Jump to content
The mkiv Supra Owners Club

Help, engine making knocking noise!


Stonkin
 Share

Recommended Posts

  • Replies 76
  • Created
  • Last Reply

Top Posters In This Topic

As Chris says, if the shells had gone you'd very likely lose enough oil pressure to bring on the oil light at idle.

 

It sounds just like a sticking valve to me. (When it releases and pops up to hit the cam) I've heard one that sounded just like that before. As you lift the engine speed, it tends to get less too. Have you had any work done around the top end recently?

 

Hope it's this and not the big end shells mate. Although, unfortunately, it doesn't sound like it. :(

Link to comment
Share on other sites

Well they werent the kind of replies i was hoping to see this morning :(

 

I'm gona go out in a mo and start it up and remove the oil cap whilst running it to see if the noise is any different. I'll also try the screw driver thing.

 

I'll put up another vid, doubt it will help, but you guys know more than me.

Link to comment
Share on other sites

i checked the oil again and it is exactly on the top marker.

 

on cold start i couldnt hear the noise for ages, possibly because of the higher revs. It was only after it had been running for at least 5 minutes that i slowly started to hear it. I tried the screw driver thing, surprising what you can hear, but it did not seen to amplify the knocking noise into my ear at all. I tried removing the oil cap and it didnt make a huge difference, only that the noise sounded, more hollow! It certainly seems to come from the front to middle of the engine but it cant be that near the top or surely the screw driver would have made it sound louder?

 

First vid was during cold start:

 

image

 

second vid was after at least 5 minutes whne the noise could be heard:

 

image

Link to comment
Share on other sites

Odd one.

 

TBH I thought I could hear a knock on your cold start vid - or maybe that was your exhaust note. Difficult to tell. The noise is certainly different once the engine is warm anyway.

 

Sounds a bit too heavy to be top end to me, but then again its too intermittent to be bottom end. Does the car make this noise when you are driving it (i.e when its under load?). If it does then it may point to a bottom end problem. As Chris has already said, if it does it only at idle when warm it may be a big end clearance opening up. It could also be an oil pressure problem, but if your light doesn't light then that's ruled out too...

 

It might be worth draining the oil as K14 suggested and puoring it through a large piece of tissue paper over a bucket to see if any bits of metal fall out. Then you could temporarily refill it with a slightly thicker oil than usual as a test to see if that quietens it down - if it does then that would point to bottom end. I guess you would have mentioned it by now but have you got an oil pressure gauge?

 

It doesn't take much of a crack in something to make a knock like that, but its so intermittent that like Chris I would suspect it isn't a major failure.

 

Fingers crossed for you dude!

Link to comment
Share on other sites

I've timed the knock, and its 5Hz which is half engine speed at 650rpm (10Hz)..... so it should be cam related (highly likely as you say its coming from the top of the engine). It may also be a crank based (i.e. big end bearing) problem as the frequency of one cylinder's firing is once every 2 revolutions.

Link to comment
Share on other sites

Then you could temporarily refill it with a slightly thicker oil than usual as a test to see if that quietens it down - if it does then that would point to bottom end.

 

I was going to suggest that too, some cheap 20W/50 from the local shop. Doesn't matter what quality it is, as hopefully it will only be in for 5 minutes...then throw it away ;)

Link to comment
Share on other sites

:) your a clever man ki4sup, cheers. No i havent got an oil pressure gauge guys. i havent driven the car since my journey home last night. I drove it home very slow for about 2 miles as i had a bloody screw hanging out the side of one of the rear tyres which i got in a petrol fourcourt as i went to fil it up. The tyre is still inflated fully but obviously i cant drive it till i get a new one. The garage where i get them is obviously closed to as its good friday :( So i will order one asap. But i could not hear the noise when driving last and even if i slightly rev the engine the noise cannot be heard. I didnt even notice the problem until i got home and opened the car door.
Link to comment
Share on other sites

Not yet mate, i'm still waiting to collect a tyre, should have been in yesterday. I cant get the car picked up until its fitted. Mark at Phoenix is waiting for it though.

 

He was a bit baffled by it all but has mentioned a few possibilties and doesnt think it will be a huge problem or the noise would always be there.

 

fingers crossed anyway

Link to comment
Share on other sites

  • 2 weeks later...

LOL, i think the dragon's ink has had a massive affect on me. The car has never been so filthy, its strange though looking at it in that pic you can tell its still shiny underneath, reminds me of some of the HDR photos ive seen on here. Maybe its just me :)

Link to comment
Share on other sites

yeah bit of a lame excuse that one eh Linda ;) He will be gleaming again before long. I'm getting impatient waiting to hear what it is now, must resist calling Mark :)

 

:taped:

 

they'l probably leave it til 4.45 before they look at it :rolleyes: Go on call, you know you want to!! :ecstatic: lol

Link to comment
Share on other sites

Just collected car from Mark. He could not find a single thing wrong with it. Didnt make the noise once. He checked quite a few things as well.

 

Feeling a bit worried about driving it but i've given it some stick over quite a few miles and its running lovely, very weird...

Link to comment
Share on other sites

HI Buddy. I had a simolar thing a little while back now? Noises from pully/cam area? Turned out to be Auxil belt tensioner?

If the noise comes back, take the belt of, and if the noise goes away, you know what it is? Replace the bearing, or new unit

Link to comment
Share on other sites

Cheers mate, will remember that :) It was a knocking noise from the right hand side cam cover. just about where you put oil in. Mark had the Aux belts off and checked all pulleys. Its all quite strange. But its running absolutely spot on, pulling like a train tonight :D

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.