight wear pattern on them like on the hammer. I did make the photos of the cam lobes - attached.

https://photos.app.goo.gl/mR9XKJGzYGBAPXq18 - here are also the videos before and after the valve adjustment.

Many thanks for your support!

[Azar]

Verify oil pressure with an accurate mechanical gauge. The wire going to the oil light is known to get burnt up and short to ground where it passes alongside the motor. Can make the light flicker and light up. Put a firesleeve on the wire. The wrong oil or not enough or a very dirty filter can cause low oil pressure.

Thanks Dave, will do! Appreciate your help!
I was under the car and the oil pressure gauge sender on the passenger side is not easy to remove. Can I measure it on the otherwise instead?

Gesendet von meinem Mi 9T mit Tapatalk

[Ron]

Thanks Ron, I will try to answer step by step
- I did the valve adjustment when cold, so 0,1mm intake and 0,25mm exhaust, as per manual. the previous clearance was greater.
- perhaps my thermostat is always open. but it was 25 minutes ride and we were still at 170F. The fans kicked in after 30 minutes and standing at 200F and reduced the temp to 160F before switching off
- Ordered mechanical pressure gauge, arrives today or tomorrow. Can I measure it on the drivers side, there the oil pressure light switch is? or only on the passenger side where the sensor for the gauge is? I need a crushable washer, which I don;t have now...
- I have an infrared Thermometer, will try to measure the hoses. but you are right, probably not accurate? I think I remember the hoses being hot after the engine start, means perhaps my thermostat is stuck open. had this on my BMWs
- Restricted Pickup Screen and Oil pump - can I inspect them by just dropping the oil pan? I presume I need a new oil pan gasket then.

- I did unscrew one rocker (I hope I got it right? the rocker is the screw which I adjust?) but forgot to make a picture. I am not an expert but there was a slight wear pattern on them like on the hammer. I did make the photos of the cam lobes - attached.

https://photos.app.goo.gl/mR9XKJGzYGBAPXq18 - here are also the videos before and after the valve adjustment.

Many thanks for your support!

Seems you have the valve clearances correct. Just in case:
Valve Clearance.jpg
This is from the Volvo Service Manual, Pg. 59.
But, follow the spec sheet if an aftermarket cam.

Sounds like thermostat needs attention to me.

Rule of thumb is check oil pressure at the place furthest from the oil pump. But either place should be OK, assuming the gauge reads low too...?

Infrared units are very accurate. The problem is reaction time and hitting the correct spot, I.E., you can shoot the thermostat housing and the attaching bolts an inch away and get 3 different readings, and, the metals take time to heat/cool, at different rates. Keep this in mind and I'd say you can use one here, since the temps are so far off.

You can see the screen with the pan off, or a bore-scope...
Looks pretty clean under the valve covers, FWIW.

Yes, the screw you adjust is on one side of the rocker/follower. The other side mates to the cam. Compare the wear to ones that didn't need adjusting.
What seems to be #3 intake (single lobe in pic) appears a bit worn. It's hard to tell...maybe only scuff marks from trash etc. Did you happen to see if you could feel the edge of the wear with a fingernail. If you can feel it, it's time to replace it before it breaks down and the loose metal trashes the rest of the engine. The mating surface is harder, so once it starts, it breaks down very fast.

[Azar]

Thanks Ron! I will do the tests. I noticed that I have an oil leak under the engine. Not sure where it is coming from. The Valve covers are dry. Mostly it is wet near the right motor mount and the lower part of the generator. The sensors and oil filter are dry. Can this be the reason for the low oil pressure?

Gesendet von meinem Mi 9T mit Tapatalk

[Ron]

YW!

It doesn't look like the leak would cause low oil pressure, unless it lost so much that the level got very low and damaged the bearings/etc.
If you are sure it isn't the valve cover, check: the cam plate on the end of the head, the oil gauge sending unit, and the starter's port (rear seal leak?). Chase the stains from front to back/to the highest point.