Small End play on connecting rods?

[davkav]

Right I have an issue with my rod install at the moment.

I am seriously getting pissed off with this car now, I think Ill just pack it in and sell it.

Anyway, I recently had my Integrated Engineering Rods fitted with stock pistons, new rings and cylinders honed.

I collected the car from my mechanic and over the following week or two I put 1000 miles on it with 10w40 before changing the oil and filter. His instructions. I believe he did the break in for me.

So mid week I dropped the oil and filter and put in a new filter and 5w40. I started the car and after a minute or so a loud knocking noise produced itself.
This noise could have been there all along but was not audible with the heavier 10W oil.

After about 5-10 mins when the car get up to full operating temperature and then some, the noise fades out and is only slightly audible when you listen under the car.

I brought the car back down to my mechanic and he has just gotten in touch with me to say that it looks like there is a bit of play in the small ends of the rods.
Before I brought the car down there was never any knocking noise like this.

Has anyone ever experienced this? What could have caused this?

[AudiA4_20T]

The small end? It wouldn't matter if there was play there the piston and crank are fixed. Sounds like an odd issue though, maybe spun a bearing

[davkav]

The small end? It wouldn't matter if there was play there the piston and crank are fixed. Sounds like an odd issue though, maybe spun a bearing

Don't quite follow what you are saying Clint. The piston and crank are fixed via the rod but there could potentially be play between the small end and wrist pin, right?

As a side note I find it hard to believe that it is in fact the small end. I am thinking spun bearing or piston slap myself.

[AudiA4_20T]

Don't quite follow what you are saying Clint. The piston and crank are fixed via the rod but there could potentially be play between the small end and wrist pin, right?

As a side note I find it hard to believe that it is in fact the small end. I am thinking spun bearing or piston slap myself.

Yes but he would have noticed that when putting them in...

I agree with you and would normally say piston slap but they are stock pistons in a stock bore... Unless he honed it out too much?

[davkav]

Yes but he would have noticed that when putting them in...

I agree with you and would normally say piston slap but they are stock pistons in a stock bore... Unless he honed it out too much?

Exactly what I was thinking and what I have been thinking since the noise produced itself, that maybe he honed it out too much.
He is stripping the head off tomorrow and removing the rods and pistons for inspection so we will see then.

[diagnosticator]

The small end piston pin bushings must be fitted relatively tight compared to the other bearings. 0.0005" pin to bushing clearance is a loose fit. Any thing looser will be noisy, especially cold. Are the IE rods rifle drilled to feed pressurized oil to the small end bushings from the big end bearings? The fit of the pin in the piston is important aswell. New parts are typically sized for a ~ 0.0002" clearance fit for a full floating pin design.

[davkav]

No John there not drilled. I didn't think I'd need them drilled. If IE supply them without rifle drilling I figured they would do the job.

[M-Hood]

Are you sure you got the IE rods with the 19mm wrist pin and not the 20mm?

[davkav]

Good question! But surely after 2000 miles they would have crapped themselves?

[onceover]

Are you sure you got the IE rods with the 19mm wrist pin and not the 20mm?

Exactly what I was thinking. Surely a shop would notice something like that though, right?

[davkav]

Just checked the box to be sure. Says 19mm on it.
I'll ask the mechanic to check them tomorrow but I'd imagine it would be blatantly obvious by how loose they are before installation.

[daihashi]

This might sound stupid, but are you sure you're not hearing the lifters? I suppose it could be piston slap but I imagine he would've had to of gotten carried away with the hone to make that happen. What does the car sound like under WOT? Are your knock sensors being triggered? If it is piston slap I'd imagine it would get worse under acceleration and your knock sensors should also be going off and pulling timing.

[davkav]

This might sound stupid, but are you sure you're not hearing the lifters? I suppose it could be piston slap but I imagine he would've had to of gotten carried away with the hone to make that happen. What does the car sound like under WOT? Are your knock sensors being triggered? If it is piston slap I'd imagine it would get worse under acceleration and your knock sensors should also be going off and pulling timing.

This was my initial conclusion as well. I thought it was chain slap from my Cam Chain Tensioner so I swapped a known good Cam Chain Tensioner and lifters and the noise did not change at all. It was only upon closer inspection that I realised the noise was still present from under the car when the engine was hot. You can't really hear from up top once it has warmed up.

[davkav]

Update:

Just got a call from the mechanic. He has removed one of the pistons and rods and there is definitely play at the piston end of the rod. He says there looks to be some wear on the wrist pin. I am meeting him tomorrow with the old rods and we are going to see is there any play with the stock piston/rods.

What a f**cking nightmare!!

[AudiA4_20T]

Update:

Just got a call from the mechanic. He has removed one of the pistons and rods and there is definitely play at the piston end of the rod. He says there looks to be some wear on the wrist pin. I am meeting him tomorrow with the old rods and we are going to see is there any play with the stock piston/rods.

What a f**cking nightmare!!

and this is why I'm done building motors for awhile

[daihashi]

Update:

Just got a call from the mechanic. He has removed one of the pistons and rods and there is definitely play at the piston end of the rod. He says there looks to be some wear on the wrist pin. I am meeting him tomorrow with the old rods and we are going to see is there any play with the stock piston/rods.

What a f**cking nightmare!!

all I can say is ugh!!! Sorry man, I feel your pain. :(

[davkav]

and this is why I'm done building motors for awhile

2.7TT swap here I come!

all I can say is ugh!!! Sorry man, I feel your pain. :(

Yeah needless to say I am pissed. And I know no matter how much I battle this out its going to come from my pocket...

[daihashi]

2.7TT swap here I come!



Yeah needless to say I am pissed. And I know no matter how much I battle this out its going to come from my pocket...

unfortunately true.. could take the opportunity to stroke it out to a 2.0 and let a quality machine shop put the block back together for you. It would ensure everything is balanced and clearances are tight. I'm one of those "while you're in there you might as well do ......" type of guys. If you're forced to throw money at it might as well upgrade. :D

[boy412]

unfortunately true.. could take the opportunity to stroke it out to a 2.0 and let a quality machine shop put the block back together for you. It would ensure everything is balanced and clearances are tight. I'm one of those "while you're in there you might as well do ......" type of guys. If you're forced to throw money at it might as well upgrade. :D

Yep yep. That's exactly what I am doing with my motor. Good luck davkav...

[davkav]

unfortunately true.. could take the opportunity to stroke it out to a 2.0 and let a quality machine shop put the block back together for you. It would ensure everything is balanced and clearances are tight. I'm one of those "while you're in there you might as well do ......" type of guys. If you're forced to throw money at it might as well upgrade. :D

That was the plan originally. I even got myself a second bottom end to work on and swap in once stroked. BUT the price of machine work alone over here was astronomical so I decided to stick with the 1.8L. Once I see over 400chp I will be a happy camper.

[davkav]

So I met up with my mechanic tonight. All four rods and wrist pins have the same symptoms. What the cause is I don't know.

The IE rod and wrist pin has a good bit of play in it. So I got out my original rod and whilst there is not as much play in it there is still a slight bit.

Before stripping the block down for the rod upgrade there was no noise whatsoever from my bottom end so I would say both the IE rod and wrist pin have gotten damaged and that is why there is play when I put the pin into the original rod.

You can visually see some scoring in the wrist pin ( see pictures below )

Is there meant to be a channel cut into the small end for oil to flow similar to that of the original rods?

As it stands I am trying to get my hands on a second set of pistons and rings to see if the damage is actually on the pin or the IE rod. But from what I said above it seems both rod and pin have been scored.

I also don't think this was installation error as all four seem to have failed the same way.

Thoughts?

[A4natomical]

Maybe IE accidentally placed 20mm wristpin rods into a 19mm package?
Can you measure the I.D. of the rod?

[davkav]

My head is so melted that never even crossed my mind. Ill get my hands on some 20mm wrist pins and check it out.

[onceover]

Just use a caliper to check...

[davkav]

I asked the mechanic there, he said he tried a 20mm he had to hand and it didn't fit. So that rules that out.

[daihashi]

I asked the mechanic there, he said he tried a 20mm he had to hand and it didn't fit. So that rules that out.

yeah, you shouldn't be able to squeeze a 20mm in there unless someone enlarged the size of the wrist pin hole; or did some serious mashing but that would've probably ruined the sides/skirts of the pistons as well.

The hole shown is used to lubricate the wrist pins. I haven't built a 1.8t engine yet, but here's how it typically works (note, I'm lazy so I just copied/pasted/paraphrased excerpts... but this explanation falls in line with all motor's I've built before):

Each connecting rod journal on the crank has a drilled hole that connects to the crankshaft internal oil passage. Oil flows out of this drilled hole and lubricates the connecting rod bearing. From there, it can get to the wrist pin one of two ways. Most engines have a hole somewhere on the outer rim of the connecting rod "big end" and through the rod bearing positioned such that when the crank oil hole lines up with it, it will be aimed up at the cylinder and piston above. The wrist pin get's blasted with a shot of oil from here.

The oil pressure is fed from the oil pump into the block journals, which in turn feed the main and rod journal bearings.

Your pins look like they were a bit starved for oil. Have you checked your oil pressure? Maybe it's low and can't adequately lubricate or cool the wrist pins? What do the pistons, rings and cylinder walls themselves look like? Have you pulled the rod bearings also to make sure that they are positioned correctly and not reversed? This could be starving the cylinder of oil completely or partially.

If the 1.8t uses oil jets/squirters then this is still applicable, but in a different way.

I would check oil pressure, check bearings... basically check to makes sure that sufficient oil is making it's way from the crankcase into the cylinders, pistons and wrist pin (shouldn't need a channel in the pin itself.. it's supposed to be a tight fit but kind of float at the same time). That pin looks starved.

[daihashi]

last pic shown here shows the oil feed at the rod bearing end:

http://www.intengineering.com/integr...v-audi-vw.html

Probably different rods, but same concept.

[613B6]

I can't tell from the pic but do they have a taper end?

[daihashi]

I also don't think this was installation error as all four seem to have failed the same way.

I think this is installation error, but won't know for certain until the the bearings and crank end of the rods are inspected; and oil pressure checked but that's probably not possible since it's torn apart again.

[davkav]

last pic shown here shows the oil feed at the rod bearing end:

http://www.intengineering.com/integr...v-audi-vw.html

Probably different rods, but same concept.

Cheers for the info. I understand what the holes are for alright, my question related to the channel that is cut around the inner circumference of the stock rods which is not on the integrated engineering rods. Ill get a picture up later to show you what I am talking about.

We did an oil pressure test before stripping it down and all was within spec.
I checked out some other pics of IE rods and they are as they should be.

I didnt however get my rods rifle drilled. I figured if IE offer them without rifle drilling then it should be alright.

I have one of the IE rods at home so I will take pictures of the big end bearings etc and post them up.

I can't tell from the pic but do they have a taper end?

Ever so slightly, I will get a better picture this evening. What effect would this have if any?


On further inspection of the wrist pin it seems it is worn down in the centre section where the small end of the rod would be located.

[AudiA4_20T]

That wrist pin honestly doesn't look too bad. How did he isolate the problem to that area? There is no other spot that it could have been? Was the motor eating lots of oil?

[davkav]

He took off the sump and was checking the rods for play when he noticed the movment between the rod and piston.

Stripped off the head and sure enough the rod and wrist pin have play in them. There is actual scoring on the pin itself which although you can't see it too easily, you can feel it when you run your finger over it.


To say I am gutted that this has happened is an understatement. I know the repairs shouldn't come out of my pocket but how do you prove if the rod was defective or the rods where put in incorrectly?

I have to get my hands on another 19mm wrist pin to check if the IE rods are scored at all and if they are that means I need new rods.
New or second hand pistons are going to have to be bought as I doubt I will find wrist pins on there own.
And then top it all off with new rings, fluids and the labour.
Fun times for my empty bank balance....


What is the actual difference between the 19mm and 20mm IE rods. Are the rods exactly the same bar the brass sleeve is drilled out the extra mill. Or are the brass sleeve in the small ends the same thickness and the rods are drilled out to the relevant size and the brass sleeve inserted then.
If the brass sleeve is just drilled out the extra mill I wonder can I get that machined over here and get my hands on some second hand 20mm pistons.

I need to get in contact with IE as well to see what they think.

[AudiA4_20T]

Honestly just ask IE we would all be speculating. As for money coming out of pocket, you might get the rods switched for free but labor is $$$. At this point I hate to say it but you're right the 2.7T would have been cheaper. There are so many factors when building a motor it just becomes a black hole of money. I had to rebuild mine after the first time too, it sucked.

This is why I tell everyone to get a spare block (or even a whole motor) and build that. That way, you can get your stock motor back in there and figure out which direction to go.

Btw I know RAI actually had to machine out the wrist pins one time with IE Ross because they were too tight

[davkav]

Honestly just ask IE we would all be speculating. As for money coming out of pocket, you might get the rods switched for free but labor is $$$. At this point I hate to say it but you're right the 2.7T would have been cheaper. There are so many factors when building a motor it just becomes a black hole of money. I had to rebuild mine after the first time too, it sucked.

This is why I tell everyone to get a spare block (or even a whole motor) and build that. That way, you can get your stock motor back in there and figure out which direction to go.

Btw I know RAI actually had to machine out the wrist pins one time with IE Ross because they were too tight

Good to know Clint, thanks.

I am in the middle of writing an email to IE at the moment so we will see what they say.

[M-Hood]

last pic shown here shows the oil feed at the rod bearing end:

http://www.intengineering.com/integr...v-audi-vw.html

Probably different rods, but same concept.

It is called Rifle drilling and is an option that can be done to the standard IE H beam rods and is already included in the IE Tuscan rods. Pauter also offers it which they call EDM.


It is good to have on a daily driver that does see plenty of low rpm driving or sitting at idle, but isn't really needed for a car that spends plenty of time at high rpms. I have been running Pauter rods without the EDM since 2003, no issues at all even when the car was used as my every single day car up to 2006. Even without the rifle drilling(EDM) oil is still going to get to that end of the rod.

[daihashi]

You should be fine without rifle drilling I'd think. The natural sloshing that occurs should be enough to get oil up there. Were the pins a better fit before they were installed in the motor and broken in? Just curious if they always had play and the mechanic installed them anyway.

I agree with Clint. Call IE, they may be able to give some information that will help you figure out what happened and why.

[ricekikr]

What I don't get is why the mechanic would instantly think it's the small end. I've never ever heard anyone think knock = small end.

I however have seen shops use sand paper rolled on a piece of wood/metal rod roughly the size of the small end to enlarge the hole.

Maybe mechanic felt small end was too tight and enlarged hole too much? Just a theory not pointing fingers

Or it was too loose to begin with and he shouldn't have proceeded with the build.

Bottomline is you shouldn't lose anything other than time.

[MikeWire]

I would bet as a experienced mechanic, he knows what rod knock sounds like when it is coming from the bottom end. With my experience, it's a loud "thud" sound every time the rod is pushed up and down by the crank. The piston end of the rod would probably sound similar but would be less noticeable, and maybe may be confused with piston slap. Valetrain noises are usually twice the RPM speed of the motor.

Davkav, that scoring look to be caused by looks like oil starvation. Any possibility the crank bearings spun or weren't installed correctly?

[daihashi]

Davkav, that scoring look to be caused by looks like oil starvation. Any possibility the crank bearings spun or weren't installed correctly?

My initial thoughts as well. Some scoring and very slight bluing (could be my monitor) on the pin. The Rod also looks to have wear in the middle of the wrist pin hole as well.

Looks like the pin has been fairly dry while rotating in the assembly. What throws me off is that he said that all his pins look like that. Which in turn I start to think installation error and not spun bearing, but without having seen the motor being put together and taken apart; before and after, all i can do is speculate.

[A4natomical]

Honestly just ask IE we would all be speculating. As for money coming out of pocket, you might get the rods switched for free but labor is $$$. At this point I hate to say it but you're right the 2.7T would have been cheaper. There are so many factors when building a motor it just becomes a black hole of money. I had to rebuild mine after the first time too, it sucked.

This is why I tell everyone to get a spare block (or even a whole motor) and build that. That way, you can get your stock motor back in there and figure out which direction to go.

Btw I know RAI actually had to machine out the wrist pins one time with IE Ross because they were too tight

Luckily I haven't had to tear my motor apart after my 2L build. It's been reliable and strong ever since. Everything was done right the first time around. You just never would anticipate failure from a defective part. That's that last thing on your mind. I'm surprised to hear IE has quality control issues in your experience Clint. Maybe Dave is experiencing the same type of quality control issue, but with the contra of having the I.D. too large.