B20, on acceleration and a little on decel, there is a squeal that sounds like a slipping fan belt. I've tightened the belt with no change,
then I removed the belt and the squeal is still there.
The noise seems to come from the front of the engine.
I previously had a problem with the cam retainer which somehow got bent and distorted. This created a lot of friction at the front of the cam.
Any suggestions before I do something radical?
Thanks for any input, suggestions, or real life stories.
Thanks,
-TR

I finally found it!
Eric had the right (as usual).
Somehow the crankshaft and the cover were not lined up correctly and were rubbing.

https://imgur.com/edxoqva
[img]https://i.imgur.com/edxoqva.jpg[/img]

I'm glad it isn't more serious than this.
I hope it's not an indicator of worn crankshaft bearings

Thanks for the help and advice form everyone.
-TR

Guy, did you F that up, or was it the way you got it?!?!

Why are you still using the old felt seal?

I posted a short video where you can clearly hear the squealing.

https://www.facebook.com/reel/1929067567491963

This thing is driving me nuts!
Is it possible I am spinning a crankshaft bearing?
If so, wouldn’t it be making noise all of the time?
Also I would expect a grinding or knocking noise.
I recently changed oil and fortunately haven't disposed of the oil filter. I'll pull it apart and check for any traces of metal. There weren't any on the magnetic plug, but brass isn't going to stick to a magnet.
There doesn't seem to be any drop in oil pressure (when cold) which is supposed
to be an indicator of a bad bearing. I'll put it back together and warm it
up and check again.

Thanks for any insight,
-TR

Hi TR,

Sorry you're having so much trouble there.

What oil are you running?

What car is that B20 in?

Bill

Bill

This is truly a pain, I was hoping to do more driving this summer.
I run Castrol 10-40 and add zinc treatment.
I just tore apart the oil filter and found nothing signiciant. Though there "seems" to be a little bit of a warm shine in the sediment.
The engine is a B20 in a 1958 Duett. Other than the noise, it runs great.

Thanks for your interest
-TR

I posted a short video where you can clearly hear the squealing.

https://www.facebook.com/reel/1929067567491963

Is it possible the seal hub on the front of the crankshaft is rubbing on the inside of the front timing cover?

The tolerances are very tight and Volvo made a special tool to center the front timing cover while the bolts are being tightened.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

Hi TR,

If you suspect some clogged oil galleries you can try adding some
some mystery oil to the crankcase. An old fashioned treatment for
rings and the guts of the engine. It wont hurt to give it a shot.

Are you using 10-40 Dino oil?
Full synthetic has a lot of advantages.
Mobil-1 tech support says that older Volvo engines benefit from
high zinc and that they have three options in their product line:
Mobil-1 Euro blends 5-40, 0-40 & Mobil-1 15-50.
(15-50 might be OK if you live in Death Valley)

I switched my newly acquired 940 from Dino oil to Mobil-1 euro blend
5-40 and needed to change at 1200 miles because the dipstick was so nasty.
Synthetic will clean up the mess left by dino oil.

I hope you can find your solution soon, good luck, Bill

Perhaps I've found the answer.
I pulled the timing gear and the cam retainer, the retainer had some wear and uneven scraping around the back side and a small spot on the front.
I installed a new cam retainer and spacer ring. While checking things over before reassembly I discovered that the spacer ring was below the surface of the retainer. I milled .0010" off the retainer and now there is a slight clearance for the timing gear.
The old spacer was .007" thicker than the retainer, but was still too thin.
How much should the spacer stand out from the retainer?
How much end play should there be for the cam?

I hope this is it, a squealing engine is no fun.
-TR

NOPE!
Got it back together and it still has the same problem.
Since it squeals with the fan belt removed that rules out the alternator and water pump bearings.
The squeal only happens on accel and a little bit on decel. It also happens when revving in neutral.
Is it possible it is the crankshaft thrust bearing?

Should I take the advice of HAL 9000 and return it to service until it fails?
-TR

Are you 100% sure the noise is coming from the front of the engine? I previously made the suggestion to spray around the crank seal and BB has repeated that. However if the noise is from the back you may have a rusty/damaged pilot bearing in the flywheel. If there is any fore and aft movement of the crank that could vary the noise.
EDIT: Does the squeal change at all when you depress the clutch pedal?

B20 crank end float 0.0018" to 0.0054" (0.47 - 0.137mm). There is no thrust washer.

I'll park myself at the engine bay and have my wife start it to be sure of the location.
Depressing the clutch made no difference.

The search goes on...
Thanks
-TR

Hi TR,

How about a noisy timing belt tensioner/idler ?

Bill

A B20 motor has a gear driven, in the block camshaft. All the OHC motors that followed used the basic architecture of the B18/B20 blocks. There is no timing belt tensioner. - Dave

Hi Dave,

Thanks for pointing that out, I'm a B20 newbie.
I was looking through a B20 FAQ here:
http://www.swedishbricks.net/faq/engb20.html
I got as far as the "Fiber Timing Gear" post, and someone mentioned "T-belt"
and I stopped reading and put up the post to TR. A goof it turned out.
They further mentioned that the fiber timing gear had a history of
service issues, can it squeal before failing?

Another question: Does the felt crank seal need to be oiled periodically?
They mentioned in that FAQ that the seal could dry out and leak.
Volvo changed to a neoprene crank seal at some point.

Bill

The fiber dear is bonded to a steel hub. When the bond fails it can create a knocking sound. The felt seals don't need to be oiled-running the motor gets enough oil to them to keep them wet. The seals (front and rear) can dry out if the motor isn't run in a long while. When they get dry they can shrink and then split. -- Dave

If you suspect the crank seal, see if you can get a drop of thin oil, perhaps Mystery oil on the shaft outside of the seal.

Bill

Thanks for the suggestion, but I have the old type (felt) seal and I have oiled it.
-TR

Spacer should be 0.1mm thicker than the spacer. See about 6:00 here.

https://www.youtube.com/watch?v=dpqJJpWzVPQ

Volvo Green Book apparently says "For the B20, the Volvo service manual specifies a permissible 'end float'(axial clearance) of 0.0008" - 0.0024"

After you fixed the cam retainer, how much end float does the cam have?

Hi TR,

Look in back of the crank pulley to see if something is wound around the crank.
I suppose a separated harmonic balancer wouldn't make a noise with no load.
Maybe a bad motor mount with metal to metal? Does the engine jump a lot when you gun the gas.

Hopefully you'll find the answer is something easy to repair.

Bill

Good ideas, but the B20 doesn't have a harmonic balancer.
I do have tight clearances but no contact (this is a B20 in a '58 Duett)

Replace the belt, the edges are worn and there is no grip on the pulleys

Thanks for the reply, but as I stated in my post it makes the same noise when the belt is removed.

Sometimes the updated front crankshaft rubber lip seals squeal until they're worn in.
--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

A couple squirts of silicone spray behind the pulley might indicate if that is the problem. An engine stethoscope or the traditional wooden dowel in the ear to the timing cover might show up any noises inside. I've a feeling you will be taking that cover off anyway.