Bent Con Rod?

**AcidicDavey** · Wednesday 25th March 2015, 01:20

Hey folks,

This is my breaker, just curious, do we think this is a bent con rod?

The PCV system is blocked and it started making this noise a couple of days after a remap I'm told.

**Sweep** · Wednesday 25th March 2015, 07:04

Sounds more like top end to me?

**LeeT5** · Wednesday 25th March 2015, 07:55

If a rod was bent then surely it would misfire on that cylinder. Yours, from what I can hear, is not misfiring. There is definitely a metallic noise but as Sweep says, it's more top end.

Think you'll need to do a compression test to at least isolate the problem. It could also be a hydraulic lifter has gone solid or not filling with oil.

**merc85** · Wednesday 25th March 2015, 08:09

Originally Posted by Sweep

Sounds more like top end to me?

Strangely the rods do when they go, not Deep knocking sound.

**merc85** · Wednesday 25th March 2015, 08:10

Originally Posted by LeeT5

If a rod was bent then surely it would misfire on that cylinder. Yours, from what I can hear, is not misfiring. There is definitely a metallic noise but as Sweep says, it's more top end.

Think you'll need to do a compression test to at least isolate the problem. It could also be a hydraulic lifter has gone solid or not filling with oil.

2 850's one being AndysR didnt miss fire with there bent rods

**merc85** · Wednesday 25th March 2015, 08:11

Could be a lifter, worth a oil change n filter

**t5 pete** · Wednesday 25th March 2015, 08:28

Yes they don't miss fire with a bent con rod they do have a destintive noise that gets faster as the revs raise

**AcidicDavey** · Wednesday 25th March 2015, 22:21

The car went back to the tuners after the noise started, full service yet noise obviously persisted.

If you listen to the clip again yes there is a lot of what sounds like top end tapping but also under that there is a slightly deeper sound tapping noise, the recording has quite picked that up too well

Anyway, I don't have a crane and if anyone wants this bare engine they can have it for FREE if they come and remove it out the top as I still need to be able to roll the car around.

**AndysR** · Wednesday 25th March 2015, 23:02

Sounds rod like to me, as already said mine ran smoothly and perfectly when I bent a rod, you honestly wouldn't have known if you always drove the car with the windows up.

**Biff** · Wednesday 25th March 2015, 23:09

That's a bent rod if you ask me. Memories!
Mine sounded like the little end, had perfect compression & no miss fire. The rod was certainly bent.
Just for interest when people have bent rods which one went? Mine was number 5.

**jamesy12345** · Thursday 26th March 2015, 07:04

Originally Posted by Biff

That's a bent rod if you ask me. Memories!
Mine sounded like the little end, had perfect compression & no miss fire. The rod was certainly bent.
Just for interest when people have bent rods which one went? Mine was number 5.

I read somewhere that detonation is most likely to be furthest away from the water pump, within the hottest cylinder, so that makes sense

**Doingitsideways** · Thursday 26th March 2015, 10:26

I agree Dave. Sounds like a rod.
It sounds deep when the bonnet is down, so not being absorbed by the bonnet insulation = bottom end, but not a deep enough thud to be a thrown big end.

Ah, too much boost, not enough fuel...

Poor thing