Jump to content
DevilsCry

Knocking sound

Recommended Posts

Knocking sound started today and seems to only happen when I touch the accelerator, rattling stops when I let go as you can hear in vid nr 2.

Vid nr 3 is another new feature that came with the knocking update with a bit of smoke coming from between the engine and manifold..

Any ideas?

Share this post


Link to post
Share on other sites
5 minutes ago, Kaltorak said:

So no odd noises when simply at idle? Does it still happen when you accelerate but not in gear?

Bit of knocking sounds for a second when the engine initially starts but then normal idling, don't believe there was any noise when accelerating in neutral whilst standing still..

Share this post


Link to post
Share on other sites

Are there few loud knocking noises when you suddenly floor accel (better heard at low speed, when not drowning in tire noise). If yes, then i'd check direct injector seals.

Share this post


Link to post
Share on other sites

It sounds a little metallic. Do you have an aftermarket manifold? It sounds almost like it could be the manifold making contact with the metal undertray when the engine is twisting slightly under load. I had something similar, a metallic rattle, after fitting an Ace header - it would rattle on the undertray, but only when accelerating through certain RPM ranges. I fixed it by taking off the under tray and applying some "percussive maintenance" (ie, i found the raised rib portion of the undertray that was making contact with the manifold and flattened it with a lump hammer. 

If that's the problem, fairly easy to diagnose - just take off the undertray (only  a few bolts holding it on) and go for a drive. 

Share this post


Link to post
Share on other sites

Manifold is stock unfortunately. I'll spend this weekend having a look at it and see if it is something as simple as tightening something.

If I can't find it I'll have to keep my baby on the drive and save up to take it to a garage in the (hopefully) near future

 

I have seen too many youtube videos with similar sounds and they all have different issues so who knows!

Share this post


Link to post
Share on other sites

I think it's gone. Tried to start it today and it is struggling very hard to get it running, smells of burning oil and looks like the crank is wobbling.. 

Share this post


Link to post
Share on other sites

Update on the matter: I now have my car back from Fensport, after they did an amazing job at fixing it(and upgrading)!

They looked at the above videos and I told them what was happening, so they advised it needs stripping and proper looking at to see what exactly is broken. They had a good second hand engine available that had done 45000 miles if I just wanted to do a quick swap and save some money - but I wanted to upgrade some parts and kept that as a fallback option.

So initially we got to the following items:

  • New genuine crankshaft
  • Genuine conrod and main bearings
  • ARP head studs
  • Cosworth headgaskets
  • Brian crower forged conrods
  • Kelford valve springs
  • All fluids for running in and final
  • 2x oil filters
  • Toyota genuine coolant
  • Oil system improvements to dramatically improve oil pressure
  • Fensport custom oil pickup pipe
  • Remap

We went down the route of forged rods only as Tom is running this on his GT86 and he is hitting 460bhp on his daily very comfortably, though the advice is to not go higher than 500bhp.

They removed the engine and got majority of it stripped down and find that it is worse than anticipated. The insides had nasty charred black coating and the oil smelled burned.
The bearing on cylinder 1 conrod had somehow welded itself to the other bearing causing heavy crankshaft damage. It looked like the engine has been running like this for quite a while like this and remnants of bearing material can be found throughout the engine. Piston oil scraper rings have been blocked by burned oil and carbon preventing it from reaching the sump.  They needed to strip and clean the engine considerably more than expected and also inspect the heads to see if there is more damage to the camshafts or carriers.

2.jpg.1b2b85f665a66f1de17119b82571c39c.jpg

IMG_20200727_172415.thumb.jpg.b8a2a98c17286be6a4610d12f52039a7.jpg

3.jpg.36d3224b8697e73d0092665e69ad7e4c.jpgIMG_20200727_172446.thumb.jpg.409e79f43d2aac5604a0ffe29e267196.jpgIMG_20200727_172459.thumb.jpg.7338ae3029021c4464c801f5c3072211.jpg

 

Next step was to actually see what was salvageable from the engine and what is not. Depending if the damage is beyond usability with stock pistons, we potentially have to look at getting a brand new shortblock from Toyota which would be cheaper and less time consuming.

Luckily the cylinder heads were decent apart from light scoring on the camshafts and journals, but that seems to be very common in these engines and is no cause for concern. Unfortunately the block and pistons are no good at all and can not be re-used. I could have gone for more forged internals but as I'm not planning to go beyond 500bhp I opted for the brand new short block. Whilst we were waiting for that to come in, they built the custom oil pickup ready for the new setup.

shortblock1.jpg.e9f0d8df821e37300cca923641851af3.jpgshortblock2.jpg.d1fc6f995ac204e1b066f23aeabcae79.jpgPickup_pipe.jpg.dbc1a53f2d7721196110625b2919b343.jpg

 

Once the shortblock came in it was quickly getting rebuild with the new interals. You can definitely see which part of the engine here is nice and shiny!

IMG_20200912_174349.jpg.8c481137be4318e2b9428acbe91d6741.jpg

8.jpg.019d857f10368ab043e17128643a8b7f.jpg

9.jpg.20a191ab68c18880d97785731d5fdc64.jpg

 

I've had her back for a week now and runs like an absolute dream, I am happy I went down this route and looking forward to many more miles and future upgrades with Fensport.

 

Big shoutout to the team at Fensport for the amount of updates and pictures I received during the process including invaluable amounts of information on parts/upgrades/issues etc. Not to mention the few saturdays they came in to work on it due to having more issues than expected.

Happy to say I will definitely going back to them for anything else.

Share this post


Link to post
Share on other sites

Any discussion around what triggered the original failure?

I know you've mentioned a failed bearing and oil pipes being blocked, but any ideas around what caused those failures?

Share this post


Link to post
Share on other sites

It might be also other way around, cause & effect wise, oil pipes being blocked, and due insufficient oiling failure of bearings :).
For example, if too rich used sealant pieces falling off and blocking oil passages, as some dealerships botched valve spring recall warranty work, which later on resulted in fsck-up of engine/bearings and such ..

Share this post


Link to post
Share on other sites

I'm glad your engine is back together. I suppose an unexpected failure is inevitable eventually at twice design power, even with posh rods. Let's hope you have smooth running!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×