The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: tsal on December 27, 2009, 04:42:38 PM

Title: Engine Noise
Post by: tsal on December 27, 2009, 04:42:38 PM
Hi All!
Just picked up a 1979 R65 w/29k today. Motor seemed quiet when I test drove it this afternoon. Got it home, and now after a longer ride today I am getting a nasty noise coming from the engine only at idle. Go's away at 1500 rpms and up. Seems to only do it after motor warms up.  Hoping it is just valves needing adjustment. Took a short vid of it here: (you will need to to copy the link to your browser as this board will not allow me to link until after 2 posts

youtube.com/watch?v=e2_JE5g754c

This is my first airhead so...............
Thanks in advance for any thoughts/comments
Title: Re: Engine Noise
Post by: MrRiden on December 27, 2009, 04:51:54 PM
I'm suspecting the needle rollers have come out of the left jug exhaust rocker [just because it's louder in the front]. Pop the valve cover and keep an eye out for stray metal bits. Examine the rocker for play on the shaft. Keep us posted!
Title: Re: Engine Noise
Post by: proctorls on December 27, 2009, 05:18:03 PM
Tsal,

This sounds like a nasty introduction to the art of airhead maintenance.  I agree with MrRiden, and if it's bad news, at least you'll know immediately.

Find out from the previous owner if top-end maintenance was done recently.  Perhaps something was left loose, or, worst-case, the rocker shaft assembly was installed upside-down (or backwards, I can never remember which, which is why I have 2 shop manuals).

If the latter, the mechanism would have run fine for a while (test ride), but eventually the residual oil would heat up, run off, and leave the steel to meet the steel, with noisy and expensive results.

Needless to say, you should also check the other head for damage or misassembled parts.  If you have any question about what damaged or worn-out precision parts look like, you need to find a good mechanic.

Keep us posted.
Title: Re: Engine Noise
Post by: Rob Valdez 79 R65 on December 27, 2009, 05:43:33 PM
If you have a timing strobe light, use it to verify that it is not a sloppy timing chain (should not be worn if that is the true mileage).

If the chain is worn, your image of the timing marks on the flywheel will be jumping all around.
Title: Re: Engine Noise
Post by: the_admiral on December 27, 2009, 06:11:26 PM
hi tsal sounds like the timing chain to me as i had the same problem,no real hardship or expence to replace if your fairly apt with the spanners
Title: Re: Engine Noise
Post by: tsal on December 27, 2009, 07:24:39 PM
Thanks for all your replies, Glad I found this forum!! So......., I guess the fun begins:-)
I pulled the rocker covers, and everything seems ok, no metal bits or loose rockers that I can tell. Oil is clean, (however I don't know if its just been changed) The sound is coming from both sides and the front. Also, forgot to mention there is a squealing like wining sound coming from the front cover when started up cold. That sound gos away in a few minuets as it warms up, then the rapping sound at idle starts when fully warmed up. Not sure if there related or not??

I guess my first thing to buy is a good shop manual. Haynes??, or is another better?

Again, thank you for any help/suggestions . I will post findings as I go.
Title: Re: Engine Noise
Post by: tsal on December 27, 2009, 07:29:37 PM
Just curious, Is the tension for the timing chain adjustable on these motors?  
Title: Re: Engine Noise
Post by: Bob_Roller on December 27, 2009, 07:49:07 PM
The chain tension is adjusted by a small piston, that is operated with engine oil pressure, that pushes a rubber coated flat spring onto the timing chain to tension it  .

Also, you need to remove the positive cable from the battery, there are 'hot' terminals under the front cover of the engine, they have power to them regardless of the ignition switch position .

If you touch the cover to one of these, you can get electrical arcing, and possibly damage the charging system diode board .
Title: Re: Engine Noise
Post by: montmil on December 28, 2009, 07:17:21 AM
Awhile back, I had an unhappy noise at the front of the 81's engine. A Harbor Freight-grade stethoscope confirmed the racket was somewhere under the front cover... as in Timing Chain.

Motobins provided me with a complete timing chain replacement "kit". Everything needed in one neat bag.

It's a bit of a chore just getting to the chain but the entire process is doable at home.

Couple tips:  Be sure to position the engine at TDC before removing the old chain. The factory timing mark on the crank sprocket is pretty much invisible. Big dot on the cam sprocket; you can't miss it. A silver Sharpie will mark the two sprockets and help you realign them during chain install.

Stuff bits of paper toweling or clean rag into the multiple openings to the engine's guts. A bear to fish out a master link clip or screw! Extension magnet is a good tool to keep nearby.

My old oil pressure spring, although not rubber covered on my existing or new spring, had collapsed in length as compared to manual's specs and the new spring.

Noise go bye-bye with new chain. Sprockets were not worn beyond limits.  Hope this helps you. I'm betting the cam chain guides and followers are worn through to base metal. The metal/metal contact is the source of the terrible noise.

Monte
Title: Re: Engine Noise
Post by: Bob_Roller on December 28, 2009, 12:20:45 PM
Where abouts, on planet earth (assuming to are form this planet) do you reside ?
Title: Re: Engine Noise
Post by: tsal on December 28, 2009, 08:04:50 PM
Thanks guys. Yep, the more I listen to it, I think there is a Motobins chain kit in my future. I will check the timing this weekend with a strobe as recommended and look for the inconsistency to confirm. I want to do a compression check too. I don't know how long the previous owner has been running it like this, and as a result if there has been other damage done??. Oil looks like it was just changed, so no help there. Will pull the oil filter and dissect it.  Been doing a lot of reading of process of chain replacement. Have never done a job like this before, but I feel brave, and think Ill will give it a shot. Will keep ya posted.

Tony
Webster MA USA
Title: Re: Engine Noise
Post by: Rob Valdez 79 R65 on December 28, 2009, 09:02:23 PM
At the worst, if it is the chain, is it is hitting part of the castings on the front of the block (? - I think this is right) and wearing them away.  That could put big pieces of aluminum in your oil pan!

If this is the case, you should plan on pulling the oil pan to clean it out.  If you do, take care tightening the fasteners on reassembly.  These are steel fasteners going into aluminum threads.  It is a common theme on these bikes.  Beware!

In case your timing cover is damaged on the inside, I may have one that is in good condition you can have for shipping.  I'll just need to remove it to check it out.  
Title: Re: Engine Noise
Post by: montmil on December 29, 2009, 12:32:08 PM
Quote
...Been doing a lot of reading of process of chain replacement. Have never done a job like this before, but I feel brave, and think Ill will give it a shot. Will keep ya posted.

Tony
Webster MA USA

Get thee to the R65 dot org Photo Gallery. Check out the pics and notes from my timing chain replacement adventure.   Monte
Title: Re: Engine Noise
Post by: Rob Valdez 79 R65 on December 29, 2009, 04:12:19 PM
Make sure you have a digital camera and you take pictures of things as you are taking them apart.
Title: Re: Engine Noise
Post by: Ed Miller on December 29, 2009, 05:02:20 PM
How do you guys keep from getting oil all over those cameras?  My problem is it's not MY camera....

Title: Re: Engine Noise
Post by: Bob_Roller on December 29, 2009, 05:51:51 PM
One tool that you will need to accomplish this job, is an alternator rotor removal tool .

I don't know if it can be done without it .

It's about a $6 tool, its a hardened steel bolt around 4 inches long, with about 1 inch of threads removed at the end .
Title: Re: Engine Noise
Post by: MrRiden on December 29, 2009, 08:53:02 PM
Quote
How do you guys keep from getting oil all over those cameras?  My problem is it's not MY camera....

Stuff it in a baggie. Photo quality suffers a bit but it does keep the camera clean.
rich
Title: Re: Engine Noise
Post by: Rob Valdez 79 R65 on December 29, 2009, 09:52:06 PM
Quote
How do you guys keep from getting oil all over those cameras?  My problem is it's not MY camera....


It can slow the work pace a lot.  Lucky for me, I work slow, so it is no big deal.

I always wipe my hands before picking up the camera.

Get your own $50 camera.  I don't know if that is a realistic price - I paid $140 recond. on eBay, but they have a lot of cameras in the stores.  I don't know if cameras are getting cheaper or not.  How about Buy.com?


Title: Re: Engine Noise
Post by: Barry on December 30, 2009, 03:43:19 AM
4 or 5 Mega Pixel cameras are more than good enough for the job and there are plenty going cheap on ebay as everyone upgrades to newer models.  I bought a 5 MP Pentax for £12.

My only regret is it has only auto focus with no manual focus override which can be a pain on the close up shots. Maybe I'm not using it right but it seems to me that nothing automatic is always going to give perfect results.  Taking several shots usually means one of them is ok.
Title: Re: Engine Noise
Post by: Rob Valdez 79 R65 on December 30, 2009, 04:59:14 PM
Barry,

For closeups, just make sure it is on Macro mode.

The only thing I want manual focus for is doing arty stuff.

My camera is 4 mega pixel.  You all have seen what it can do.  If not, click on WWW in my sig line.

(https://bmwr65.org/smf/proxy.php?request=http%3A%2F%2Fwww.pbase.com%2Ftomfarr%2Fimage%2F81102409.jpg&hash=b5511af24091f420b0ebdaef1b13a3804518958f)
Title: Re: Engine Noise
Post by: tsal on December 30, 2009, 07:28:34 PM
Rob, Thank you very much for the offer. Hoping I won't need it.

Monte, What great pics! That really helps me out a lot.

  
Title: Re: Engine Noise
Post by: azcycle on January 02, 2010, 08:34:27 PM
I took "my" r65 out for a spin yesterday and believe I might be getting the same sound from the front. Will confirm tomorrow.  What is the average miles one would think these parts would wear out?  I believe my r65 is around 55k.  The gauges were removed around 45k so I'm only estimating mileage since then.
Title: Re: Engine Noise
Post by: montmil on January 02, 2010, 10:12:54 PM
Quote
...What is the average miles one would think these parts would wear out?  I believe my r65 is around 55k.

That dovetails with my '81's cam chain swap out. Of course, I don't have much of the bike's prior history, so...     Monte
Title: Re: Engine Noise
Post by: Bob_Roller on January 03, 2010, 07:19:01 AM
I've got 82,000 miles on my '81, I'm the original owner, so I do have a complete history on the bike .

I replaced the timing chain at around 45,000 miles, for a noise, that turned out to be the transmission bearings being damaged by water getting into the transmission .

All of the other parts to tension the cam chain are original .

After hearing about other bikes with cam chain noise, I am tempted to order a cam chain replacement kit from Motobins, with my next order .
Title: Re: Engine Noise
Post by: montmil on January 03, 2010, 08:53:17 AM
On my 1981 R65, the noise culprit was not so much the chain wearing out and slapping stuff around but both the tensioner and guide shoes going south on me.

These plastic and metal components have 'shoes" of a plastic material which are in constant contact with the chain. My tensioner-side shoe had worn through to bare metal, hence the horrible noise that occurred at different rpms and engine load. I point my finger at the guilty party being the tensioner spring that had collapsed way past the OEM length specification.

The Motobins cam chain replacement kit saves ordering errors and is priced less than the total of individual bits.

My biggest effort was removing the exhaust system as one complete unit due to the rusted and possibly fragile cross-tube joints. A Rubic's Cube that was!

Monte
Title: Re: Engine Noise
Post by: Bob_Roller on January 03, 2010, 08:58:01 AM
Monte,

The spring you mentioned, was it the one that goes under the piston that pushes the tensioner shoe to contact the cam chain ?

I don't think I saw one in the Motobins cam chain replacement, kit that I got for the LS .
Title: Re: Engine Noise
Post by: montmil on January 03, 2010, 09:01:02 AM
Quote
Monte,

The spring you mentioned, was it the one that goes under the piston that pushes the tensioner shoe to contact the cam chain ?

I don't think I saw one in the Motobins cam chain replacement, kit that I got for the LS .

That's the one, Bob. My new one was half-inch+ longer and met the BMW spec length. Not rubber covered -old one or new- as someone hereabouts mentioned.
Title: Re: Engine Noise
Post by: tsal on January 03, 2010, 07:02:39 PM
I checked the timing with a strobe and sure enough, the mark was bouncing around. Ordered the Motobins chain kit. Also new exhaust nuts as the ones on the bike look like they never been off. Going to cut the old ones off rather than take a chance messing up the  threads on the head. Also ordered a service manual, and rotor removal tool.
Title: Re: Engine Noise
Post by: montmil on January 03, 2010, 08:32:07 PM
Quote
I checked the timing with a strobe and sure enough, the mark was bouncing around. Ordered the Motobins chain kit. Also new exhaust nuts as the ones on the bike look like they never been off. Going to cut the old ones off rather than take a chance messing up the  threads on the head. Also ordered a service manual, and rotor removal tool.

You should be golden.  [smiley=thumbup.gif] Monte