2G HORRIBLE knocking when engine warms up

[edmaxx]

today i worked on my talon i have been rebuilding for the past couple months, fixed my boost leaks. i have a CAS sensor to eleminate my crank and cam position sensors, when i got it running pretty good (still looking for leaks) it had no knocking noise, pulled my spark plugs to see if they were getting gas, they were, put it back together.... started it up and clack! clack! clack! sounds like its coming from the bottom end.

any ideas?

 

[Absit]

Evo or 2G pistons on 1G rods are a nice cheap upgrade if you're planning on making enough power to care.

 

[etay89]

2g pistons, 1g rods

edit: dang...beat to the punch

btw, how is the head on it?

 

[edmaxx]

so i was looking around on craigslist and found a 100mm stroker crank? dont know anything about this, will it work and be beter?

ya im gonna hit the junkyard for some 1g rods!

 

[hubz91talontsi]

If you get that 100mm crank you will need to get pistons with the wrist pin offset 6mm or rods 6mm longer.

 

[edmaxx]

dang, thanks for the help, ill just get my crank done again. where would be the best place on the net to get 1g rods i can use on a 7 bolt crank.

i still dont know why my rod bearings failed on me, i had everything machined

 

[Tanro]

Don't bother with 1g rods...

Just run Evo 8/9 Rods and pistons unless you have allready swapped to a sixbolt....

 

[edmaxx]

alright, i have an bored out block and the evo rods, and bigger pistons im pretty sure.

 

[edmaxx]

So I thought the knocking coming from my engine was rod knock, so I pulled my engine today, only to find there is no metal in the pan, the bearings look great, and the piston rods are not moving at all from the crank.

It only happens when my spark plugs are on 1,2, and 4, when I put one in there is no noise (this is just cold cranking). When the engine is running it makes the same horrible noise, and gets louder the higher the rpm's.

Help. Please. The engine is out of the car.

 

[leecastillo]

are you sure its not a rod bearing

 

[edmaxx]

ya I pulled them all and they're fine, I dont know why it started doing this.

 

[BrokenTsi]

Sounds like rod knock to me.

 

[edmaxx]

Well, I don't know why they would be knocking if the bearings are perfectly fine? theres gotta be something else that could cause this

 

[BrokenTsi]

Have you pulled the bearings? How do you know they are fine? ive seen a rod knock and not leave anything in the oil pan before.

 

[edmaxx]

No I pulled the bearings and pistons, they look fine, normal wear on them. No movement or anything on the crank and rods?

 

[BrokenTsi]

Oh ok, weird.

Check the lifters? One can be stuck or collapsed.

 

[edmaxx]

Alright will do, ill get back on in a little to tell you what i see.

 

[dsmd1]

Well I can safely say you are not crazy! I had the exact same thing happen to me. Car started knocking, I knew it was rod knock. My mechanic friend confirmed it was rod knock. However, today I took apart the engine completely and my crank is in good shape and all the bearings in the bottom end have no play in them at all. What else could it be!?

 

[BrokenTsi]

Well I can safely say you are not crazy! I had the exact same thing happen to me. Car started knocking, I knew it was rod knock. My mechanic friend confirmed it was rod knock. However, today I took apart the engine completely and my crank is in good shape and all the bearings in the bottom end have no play in them at all. What else could it be!?

A separated crankshaft pulley can make a knock-like sound. This happened to my buddy's 98 GSX with 25k miles on it. I could have sworn it was the hydraulic tensioner. The crankshaft pulley looked fine at first until I messed around with it some more, then all of a sudden it separated into 2 pieces.

 

[donniekak]

Possible piston pin?

 

[dsmd1]

Hmm, I'll have to take a look at my crankshaft pulley. There is definitely nothing wrong with the bottom end of the engine. Piston pins all look good so its not that.. I'm building a 6 bolt to replace it with so I'm not too worried. I just hope it wasn't coming from the tranny or something. Anyone ever heard of non-engine related components making a rod-like knock?

 

[dsmd1]

Broken Tsi got it!

In case anyone comes across this thread in the future the knocking in my car was caused by a completely separated crankshaft pulley. If you look at the frame of my car you can see where the piece was clunking against it. I wish it hadn't been -40 out when this happened or I probably would have taken a closer look at the engine before tearing it down!

Again, thanks to everyone for the replys.

 

[BrokenTsi]

Good job!

Glad to hear it was an easy fix.

 

[XiKeiyaZI]

He tore his engine apart to come to the conclusion it was a pulley - 4 12mm bolts and a new pulley. Doesn't sound like an easy fix to me.

Sorry for your loss.

 

[BrokenTsi]

I forgot that he pulled the engine. Yeah, that sucks, but I guess its better than paying for a new engine or rebuild....to say the least.

 

[XiKeiyaZI]

I forgot that he pulled the engine. Yeah, that sucks, but I guess its better than paying for a new engine or rebuild....to say the least.

Oh yes - Glad it was something simple... but not so much for the expense lost over such a menial thing.

Proper Upkeep and inspection people, proper upkeep and inspection.