Strange noise coming from engine suddenly

Hi All

So this morning just went to start my pride and joy and noticed with a small amount of revs this knocking new sound coming from the engine bay, anyone have a clue whats happened? Only just had a new oil pump, cam belt, all belts really, oil change, plugs, you name it. No engine warning lights came on, no signs at all?

I posted a youtube vid here:

I've had dozens of cars and the only thing that sounds like this in my experience is big ends etc but its not as loud as my memory serves, either that or a loose pulley or fan or something? Happens out of gear so not box related and only kicks in when revs are raised from standard by a couple of hundred at least. Maybe its constantly happening but just too quiet at lowest revs.

Help!

YouTube video does not work

Sorry here it is again

Have you checked the crank pully is fully tight? I had something similar once and it turned out to be a loose crank pully.

Would make sense as you have had a new oil pump etc.

Here is my issue I had 10 years ago with my first Supra - http://www.mkivsupra.net/vbb/showthread.php?144238-Oh-no-knocking-HELP-ME&highlight=crank

The videos of course do not work.

Have you checked the crank pully is fully tight? I had something similar once and it turned out to be a loose crank pully.

Would make sense as you have had a new oil pump etc.

 

Here is my issue I had 10 years ago with my first Supra - http://www.mkivsupra.net/vbb/showthread.php?144238-Oh-no-knocking-HELP-ME&highlight=crank

The videos of course do not work.

What fixed your problem in the end? Was reading the posts.

What fixed your problem in the end? Was reading the posts.

I had a precision engineer make a brand new woodruff key to fit the damaged slot on the crank (it was not that badly damaged but needed sorting). Once that was done, we installed a new crank pulley and crank pulley bolt, torqued it down to spec and it was perfect.

Cost me a fair whack though to have that key made.

I had a precision engineer make a brand new woodruff key to fit the damaged slot on the crank (it was not that badly damaged but needed sorting). Once that was done, we installed a new crank pulley and crank pulley bolt, torqued it down to spec and it was perfect.

Cost me a fair whack though to have that key made.

Thanks, better than a suspected engine rebuild though

Well I drove it (very very slowly) to the mechanic who is less than a mile away, he said 'well that doesnt sound fucking great' but he doesnt suspect crank pulley - the more I hear it the more it reminds me of the sound when my big ends were going on my Mk2 MR2 albeit a bit quieter. Oil is pumping fine so not that new pump. Are we talking a rebuild here and if so a couple of questions, any opportunities to do other jobs at a fraction of the cost and how much is a rebuild likely to set me back? When was the last time anyone had one?

I could have had similar performance for a fraction of the price by buying a Nissan 370. But then, I'd be sat in a Nissan 370.

You've not had much luck mate. Check all other aux pulleys too first. If the wobble/catch sometimes they can cause belt to fray, happened on mine a year back, so worth checking belt too.

Hopefully it's not the big end [emoji25]

Didnt you post about this recently. And i uploaded a video just for you to show its the crank pulley?

Take the aux belt off and run it? Will eliminate everything bar the engine itself, but it doesn't sound good.

Well I drove it (very very slowly) to the mechanic who is less than a mile away, he said 'well that doesnt sound $#@!ing great' but he doesnt suspect crank pulley - the more I hear it the more it reminds me of the sound when my big ends were going on my Mk2 MR2 albeit a bit quieter. Oil is pumping fine so not that new pump. Are we talking a rebuild here and if so a couple of questions, any opportunities to do other jobs at a fraction of the cost and how much is a rebuild likely to set me back? When was the last time anyone had one?

 

I could have had similar performance for a fraction of the price by buying a Nissan 370. But then, I'd be sat in a Nissan 370.

Most people that require a full rebuild, rebuild with higher spec components (forced upgrades), so cost wise it depends what you want to do while its apart (if it needs rebuilding of course).

Even if it is worse case you may not need an entire rebuild.

Remember you have a MKIV Supra.. a name which is identified as a benchmark Japanese car, I don't ever remember hearing a 300zx, 350 or 370z being referred to as benchmark car, just OK...

I'm not going beyond full bpu so will replace whatever is snafoo'd with stock parts. If its big end I guess thats full rebuild time? Anyone know with stock whatever's that is ballpark?

Speak to James at Performance @ Hart on 07751150442 and he'll be able to give you a price.

As mentioned above, remove fanbelt and run for no more than 30 seconds at a time.

Next check the tension of the cambelt, my tensioner broke and it made a similar noise.

check the viscus fan isn't hitting the shroud, this should be checked whilst the belt is on and please don't try to touch it whilst running.

What did your mechanic actually say?

After stating the obvious about it not sounding good he said the first thing he would do was determine oil pressures then go from there and if necessary take the top of the engine off nd go from there. The first thing he did was have a good look at those front pulleys but I guess he will do those tests. He looked after a Mark III from new apparently so he knows Supras but I guess we will have to see what he comes back with as an update

Please let us know the outcome. Hope it's not serious.

Your not having a good time of it fella, only just seen this, i know that this all started with the FMS but did you ever have very low oil level as a result, as otherwise a cant see it being big end or other bearings, since you trust your mechanic i wont ask did he fit the oil pump correctly or us too much silicone gasket

Anyway as already said have all the belts, pulleys etc been checked, and have the belt covers been fitted properly have seen similar on other cars where something is contacting the cover, i presume he never removed the cam covers?

I passed all this on as many are thinking pulleys he's going to check all of those with a fine tooth comb before 'going in'. When the FMS went I was on the bypass of my town and it took a three mile (slow) trip to get back to the mechanic. When he checked how much oil had gone though it was only a litre, is that enough to do whatever has happened should it be internal issues? The person who fitted the oil pump is a new mechanic I found and he knows a MkIII very well and you can see the oil pumping through the filler cap so I guess thats eliminated that somewhat. Whatever it is I will fix it, regardless, even if its a total rebuild, but lets hope its not quite that serious. Guess if I had a rebuild I could have new rings put on and make my compression improve though, every cloud has a tiny silver lining.

Loosing a liter depending if it was full to start should be fine and no danger of starving bearings of oil, the "can see oil pumping through filler cap" is rather worrying as looking for oil there is not going reveal anything other than you will always see oil in the top end unless its dry, certainly not a positive check of oil flow, did the oil pressure idiot light go out when he checked? yet another reason for fitting an oil pressure gauge.

The fact that the motor was not making odd noises before the mechanic fitted the oil pump would be a good reason alone that you should take it back to them for further investigation.

Yes he said the same checking the filler was just for a cursory glance to check top end lubrication. Oil light went out almost immediately when started too. He's since done oil pressure tests and all is fine but that's where we are. Might need an oil pressure gauge then but I wanted th limit my pillar to twin with boost and AFR. Guess I could drill out the clock Ive seen people do that and mine has no clock behind it anyway!

The fact that the motor was not making odd noises before the mechanic fitted the oil pump would be a good reason alone that you should take it back to them for further investigation.

I didn't want to state the obvious but absolutely right. This sounds like poor install if not something simple like pulleys.

Speak to James at Performance @ Hart on 07751150442 and he'll be able to give you a price.

 

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I would also second this, as Sheefa says speak to James he certainly knows his stuff, he did my valve stem seals on my NA and service my Supras.

I think he's actually an engine builder by trade before starting up Performance@Hart.