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Being that today was superbowl sunday here in the US, and i could care less, i spent the day working in the garage.
On the agenda was cooling system, hoses, thermostat, and water pump. Of course, i had 3 hoses i didn't require, and one hose was missing that i needed, so the project is not complete.
I also, for the life of me, can not get the metal o-ring/seal out of the thermostat housing. Heat, etc doesn't seem to help. I'm going to drop it off at my local machinist tomorrow to let him remove the old seal and press in the new one. (my old thermostat was bad, car was not getting up to temp).

While i was in there, access to the timing chain tensioner was as good as it's going to get, so I installed the S50 unit, which went almost too easily.

Though my car seemed to run well, and last time i checked (about 7 months ago honestly) the resonance flap self test worked, but my vacuum hoses looked horrible, they were all cracked and more than one broken (including the one to the smog pump). The crankcase vent hose also disintegrated in my hands. Can't wait until it's back together, i must have had a lot of vacuum leaks with the condition of the hoses.
I've been stocking up on these parts over the past few months, waiting for the day to get it all done, since many jobs are overlapping.
Many thanks to those who have posted the how to's here and on bmwe34m5.com, which made the jobs much easier.

Need to run to the dealer to return the 'extra' hoses, and get the ones i need ordered. Hopefully, they're already in the US and i'll have them in a day. I hate leaving the car laid up apart.
A couple of pics attatched below.
 

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Hey Mike,

I had the same problem when removing the old metal seal within the thermostat house. I also ended up bringing it to a machinst.

The self-test for the resonance flap is no garantuee that it functions as intended. It only tests the hardware, but one of the input sensors, the throttle position switch is left out. The only proper test is to 'manually' rev the engine above 4500RPM by pushing the throttle lever on the throttle bodies against the stop and check it's operation (off course with a fully warmed up engine). Replacing the vacuum lines is mandatory after all these years. My old vacuum-hoses fell apart once I pulled them off.

Chain tensioner is very easy, once you know the trick. But check the chain-length after that by placing the cams at TDC and read the distance of the OT marks on the vibration damper and the timing-chain cover. A slight difference is OK, but not more then 3mm.
 

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what needed to be removed to get to this picture?

what are the hoses that were in worse shape, so I can focus on those first. I only have 110k miles, but it is a 1991... and rubber don't last forever.
 

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what needed to be removed to get to this picture?

what are the hoses that were in worse shape, so I can focus on those first. I only have 110k miles, but it is a 1991... and rubber don't last forever.
Pretty much just the plenum. There is an excellent write up on bmwe34m5.com, can't remember the page, but look for 'resonance flap overhaul', has instructions to get off the plenum and a lifesaving schematic of all of the vacuum hoses. Plenum comes off in about 10-15 minutes.

The thing about what do i replace first, it all overlaps from a labor perspective, i would have had it all done in an afternoon had i not been missing a heater hose that resides under the plenum. If you're going to the hassle of draining the coolant, may as well replace all of the hoses at once, and if you're going that far, why not do it all and replace the thermostat and water pump! My aux coolant pump was also bad/ previously bypassed, so i was replacing that too. While the plenum is off, the idle control valve is right there, so at least replace all of the hoses going to it, maybe clean it out with some carb/throttle body cleaner. Ditto for the crankcase vent hoses and oil return line from the bottom of the plenum. See what i mean, every project begets another half dozen.

On my car, with 147k on the clock, the vacuum hoses were shot, coolant hoses seemed ok, but worth replacing. Crankcase vent hose that goes from the valve cover to the plenum disintegrated as i removed the plenum. Much of the hose system was covered with what i'll call structural grease. The grease is what's holding it all together, once you wipe it off, you find there is no rubber under it.

So the missing hose, and a few other bits are ordered and i should have them on wednesday. Machinist says no problemo to get the thermostat housing back by then too. So hopefully by next weekend (or sooner if i get a free evening), it'll be running again, better than ever.
Mike
 

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Where can you get all the hoses from? I've actually got the diagrams as a PowerPoint presentation, and it makes it all look resonably simple. Is it just a case of buying each individual pipe from BMW, and if so does anybody have the part numbers?

Cheers

Mark
 

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I'm next on the hose replacement

Looks like I'm next on the hose replacement. With 187.000 km under the belt with all original parts in place, I think it's time. Engine runs fine though but any preventive maintenance wouldn't hurt!

Between 2.500 and 3.000 rpm I hear a small metalic vibrating sound for a very short while coming from under the hood. Just like a piece of metal plate resoning aganst something...

Would that by the resonance flap which you guys talk about?

W.
 

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Looks like I'm next on the hose replacement. With 187.000 km under the belt with all original parts in place, I think it's time. Engine runs fine though but any preventive maintenance wouldn't hurt!

Between 2.500 and 3.000 rpm I hear a small metalic vibrating sound for a very short while coming from under the hood. Just like a piece of metal plate resoning aganst something...

Would that by the resonance flap which you guys talk about?

W.
I think the resonance flap comes into play at a little over 4000 rpm, so I doubt it is that. However, any stange noises could be worth investigating:thumbsup:

Lantz
 

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Discussion Starter #10
Where can you get all the hoses from? I've actually got the diagrams as a PowerPoint presentation, and it makes it all look resonably simple. Is it just a case of buying each individual pipe from BMW, and if so does anybody have the part numbers?

Cheers

Mark
i searched thru realoem.com and brought the printout with my part numbers to my dealer. I have a long history with my dealership, and the parts guys take good care of me.
As i found, there are different versions of several hoses depending on the market and equipment.
 

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can you share the ppt file?
 

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go to: http://autos.groups.yahoo.com/group/bmwe34m5/files/Parts Information/ and download the excel spreadsheet. I'm in the middle of replacing most of my hoses and the PNs and recent prices from my order are in the spreadsheet. (I didn't buy all of them, but all the necessary PNs should be there.) Compare with realoem.com if you're not sure where they go. Or buy the EPK discs from ebay.
 

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help!! I tried loggin in and verifying address, but still can't download the xls. I am in the process of getting all the hoses related to cooling.
 

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It looks like you have an E34 525, which won't share many, if any, hoses with the M5. If you do have an E34 M5, then hang on another day or so to be added to the yahoo group. the moderators are usually on top of things. send an email to eleex (at) yahoo.com and I'll send you the spreadsheet.
 

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Discussion Starter #16 (Edited)
It looks like you have an E34 525, which won't share many, if any, hoses with the M5. If you do have an E34 M5, then hang on another day or so to be added to the yahoo group. the moderators are usually on top of things. send an email to eleex (at) yahoo.com and I'll send you the spreadsheet.
he also has a 91 m5, just needs to update his sig file!

fwiw, i just printed out the pages from realoem.com, then went to the dealer and went thru them with my parts guy. Problem with that was we were short one hose, and had 3 extra's. They of course took back the extras, and i needed the crankcase vent hoses too, once i got the car apart, so wasn't much extra delay, they were in the US, so i had them in a day or two.
 

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Discussion Starter #17
just updating my own thread...
All back together, running much nicer, i must have had many vacuum leaks, and probably not a properly functioning resonance flap. Mid range torque is much smoother, engine seems happier overall.

I will admit it all went easier that i thought, i had some concerns over the chain tensioner, but that was quite easy. I was also worried that i would have some issues bleeding the cooling system, i opened the bleed screw and slowly filled the system, and it pretty much took care of itself.

Noticed how mad my motor mounts looked while doing the lower hose, so that is next on the to do list.
:cheers:
 
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