Knock in engine after 100K service

[[email protected]]

Hey guys, really need some help now.

I recently have finished my 100k service on my RB26 and have gone to set the timing to 20deg on the motor using the timing light.

Upon starting the car up i hear a knock, sounding very metallic maybe coming from the 2nd or 3rd cylinder. I quickly scrambled to check if i could see the timing marks on the crank pulley with the light and i could only see them if the CAS was turned clockwise all the way and the mark on the housing only lined up with the 7th mark on the pulley.

I tore the engine down again to inspect my cam and crank positions in regards to the reference marks and they were absolutely spot on.

The engine when setting up the timing marks on the cam and crank pulleys is at TDC of the compression stroke as the tip of the cam lobes face directly left and right respectively meaning the vales are shut.

I have an Apexi power FC and splitfire coilpacks if that means anything

 

[Ben C34]

Have you got spacers behind the cas seeing as you aren't running the cover?

[[email protected]]

I havn't ben, would it not matter as the CAS is a rotational sensor and doesnt read depth?

[Ben C34]

12 minutes ago, [email protected] said:

I havn't ben, would it not matter as the CAS is a rotational sensor and doesnt read depth?

The cas will bottom out without the spacers and make noise like what is in the video. 

[[email protected]]

Didn't work unfortunately.

[Ben C34]

1 hour ago, [email protected] said:

Didn't work unfortunately.

That sucks.....  It certainly looks like the marks are lined up correctly. You didn't turn the engine when the belt was off did you?

[[email protected]]

I didnt have the marks lined up when i removed the old belt so once it was removed, i had to turn the cam gears and crank to line up with their marks. In doing this i made sure that when lining up all the marks that the no.1 piston was at TDC of the compression stroke. Which is how it is all supposed to go together to my inderstanding.

Edited November 25, 2018 by [email protected]

[Ben C34]

5 hours ago, [email protected] said:

I didnt have the marks lined up when i removed the old belt so once it was removed, i had to turn the cam gears and crank to line up with their marks. In doing this i made sure that when lining up all the marks that the no.1 piston was at TDC of the compression stroke. Which is how it is all supposed to go together to my inderstanding.

I hope this isn't the reason for the noise  but what you explain is the opposite of what you should do if you need to turn the cams. You would set the pistons so they are all down from tdc and rotate the cams first, then bring 1 to tdc. This is to avoid hitting valves into pistons.

[BakemonoRicer]

Rebuild time

[GTSBoy]

It does sound like a head off investigation at the very least.  If you're lucky, it's only collected a few valves and the pistons are sound enough to leave alone.

[[email protected]]

Thanks for the replies ben, so What your saying would just avoid a valve hitting a piston when i turned the cams back without the belt, would that cause a significant enough clearance issue? I dont recall hearing anything ever hitting something else when doing the job but it could be possible now that youve said that.

Edited November 26, 2018 by [email protected]

[iruvyouskyrine]

What you should have done is put the old timing belt back on and kept winding the engine over via the crank bolt until all the timing marks lined up, then slipped old belt off and put new one on. (my preffered way that way you know 100% there will be no valves getting mashed)

Or do what ben said.

And i agree a noise that loud is not something that just appears without a decent mechanical fault. Remove head and inspect.

[[email protected]]

Yes at this point i have no idea what the timing was like before i took the belt off. No fix yet, i have taken the spark plugs out and stuck a camera down each cylinder, from what it looks like i may be getting some piston slap in cylinder 2 as there is a slight mark on the piston where the first intake valve is. How that would have occurred i have no clue and i also have no idea how to fix it.

[Dobz]

Comp test to find affected cylinders if it is a bent valve. It sounds a little like a lifter with too much clearance. Did you turn the crank with no belt and spark plugs still in?

[[email protected]]

Dobz, i did mate, only about a quarter of a turn to get it lined back up with the mark, i will be checking clearances when i get the chance this weekend.

  

[[email protected]]

So i ended up finding some other people who have had similar problems, I should add that the rocker covers were off for about a month and i had just covered the cams with cloth to keep shit from getting in there.

Both of the following posts are seen to be due to noise in the cover due to oil starvation in the head, but the question would be how can i safely get oil into the head without revving the shit out of it like the guys in the youtube video and risk the whole motor?

 https://www.gtr.co.uk/forum/366218-desperate-need-help-rb26-knock-not-bottom-end-video.html

 

Edited November 30, 2018 by [email protected]

[Robocop2310]

2 hours ago, [email protected] said:

So i ended up finding some other people who have had similar problems, I should add that the rocker covers were off for about a month and i had just covered the cams with cloth to keep shit from getting in there.

Both of the following posts are seen to be due to noise in the cover due to oil starvation in the head, but the question would be how can i safely get oil into the head without revving the shit out of it like the guys in the youtube video and risk the whole motor?

 https://www.gtr.co.uk/forum/366218-desperate-need-help-rb26-knock-not-bottom-end-video.html

 

Reminds me of this video...

Back to the topic, I think your coilpacks are stuffed.

[tridentt150v]

Interestingly...I did the water pump and belt kit etc on mine.  It was on front ramps in the driveway for a day or so while I did bits to it.  I also left it so that the sealant [for the water pump] had time to set.

Anyway, after a couple of days I finally finished and started it up and it was very noisy, turned off, left and tried again but still noisy.  So I turned it off, jacked it up and took the ramps out [can't drive off them due to the front bar anyway] then started it up again and it was fine.

Oil starvation, bearing load, dry water pump, whatever, no idea, don't know.  That was 10,000km ago, car is fine. 

[[email protected]]

5 hours ago, tridentt150v said:

Interestingly...I did the water pump and belt kit etc on mine.  It was on front ramps in the driveway for a day or so while I did bits to it.  I also left it so that the sealant [for the water pump] had time to set.

Anyway, after a couple of days I finally finished and started it up and it was very noisy, turned off, left and tried again but still noisy.  So I turned it off, jacked it up and took the ramps out [can't drive off them due to the front bar anyway] then started it up again and it was fine.

Oil starvation, bearing load, dry water pump, whatever, no idea, don't know.  That was 10,000km ago, car is fine. 

Any noise like what is in my original video?

[tridentt150v]

No, not like that....that's bad!!!