Hi folks,
I'm in the process of reviving a Laguna green '91 850i 6-speed manual.
The car has been off the road since around 2011. It was of course a non-runner when I got and before starting it for the first time, I did the usual:
new fuel pumps and fuel filters, fresh fuel, new spark plugs NGK BKR6EK (the ones in there were finger tight), checked ignition cables and found 6 to be dead so replaced them as well, new distributor caps and rotors, fresh oil and filter (10W40), turned the engine by hand... removed the belts and the car started relatively easily. The idle is okayish and it revs nice and easy.
But after a minute, there is this odd noise that I haven't experienced before, like rubbing noise, hard to describe but it should be obvious in the video.
Sounds like it could be from the bottom part of the engine but not sure. The noise is present even with the belts removed.
Any suggestions where to start diagnosing or the possible cause? I was thinking to drop the oil pan and see if I find something out of ordinary.
On a different topic, the brake fluid was black gue, cleaned as much as I could. When I try to bleed the system the fluid is only coming out of the front left corner. Removed the lines before the ABS pump and it's flowing so I'm thinking the hydro unit is clogged. Any suggestions here? The pump is NLA from BMW and not sure if anyone is refurbishing these. I'm guessing used one is the only option.
Can’t wait to see your progress with this 6speed!
Use a mechanics stethoscope, with that you can find the trouble maker easier.
Shogun tricks and tips for the E32 series are HERE!
There was a problem with the old version timing chain tensioner: 90bmw17- Group 11 Engine- Bulletin Number 11 10 90 (3144) , Woodcllff Lake, NJ October 1990 Service Engineering
SUBJECT: Modified Timing Chain Tensioning Rail MODEL:E31, E32 (with M70 engine)
Situation: A modified timing chain tensioning rail has been phased into production as of mid-June 1990. The new style timing chain tensioning rail incorporates a roller (sprocket) in addition to the plastic-coated sliding surface. The new configuration reduces the relatively high friction loads in cold operating conditions and thus reduces wear.
Installation Note:The timing chain adjustment distance has been reduced by 1 mm to5 +/- 0.5 mm due to the use of the new style timing chain tensioning rail. See repair manual for details on adjusting bming chain tension.
Parts Information:The new tensioning rail (P/N 11 31 1 725 682) can be installed retroactively whenever engine repairs are performed. Upon depletion of the current parts inventory the old part number will be superseded to the new part number, 11311725682.
https://www.bimmerforums.com/forum/s...hain+tensioner
Shogun tricks and tips for the E32 series are HERE!
That is pretty familiar sound actually, the cams are not getting enough lubrication, banjo bolts have backed out.
You think? That was my and friends initial guess, I asked Wokke if that could be the cause and he said no. To me it sound like a power steering pump that's not getting enough lubrication. Previous owner swears the car sounded perfect some 10 years ago when he parked it...
At this point, it can't hurt to remove the manifolds and valve covers, just not sure if I'll have time for that. I'm still waiting on the stethoscope so I'll check closer tomorrow.
I made some progress with the brakes today.
I disconnected 2 lines that go to the ABS pump from the MC and the fluid was flowing. Then I disconnected lines on the ABS pump one by one and the fluid was coming out, at first dark and then clean fluid. I had the power bleeder on the reservoir.
Now I'm getting a steady flow from the front left and right wheel using the power bleeder.
For the rear, the brake fluid is only coming out if I press the brake pedal which is rock hard and really difficult to press with the bleed screw open. Also, the pedal will only go half way and then stop, not to the floor like it should when the rear lines are open.
I know that the rear lines go into the ASC/T hydro pump after the ABS pump. So possibly clogged there? I'm also suspecting that the master cylinder might be rusted out from the inside and I guess not a bad idea to change it.
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my collection, H31 system explained https://www.bimmerforums.com/forum/s...teering-system
Shogun tricks and tips for the E32 series are HERE!
Soo, the stethoscope got delayed again but I used a long screwdriver and the noise is definitely most audible from the timing chain tensioner.
I adjusted it to be tighter by 3 mm more but it made no difference. I know guides are not a common failure on the M70 but we are talking about nearly 30 years old car that's been off the road for the last 10. Nothing lasts forever.
I'm thinking to replace the spring, the piston and leaking O-ring of the tensioner and see if it makes any difference. This is relatively easy and inexpensive.
If no difference, then drop the pan and look for plastic bits. If no remains of the guide, pop off the valve covers for a better look and check cam timing.
On top of that, it's smoking decently white/blueish smoke, not sure if it's just burning off from sitting or this engine will need a complete overhaul.
Any tips/suggestions?
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White Smoke is likely coolant, What does it smell Like?
Check your oil for the Chocolate Milkshake
Definative test is a compression check
There is a bit of condensation on the cap but not sure yet if it's just that or deeper, the car has been idling only for a few minutes and moved back and forth to feel the clutch and brakes. I didn't drive it properly yet so some condensation is to be expected.
I ordered parts for the tensioner and the compression tester.
Fixed!
Decided to change the timing chain tensioner today before dropping the pan. This is what I found.
The old spring was noticeable more compressed and shorter than the new one.
Scoring on the piston - from all the pictures that I saw of the piston inserted in the engine, I'm not really sure what would cause this or how it would happen? It looked like it was properly installed but hard to tell for sure.
Anyways, new stuff installed, it fired up drama-free and the engine is working beautifully! No more noise!
I'm very happy. Now just to see if the smoke will clear up. I'm hoping it will as I had the same thing with the previous E31, just a lot of condensation from sitting.
So far it's been only idling for a few minutes which is the worst thing, I'm planning to drive it around the yard once I come back from vacation in 7 days. But at least I can relax now knowing the engine sounds healthy.
Good job. I love your thread
Hi,
I also replaced these parts. (see image)
Unfortunately, the sounds are still there.
:-(
https://youtu.be/FmP8BewRnTc
1.jpg
Mine has been fine so far, I got it fully warmed up and drove it around the yard, even the smoke cleared up. It was just condensation.
In your case, I would start by removing the oil pan and see if you find anything there. If clean, then pop the valve covers off and look from above. I think lubrication might the issue as well.
Sreten! Love your videos, I learnt a lot from them.
I just pulled the trigger on a 6-speed 1992 850i which is not in such a bad shape. However, I'm noticing a very slight clicking/ticking noise when I'm close to it, seems to be coming from directly behind the timing chain on the Ansaugbrücke but I don't notice it getting any louder when I open the Oil fill cap. It does it at any temperature. What are the chances that I'm gonna have to pull off the valve-cover before I even registered it?
Last edited by Kylemontanaro; 03-02-2024 at 09:47 AM. Reason: typo of - off
besides the timing chain tensioner + spring there can be also other items making noise like hydraulic lifters etc, here is a Spanish language website with lots of pics showing what can break / making noise in the top of the M70 engine
SOLUCIONAR SONIDO A TAQUES EN BMW 750I E32 - Taqué nuevo frente a uno usado = new tappet vs used pics http://www.gti16.com/usr/coco/bmw_m7...70_taques.html
Last edited by shogun; 03-03-2024 at 03:09 AM.
Shogun tricks and tips for the E32 series are HERE!
Thanks mate, that was interesting to read! Could very well be the hydraulic lifters as well because I've noticed heavy carbonisation in some areas. I wouldn't be surprised if some of the lifters got a bit gunked up. I got an oil cleaner that I'm planning to throw in the oil system before I do an oil change but I'm not allowed to idle the 850 for 15 mins in the garage cause the neighbours would (rightly) complain. So I need to get it registered and drive it outside for a bit.
My wrenching buddy here in Japan made a good write up and pics of the lifters in his M70 Alpina B12 which we replaced in my garage https://e32b12.blogspot.com/search/l...valve%20lifter
Then you could have lose banjo bolts in the oil line in the head causing damage to the camshafts , Engl in Germany has Sicherungsbleche für die obenliegenden Ölleitungen der Nockenwellen (Motor M70) http://www.engl-production.de/sicherungsblech.html
Last edited by shogun; 03-03-2024 at 06:34 AM.
Shogun tricks and tips for the E32 series are HERE!
Oh man... that would be something! I will eventually open that up and have a look, but first I want to get driving around a bit to know the car a bit. I love working on it but I don't want to go through all the hassle to later realise there was something else I needed to fix when it was open.
Great write-up by your friend! These forums have really collected a treasure trove of info.
Sorry to go off-topic a bit, but do you know anything about computer diagnostics? I've dug through everything I could find the past few weeks, I have a laptop with a serial port, ADS adapter, Windows XP and DIS V44 & DIS V57 and I still can't get it to read. Considering the rest of the car has been so far playing nice to me, this has been a real headache.
for computer diagnostics there are other experts here which hopefully will chime in.
Shogun tricks and tips for the E32 series are HERE!
Thanks mate. I'll keep digging.
The sound that was at the beginning of the message thread that Sreten was struggling with comes from the timing chain tensioner wheel bearing, replace the timing chain tensioner rail m73 with the engine rail and the problem is gone. The sound may also disappear over time, this happened with my own m70 engine.
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