BBQ Tick or another issue?

[serioussv3n]

Hi,
Unfortunately, I have had a really annoying engine noise for about half a year, which has meanwhile significantly spoiled the fun with the pony.

In this video you can hear the clacking / knocking


at idle:


On the car lift you can hear the noise on the rear left cylinder bank.
When I hold the speed or accelerate, I can hear that noise.
The frequency of the noise depends on the speed. But I can’t hear it by decelerate.
And I have a knock knock knock at idle.

But all this I can only hear when engine is warm. I can’t hear it on cold engine.
When the engine is still warm and start the engine after 5 minutes again, the noise come back within 1-2 but not immediately after starting.

The cylinders were endoscoped. Cylinder bores all look good. Spark plugs all look good too.

The connecting rod bearings have already been changed. I've attached a photo of the old ones
But this didn’t fixed it.

I had 5w-30 and changed back to 5w-20. But that didn’t fixed too.

Has anyone an idea? Lifters? Rollers? Or piston slap? But the cylinders looks fine.

best regards,
Sven

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[serioussv3n]

no idea?

 

[GT Pony]

How many miles are on the removed rod bearings? Did whoever replaced the rod bearings measure the bearing clearance (with Plastigage) of the new bearings?

The 2nd video doesn't sound that bad, and it does not sound like the BBQ tick. The first video definately has a knocking sound. What's it sound like if a slight load is put on the engine while the car is in gear?

 

[serioussv3n]

The old bearings had about 39000 miles.

When it’s on slight or mid load in gear it sounds like a rattle in frequency of the rpm. Best noticeable between 2000-4000rpm.

I put ceratec on the engine. The idle knocking is much quieter. But the rattle sound is still present

 

[serioussv3n]

No one has an idea?

 

[DrZed]

Friend, from having blown numerous engines, this sounds like rod knock.
If you look at this manual from Mahle on what normal bearing wear looks like, your old bearings do NOT look normal:

Page 7:
https://www.mahle-aftermarket.com/m...b-2-1114-engine-bearing-failures-brochure.pdf

I would suggest that replacing the rod bearings when you already had a problem (likely), and not addressing why will land you in the same situation again. If, it is rod knock, which is sounds like (and sounds severe).

The engine needs to come out measured (as the previous poster said) and also the main bearing clearance and check for any oil flow issues.

Right now you can drive the car for 1000 kms and then take an oil sample from blackstone to CONFIRM for sure if there is metal in the oil or not, which will tell you if it is rod knock for sure.

I don't trust many builders so I would put in a running used engine or buy a crate one. There is a full engine for $9000 CDN (ouch!) on car-part.com (scrap yard search), but it is sealed and factory and I would only be comfortable with that, provided the engine runs well.

I'm sorry you're in this mess man,

 

[NGOT8R]

Look for copper shavings in the oil too, as that would be confirmation of a spun bearing. While this photo was taken following a catastropic engine failure (#2 cam cover bushing) on my Harley Sportster, it‘s merely a visual reference. If you see any copper flakes similar to this it’s definitely rebuild time

.

 

[Condor1970]

Could just be the mechanically driven fuel pump. They tend to be noisy.

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