• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

B20 intermittent clank/knock noise

hiperfauto said:
Yes, you can reuse the flywheel bolts.

It's unlikely that it jammed suddenly but you never know.

Are you using the IPD lifters that came in the big bore kit? I had one fail on me many years ago. The pushrod punched through the seat in the lifter. This was before they sold Isky lifters and I think the kit you bought is from that era.

I always grind the sides of the tang on the oil pump drive when using a reinforcing ring so that it slips in and out nice and easy.

You can adjust the end play by tapping the bushing in the block up or down. Just make sure you don't bugger up the hole. I had a drift made out of aluminum to prevent damage to the bushing.
Click to expand...

I was wondering about the lifter myself. I had meant to ask you if you remembered what the failure looked like, and if you were able to tell from just removing the valve cover. I couldn't tell if any pushrod had dropped, but there were no loose rockers.

I do have a fair amount of wiggle in the tube from the oil pump to the block but it's a lateral wiggle, not a vertical one where it could be coming out and going back in. I'm hoping to get a few hours in the garage this weekend so I can properly go through and check end play on the crank and cam, ensure that the timing gears haven't come loose some how, and check torque on the big end and the rod bearings, and then when all of that turns out to be normal have a good ol' cry.
 
Ok... Finally got to spend some time out in the garage and check some things out.

Crank Endplay: 0.0045 - 0.005"
Cam Endplay: 0.0025 - 0.003"

No damage to distributor gear / Filed it down for easy installation.
All 6 rear main seal housing bolts are still there
timing gears were undamaged
pushrods all checked, all still complete.
every bolt/nut inside and outside of the engine has been checked for torque, nothing was loose.
New b30 motor and trans mounts have been installed (old ones had maybe 3k miles on them)
took a look inside the pushrod hole to see if there was anything obvious on the lifters, there wasn't.

I'm really at a loss for what this could be. I spoke with Volvo George (who had recently helped me tune the carbs) and he mentioned that he had heard it once on the exhaust side of the car and thought "WTF is that!?"

All of this is starting to make me think the unused exhaust hanger was just clacking against the exhaust.

Any suggestions for other things to check?
 
Another option could be piston slap I suppose..

What would I check to see if there was evidence of a piston slapping the cylinder bore?
 
Last ditch attempt. On a 140 there is a bracket that attaches to the transmission and supports the exhaust system. They commonly crack. Depending on circumstances they may fail without the crack visibly separating which then facilitates banging when there is movement of the exhaust system relative to the transmission mounted bracket.

As to piston slap. Piston slap will be continuous, not intermittent; but, will typically be more noticeable when the engine is cold becoming less noticeable or inaudible as the aluminum piston heats up and expands. If the clearances are really excessive the noise won't go away as it warms up. Slap is caused by collapse / excessive clearance of the piston skirt. Check your pistons skirt taper and clearances to the cylinder walls. Does your big bore kit use forged pistons? Forged pistons typically have higher expansion rates than the stock cast pistons and require higher cold assembly clearances. Net effect is that they will rattle away when cold which should become less noticeable / disappear when hot.
 
Last edited:
142 guy said:
Last ditch attempt. On a 140 there is a bracket that attaches to the transmission and supports the exhaust system. They commonly crack. Depending on circumstances they may fail without the crack visibly separating which then facilitates banging when there is movement of the exhaust system relative to the transmission mounted bracket.

As to piston slap. Piston slap will be continuous, not intermittent; but, will typically be more noticeable when the engine is cold becoming less noticeable or inaudible as the aluminum piston heats up and expands. If the clearances are really excessive the noise won't go away as it warms up. Slap is caused by collapse / excessive clearance of the piston skirt. Check your pistons skirt taper and clearances to the cylinder walls. Does your big bore kit use forged pistons? Forged pistons typically have higher expansion rates than the stock cast pistons and require higher cold assembly clearances. Net effect is that they will rattle away when cold which should become less noticeable / disappear when hot.
Click to expand...


To your point about the bracket: This is what I'm starting to think it is. It wasn't being used to support the exhaust pipe but it was still attached to the transmission. That said, the last time I put the transmission (and bracket) in, I noted that it was closer to the exhaust pipe than I felt like it usually was.

As per the piston slap, I still have to check the bore to see if there are any witness marks that would indicate a slap... I'm really trying not to take the pistons and rods out.. but I will if I absolutely have to.
 
Last edited:
Didn't see the question about the pistons before, but those pistons are the IPD cast pistons, which I believe were made by MAHLE at the time.
 
Mahle never made cast 92mm pistons with a 22mm pin AFAIK. They did make forged 93mm pistons.

I was told by someone at IPD that they had the big bore 22mm pin pistons made in Japan. The old ad even says the pistons are their own.

1541.jpg
 
I have a set of those IPD 'Big Bore' kit pistons sitting out in the garage. Let me go look them over for markings.
 
One skirt says 'VP 9204', the other has this symbol:
IMG_20200323_120013_zpsxewfhgoc.jpg


This was the 6-bolt (22 mm wristpin) big bore piston.
 
Well there ya go! I have no idea where I got that MAHLE info from!

@Hiperfauto...how does one check the oil pump shaft endplay? Is it just the lash between the gears? the oil pump is/was a brand new HD oil pump from IPD, if that matters.
 
The endplay you set is between the gear and the aluminum distributor housing clamp. With the gear and housing installed and pump removed move the shaft up and down. There should be ~.005"-.010" end play.
 
So how much is TOO much?

Because I measured the pump drive endplay at 0.020 - 0.025"

Additionally, I noticed a bit of gouging (gouging even feels like too harsh a word) on all of the cylinder bores, on both sides of the bore.. pictures attached.

61EADBBE-217F-4DFF-A8CC-A3BBABF66627_670.JPG



4F186265-2A23-4BEE-9E84-5FE50BB04721_670.JPG
 
hiperfauto said:
The endplay you set is between the gear and the aluminum distributor housing clamp. With the gear and housing installed and pump removed move the shaft up and down. There should be ~.005"-.010" end play.
Click to expand...

Ian, if the enplay is higher than that, is there a way to take up the slack? Like via a copper washer or something?
 
I suppose you could use a stainless steel shim (copper is too soft) but I just tap the bushing up a little to reduce the endplay. Be careful, the bushing is also soft metal and can easily be damaged.
 
oemoilleaks said:
The bushing on the oil pump?
Click to expand...

The bushing in the block that the drive gear rides in. It has a flat thrust surface on top that the gear part rides on, and a bearing part that the top part of the gear shaft rides in. I think he's talking about pressing it up and down in the block.

My experience is ***FAR*** more limited, and I've never even paid any attention to that bushing. It would be my understanding that the oil pump would place that drive gear in a constant pull, not like the back and forth torque the camshaft (as a whole) can get at lower RPMs (cam lobes going past TDC can push it forward). So I don't *think* that would be a source of noise, but again, my experience base is very limited.
 
You must log in or register to reply here.
Back
Top