Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E30 (1982 - 1993)

E30 (1982 - 1993)
God's Chariot. The E30 was produced primarily from 1982 through 1991. The cabriolet was the one exception which was produced through 1993.

Reply
 
Thread Tools Display Modes
  #1  
Old 06-17-2013, 11:00 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
What Sound Should You Hear When Hand Turning Crank Shaft?

Might be too hard to address this question via text/message board, but here goes...

I have a 1990 325i couple (automatic) with an estimated 220K miles. I'm not the original owner and don't know the car's history beyond my time with it over the past two years.

I changed the timing belt and water pump shortly after purchase (amongst other things). Due to a recent overheating incident, I pulled it apart again to check the head and the cooling system, but I left the timing belt and tensioner on.

My question is: what sort of sound should I be hearing when I hand turn the engine from the crank shaft? I have the plugs removed and the valve cover off. The water pump is also off.

When I performed the timing belt change two years ago, I didn't take note of the sound when I rotate the crank shaft to get to TDC. But now, I'm not sure whether or not I'm hearing something funky. Hard to describe. Not a clanking, but a sort of roar, mostly coming from below or inside cylinders 4-6. That's at 1-2 rpm anyway. Not sure what it would sound like at 1000-2000 rpm.

I have drained the oil, if that matters.

I don't really want to reassemble everything with new gaskets and seals and fluids, only to find that on start attempt, I've got some major breakdown in the cylinders or with my head or block. On the other hand, I don't want to remove the head if I don't have to.

I'm just trying to find a reference point for what mechanical sound the E30 ought to be making when the engine is turned by hand. I was hoping I'd find an online "how-to" video of someone changing a timing belt or doing a valve adjustment that would capture the "normal" sound. What I might have to do is post a video with audio of what I'm getting and see if anyone recognizes if it's normal or not.

Though, if it takes more than a few days to get feedback, I'll probably have pulled the head anyway, but any insight (or is it "in-hearing") would be appreciated.
Reply With Quote
Advertisement
  #2  
Old 06-18-2013, 02:30 AM
Nick323's Avatar
Nick323 Nick323 is offline
Nick's Toys
Location: Windhoek, Namibia, Africa
 
Join Date: Jun 2012
Posts: 721
Mein Auto: 323i E30 2-door
95 % chance that i could diagnose the sound, if you let me hear it
I suppose that will go for a lot of others here
Lion escaped from the san Diego zoo recently
__________________
Don't take life too seriously; no one gets out alive !
1984 323 currently being resurrected from the ashes
Reply With Quote
  #3  
Old 06-18-2013, 08:47 AM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
Thanks. See if this works...

Reply With Quote
  #4  
Old 06-18-2013, 10:28 AM
hornhospital's Avatar
hornhospital hornhospital is offline
D'oh, You kids!
Location: In the Grumpy Chair
 
Join Date: Jan 2008
Posts: 14,322
Mein Auto: 1995 318is / 1993 325is
Good grief! NO, that's not normal at all. And I thought you said the water pump was off....but the timing belt is still turning as it has to, to keep the valves from hitting the pistons. If the water pump was off, the belt wouldn't drive the cam, since isn't it part of the belt tensioning circuit? The roar almost sounds like the belt is slipping on the crankshaft toothed pulley, but that would throw the cam timing off and with that much slippage you'd have the valves whacking the pistons by now. By the way, you are never supposed to back up the crank/cam/belt rotation. It's always supposed to be turned in the normal direction of rotation. You can introduce enough slack in the belt by reverse-rotating the engine to have the belt jump a tooth.

For sure don't go any further with the assembly until you find out what's making the noise.
__________________
Quotes to live by:
guessing gets expensive...drivinfaster
nothing is more expensive than a cheap BMW...c4harpe13

Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
BMW-CCA #441426
1995 318is "Bebe"; 1993 325is "Elvira" 1985 635CSi "Katja" 1984 633CSi "Sylvia"
HAVE I HAD MY MEDS YET?

Reply With Quote
  #5  
Old 06-18-2013, 01:39 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
Thanks. Yeah, doesn't sound right to me, but needed a second opinion.

I thought I had to remove the timing belt to access the coolant pump too, but I learned a way from Bentley how to remove the pump by only removing the spring and clip from the belt tensioner. The belt is still held pretty tight and the TDC marks are still lining up, so I know the belt's not slipping or jumping.

I was getting that sound even before removing the pump. It's not metallic like I'd expect if something was colliding in the chamber or cylinders.

I'll be removing the head today or tomorrow, and we'll see what's there.

Appreciate the feedback, and if anyone else recognizes that sound and can say what it might be, I'll be reading.
Reply With Quote
  #6  
Old 06-18-2013, 01:45 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
re. crankshaft rotation direction...I am turning the shaft clockwise (as you're facing toward the car from the front). That's correct, right? Or is my dyslexia getting the better of me?
Reply With Quote
  #7  
Old 06-18-2013, 03:23 PM
hornhospital's Avatar
hornhospital hornhospital is offline
D'oh, You kids!
Location: In the Grumpy Chair
 
Join Date: Jan 2008
Posts: 14,322
Mein Auto: 1995 318is / 1993 325is
Re: What Sound Should You Hear When Hand Turning Crank Shaft?

Clockwise is correct.

Sent from my MB860 using BimmerApp mobile app
__________________
Quotes to live by:
guessing gets expensive...drivinfaster
nothing is more expensive than a cheap BMW...c4harpe13

Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
BMW-CCA #441426
1995 318is "Bebe"; 1993 325is "Elvira" 1985 635CSi "Katja" 1984 633CSi "Sylvia"
HAVE I HAD MY MEDS YET?

Reply With Quote
  #8  
Old 06-18-2013, 07:46 PM
downhiller's Avatar
downhiller downhiller is offline
livin large
Location: des moines
 
Join Date: Oct 2007
Posts: 7,118
Mein Auto: 2012 hypermotard 796
almost sounds like the oil pump to me. for it giving that much noise for that slow of rotation
__________________
I know a lot about cars. I can look at a car's headlights and tell you exactly which way it's coming
Reply With Quote
  #9  
Old 06-19-2013, 01:44 AM
Billwill Billwill is offline
Officially Welcomed to the 'Fest
Location: South Africa
 
Join Date: Oct 2009
Posts: 521
Mein Auto: BMW E30 318i 1991
Quote:
Originally Posted by downhiller View Post
almost sounds like the oil pump to me. for it giving that much noise for that slow of rotation

Agreed....I would pull out the oil pump to have a look there
Reply With Quote
  #10  
Old 06-19-2013, 05:45 AM
7pilot 7pilot is offline
Git
Location: i dunno
 
Join Date: Feb 2011
Posts: 253
Mein Auto: 90 Ford Tempo
Are you sure that the toothed trigger wheel is not rubbing against some plastic piece?

The amount of effort seems ok, the rockers are moving.

m
Reply With Quote
  #11  
Old 06-19-2013, 06:43 AM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
Oil pump would be a pain, but I'd be grateful if that's all it turns out to be.

There's nothing rubbing on the belt or sprockets. The sound sure sounds to me like it's emanating from within the block, loudest from the rear half of the engine, like from cylinders 4, 5 and/or 6. I've not tried to listen from under the engine while someone else turns the crank. If it's coming from the oil pump, it sure is a trick of the sound reflection; but I'll get my son to turn it while I crawl underneath and try to get a bead on it.

I haven't had the time yet to remove the head, but it's definitely coming off since I'll need to check for warp and install a new gasket after the overheat. I was kidding myself to think I might not have to do that. With that off, I might find the answer to the mystery.
Reply With Quote
  #12  
Old 06-20-2013, 08:19 AM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
I'm wondering now if the state of the car's transmission would be the reason. It's an automatic and I think I left it in Park after putting the front end on jackstands. Can you even rotate the crank if the car's in gear or park? If so, maybe the sound is resistance from the flywheel.

I won't be able to check until later today, but I can't help but wonder out loud is this was just a wild goose chase because I left the transmission in gear.

Sound plausible? Or is my ignorance of the transmission/engine connection showing?
Reply With Quote
  #13  
Old 06-20-2013, 02:07 PM
hornhospital's Avatar
hornhospital hornhospital is offline
D'oh, You kids!
Location: In the Grumpy Chair
 
Join Date: Jan 2008
Posts: 14,322
Mein Auto: 1995 318is / 1993 325is
Park won't affect the engine rotation. Think about it. You start the engine with the transmission in park all the time. I doubt very much that's what's causing the noise, even if it's in gear. You can't turn the engine by hand fast enough to create enough pressure with the transmission fluid pump to move the transmission.
__________________
Quotes to live by:
guessing gets expensive...drivinfaster
nothing is more expensive than a cheap BMW...c4harpe13

Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
BMW-CCA #441426
1995 318is "Bebe"; 1993 325is "Elvira" 1985 635CSi "Katja" 1984 633CSi "Sylvia"
HAVE I HAD MY MEDS YET?

Reply With Quote
  #14  
Old 06-20-2013, 07:18 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
Yeah, that makes sense. Put the car in neutral and it didn't make a difference anyway. Still makes that clackity/growly sound.

I went to a salvage yard today to practice tearing down an engine before doing it on mine, and the engine on the guinea pig car (an '''87 325ic) didn't have any of that sound. Very quiet when I rotated the crank. I'm prepared to find havoc in cylinder 4, 5 or 6. I'll know this weekend.
Reply With Quote
  #15  
Old 06-20-2013, 08:11 PM
hornhospital's Avatar
hornhospital hornhospital is offline
D'oh, You kids!
Location: In the Grumpy Chair
 
Join Date: Jan 2008
Posts: 14,322
Mein Auto: 1995 318is / 1993 325is
Re: What Sound Should You Hear When Hand Turning Crank Shaft?

I think you're going to find it has nothing to do with the cylinders themselves. It's going to be something rubbing against the crank, much like putting a playing card in the spokes of a bicycle.

Sent from my MB860 using BimmerApp mobile app
__________________
Quotes to live by:
guessing gets expensive...drivinfaster
nothing is more expensive than a cheap BMW...c4harpe13

Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
BMW-CCA #441426
1995 318is "Bebe"; 1993 325is "Elvira" 1985 635CSi "Katja" 1984 633CSi "Sylvia"
HAVE I HAD MY MEDS YET?

Reply With Quote
  #16  
Old 06-20-2013, 08:45 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
After that last post, I was leaning toward your thinking too, and wanted to have my son crank it while I put my ear close to the flywheel area.

Lo and behold, the sound is much, much diminished; not just in volume but also no longer continuous through the whole rotation. Starting from top dead center, it 'growls' at two spots, through about 180-240 degrees maybe on the first rotation and about the same spot, maybe later on the 2nd rotation. I think. I might be off, but it sure did seem consistent with movement of the valves on 4 and 6...mostly 6.

I'll check again in the morning and I'll be removing the head tomorrow, but I'm tending to lean back toward the overheating having done something to the valves, hopefully just something like the guides.
Reply With Quote
  #17  
Old 06-23-2013, 11:48 AM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
So, I finally got around to removing the head this morning. As I mentioned before, the 'playing card in the spokes' sound had diminished considerably despite my having done nothing other than prepare the cylinder head for removal.

With the head off, the first thing I did was rotate the crankshaft. There was one brief 'growl' which I still am sure came from from the rear of the motor, like at cylinder 6, and then silence. Pistons driving very smoothly and quietly.

The valves and rockers are silent too, so still no idea what was causing that sound.

Stripping the head today and will take it to a machine shop tomorrow for a pressure check and warp check. Can't see any cracks and looks straight to me, using my file edge, but we'll see.

Don't know enough to diagnose things from the pistons and valves. Probably the first time these have seen the light of day since 1990. (cylinder 6 is shown, though the other five all look pretty similar)

piston #6

#6 valves

(Changed embedded pics into links to the pics since they're pretty large were messing up the page format.)

Looks nasty to me. One weird thing was the head had a missing seal on the intake valve rocker shaft, on the end opposite the sprocket, near #6 cylinder. Lots of gunk and grime there. Surprised I wasn't experience a lot of oil leakage as a result of that.

rocker shaft seal

Last edited by yibyab; 06-23-2013 at 04:31 PM. Reason: cleaned up links
Reply With Quote
  #18  
Old 06-23-2013, 03:09 PM
BigBoy740il's Avatar
BigBoy740il BigBoy740il is online now
Officially Welcomed to the 'Fest
Location: Arizona
 
Join Date: Jan 2012
Posts: 256
Mein Auto: 1989/1991 E30; 2000 E38
Re: What Sound Should You Hear When Hand Turning Crank Shaft?

Only one person came close to steering the OP in the right direction. Before tearing the block apart, I would check the oil pump's drive shaft, clearance of the CPS, and also pull the starting motor. It sounds like the starting motor gear isn't fully disengaged and could be dragging on the fly wheel. You could eliminate the piston and valves. If they were bent or broken the engine would either stop moving or have a metallic clunk when the piston hits the valve or crank.
__________________


Big Boyz with Bad Toyz.

Last edited by BigBoy740il; 06-23-2013 at 03:13 PM.
Reply With Quote
  #19  
Old 06-23-2013, 04:52 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
It's okay. I was leaning toward pulling the head anyway after overheating. It's been a good learning experience, and I'm getting to see just how filthy the motor is. Gunk, grime, weeping, brittle hoses...a good chance for an overhaul and to perform some of these projects for the first time.

If CPS stands for Crankshaft Position Sensor, I had removed that while still getting the sound you hear in the video. Nothing was rubbing up against any exposed toothed components, like the vibration dampener or the camshaft sprocket. Besides, unless it was a trick of the acoustics, it was coming from below the head, down in or below the block, under cylinders 4-6.

I'm still curious about the oil pump suggestion. I can't remember when I drained the oil during the tear down, whether it was before or after I noted the noise. I might have written that detail earlier, but I did pour back in about a quart of fresh oil to see if that made a difference. It didn't at the time, though the next day, the clackity-clack sound was reduced in volume and not continuous through the entire rotation. So, something changed. And with the head removed, turning the crankshaft makes no sound, other than the sloshing of fluid I presume is the oil in the sump.

The starter doesn't experience any mechanical movement just from rotating the crankshaft, does it?

The only potentially funny thing I noticed when stripping the cylinder head was that intake valves for #4 and #5 seemed to stick a little about halfway through the stem movement, and made a little popping sound. I can probably record audio of that for illustration, but the frequency of the 'click' wouldn't be the same as what I was hearing. The original sound had multiple clicks through just a few degrees of rotation, whereas if it was movement of #4 and #5 valve stems through the seal, I'd think the timing of the sound would be slower and/or shorter. Not to mention, the sound was very light as opposed to the quite loud sound when I was cranking the shaft.

Well, everything's pulled apart now and the head will be at the machine shop Monday.
Reply With Quote
  #20  
Old 06-23-2013, 05:10 PM
downhiller's Avatar
downhiller downhiller is offline
livin large
Location: des moines
 
Join Date: Oct 2007
Posts: 7,118
Mein Auto: 2012 hypermotard 796
even if the valves were sticking and clicking, they dont move fast enough to cause the sound that was being produced until you hit redline +. theres only one part within your engine that can potentially make that noise at the low of an rpm. im still saying its your pump.
__________________
I know a lot about cars. I can look at a car's headlights and tell you exactly which way it's coming
Reply With Quote
  #21  
Old 06-23-2013, 08:50 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
Thanks. I'll stop fixating on the cylinders. Would having drained the oil either exposed a bad pump or simulated an oil pump going bad by having no oil to send? I did ad a half quart of oil, and maybe that's the reason why the sound has gone away? I didn't think it made a difference because the sound didn't dissipate until the next day, perhaps after the little bit of oil had had the chance to collect in the sump.

I understand now what BigBoy was getting at in reference to the starter motor and flywheel, so that's still a possibility, though I can think of no reason why it would have stopped. As long as I've got easy access to it now, might as well have a look.

If my oil pump is failing, then that could contribute to the explanation for why the engine had started to run hot and overheated, though I think coolant leaking from a bad seal at the water pump gasket is the main culprit there.
Reply With Quote
  #22  
Old 06-24-2013, 05:32 AM
7pilot 7pilot is offline
Git
Location: i dunno
 
Join Date: Feb 2011
Posts: 253
Mein Auto: 90 Ford Tempo
I would advise that you get the head checked.
The valve in the pic looks like the stem is bent, unless it is a shadow . It does not appear to be centered in its seat.

m
Reply With Quote
  #23  
Old 06-24-2013, 02:13 PM
hornhospital's Avatar
hornhospital hornhospital is offline
D'oh, You kids!
Location: In the Grumpy Chair
 
Join Date: Jan 2008
Posts: 14,322
Mein Auto: 1995 318is / 1993 325is
I believe he's already said he was taking the head to be checked (which is a very good idea! ). It would be pretty dumb to put it back on without checking for flatness and cracks, and machining the valves, minumum

That's got to be an optical illusion with the valve. I see no evidence the valve ever hit the piston, either on the piston itself or the valve face. There'd be a pretty visible mark on one or the other or both if they'd hit hard enough to bend the valve.
__________________
Quotes to live by:
guessing gets expensive...drivinfaster
nothing is more expensive than a cheap BMW...c4harpe13

Ken Kanne, Silverhill, AL, E36 Forum Mod/Craigslist addict/Hoarder of all sorts of stuff
BMW-CCA #441426
1995 318is "Bebe"; 1993 325is "Elvira" 1985 635CSi "Katja" 1984 633CSi "Sylvia"
HAVE I HAD MY MEDS YET?

Reply With Quote
  #24  
Old 06-24-2013, 04:39 PM
yibyab yibyab is offline
Registered User
Location: San Diego
 
Join Date: Feb 2011
Posts: 29
Mein Auto: 1990 325i coupe
I dropped the head off at a machine shop this morning. If pressure check and inspection show no cracks, it'll get machined and cleaned.

That apparent offset of the valve is an illusion, probably a trick of the shadow. The valve stems are all straight and there's no evidence of impact with the piston. Pistonheads are extremely blackened by carbon, but show no sign of collision. I'm optimistic about the state of the head too, so I anticipate I'll be re building that on Friday and getting it back on the block. Then we'll see if the car lives, hopefully without that noise returning. I do not relish the idea of changing the oil pump.
Reply With Quote
  #25  
Old 06-24-2013, 08:03 PM
downhiller's Avatar
downhiller downhiller is offline
livin large
Location: des moines
 
Join Date: Oct 2007
Posts: 7,118
Mein Auto: 2012 hypermotard 796
why dont you just replace it while you have the block apart? itll be easier to lift up and get the pan off
__________________
I know a lot about cars. I can look at a car's headlights and tell you exactly which way it's coming
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E30 (1982 - 1993)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 07:53 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms