fumes and whine(ing) -long

[bimmerboy73]

i've been taking my coupe on some 'shake down' drives around the baltimore beltway to get acquainted with the car and try to get a sense of all that might be ailing her. So far, mostly very good. heres what i've found to date:

1. Carbs are a definite candidate for a rebuild. Problem is, i'm not exactly sure of the spec. I've contacted the PO and he's not quite sure either other than he was told that they were the 'stock carbs' by the guy he bought the car from. They look like the standard issue dual webers with the cowel and snorkel breather element. But the exact model i am not sure of. Their condition seems to be worsening by the day with the backfiring occuring pretty regularly on down shifts and decels. Would bad carbs cause a strong fuel odor? i'm assuming they are probably way out of tune and are providing way more fuel than is necessary (gas mileage has been atrocious). Where might one find the part number? Does anyone know of shops in the mid-atlantic region that install / rebuild carbs and specialize in vintage bimmers? Was also told by the PO that there's an elec. choke installed. Would this effect the type of rebuild kit i purchase? I was considering doing teh rebuild myself...

2. Exhaust and occassionally gas fumes leaking into the cabin - I've narrowed down the location of the exhaust leak to the flanges just upstream of the first resonator and the second set down from the manifold. What i cant figure is where the fumes are getting into the car. I've replaced the weather stripping that separates the fresh air intake from the engine compartment and have nosed around under the center console but cant seem to pinpoint it. Is there a typical culprit in these situations? Also - probably related to the carbs - is a strong fuel odor coming from the engine compartment. Did some digging on the site to try to troubleshoot the source (if not the carbs). Interestng enough, the hose that comes from the charcoal canister under the battery and connects to the air filter was plugged, seemingly intentionally, with a bead of silicon. Removing the clog seemed to help solve the fuel smell i was previously encountering in the trunk... but i might just be crazy now from inhaling all of the carbon monoxide

3. whirring sound from the tranny - when the engine is under load above 55 miles per hour there is a distinct and obvious whirring sound coming from the transmission. (car has a 265 5 spd tranny mated to what was previously a stock CSA driveshaft). I know the hardy disc is in need of replacement but have been told that even when worn, they cause a vibration, and not any audible sound. Any ideas what this could be? the sound goes away immediately upon lifting off of the gas at any speed above 55. below 55 it doesnt make a peep under load or otherwise. Shifting is smooth... no slips or stutters and the revs seem to be normal at speed. Could it be the weight of the tranny fluid? PO used a mix of organic and synth. fluid in the transmission (he was told to do so) for smoother shifting. pre purchase inspection mechanic recommended trying a heavier weight oil... any ideas?

4. on the cosmetic end - noticed that the bodywork just below and behid the front bumper has been pushed in some and has deformed the metal. (pushed inward on the underside and buckled a small section of the metal vent openings on the top facing side). - i'll post some pics. Not sure how exactly i should approach a repair. Is the sheetmetal on the cars tempermenatl enough to warrant taking it to a bimmer specialst? or is it something i can rely on a reputable bodyshop to handle?

Any help from the e9 vets would be greatly appreciated! Thanks in advance!

PS - Cant believe all the looks and compliments the car gets. I'd read the stories of passers by heaping praise on the classic coupes wherever and whenever they were seen, but i never expected this. And i'me pretty used to the compliments given my other cars are an Audi TT coupe and a sport tuned, rotary powered Mazdaspeed RX-8. The Bimmer takes the cake... and i havent even begun to bring her back yet!

 

[Honolulu]

some tips

Smell, smell, smell the gas... they all do.


There are numerous places for a gas smell to originate and get into the cabin. You should use the search function, this subject was beat to death and then some, long ago, many times.

But what the hey, recap. Start at the back. Leaking gas tank, especially around the perimeter weld. Leaking fuel gage sender, replace o-ring. Leaking evaporative system starting with hose from filler neck, to canister over right wheel well, to hose running forward through pass. compartment to charcoal filter. Leaking trunk seal, passenger cabin is at lower pressure than trunk - true! - and pass cabin sucks in vapors from trunk.

Recap the front: leaking carbs, fuel pump, fuel hoses - big fire risk here. Leak in evap system - you unplugged it, did you plug it into the bottom of the air filter housing? Line to/from charcoal can open - most of us long ago hurled the charcoal can into the weeds.

If you in fact have weber carbs, after high mileage they like to leak at the throttle shafts and make an even idle speed impossible. You can find 32/36 weber pictures in lotsa places, and then don't look like the stock Zenith carbs. Search 'em out, look at what you have, you'll know.

Not only the hood to body seal needs to be good to prevent under-hood smells from getting into the cabin. There are three tubular drains from the gutter forward of the windshield, where the wiper motor lives, that are supposed to have rubber seals. Most of these seals have long since disintegrated, or they are filled with leaves and crap. Clean 'em if you have 'em. Consider replacements if not, from CNPR or Mesa or ....? Check the seal where the steering column passes through the firewall. Is your car provided with AC? Check where the hoses pass through the firewall.

There's lots of other possibilities, these are some of the more common. Search function is your friend.

Will you work on the car yourself or pay someone? Ever tune multiple carbs?

 

[Bill Riblett]

Some things to think about:
Don Miller's Blueridge Sportscars LTD in Baltimore is knowledgeable and familiar with coupes. 1796 Union Ave, Baltimore, MD
(410) 662-4746 They are off I-83, a few miles north of downtown.
You might find it money well-spent for them to do something like a post-purchase assessment of your car.

1. Stock carbs were Zeniths, but many CSs had them replaced with Webers and most of those were 32/36s. These come in 3 choke configurations: manual, electric-heated, or water-heated. Before you start on the carbs, first make sure that the ignition system is in good shape and that the timing is set properly.

2. check that all the hoses to the vapor recovery tank in the trunk are intact and hooked up.

3. Getrag 265s do seem to be somewhat noisy and the oil mix in yours was an attempt to quiet it some. There is a foam 'doughnut' between the shifter and the body, under the car. Is that there and intact? It cuts the noise a lot. Also, the back of shift tower should be mounted to the body with a rubber bushing, but if it were just bolted to the transmission tunnel sheetmetal, this will transmit a lot of noise.

4. A competent bodyshop should be able to repair this damage.

Finally, email Bill Williams [email protected] and ask to be put on his mailing list for mid-Atlantic vintage BMWs and come out to some of the drives, etc. There will be a get together in Herndon, VA on April 12.

 

[bimmerboy73]

honolulu,

Thanks for the info. yeah, i've checked all the culprits you mentioned-Its amazing how much info there is in this forum. The gas smell in the trunk sems to have dissipated some and is no longer lingering in the cabin when the car is off or left to sit overnight. It was pretty bad the first time i filled up. Part of the problem was that the rubber seal around the gas filler had come off of the metal surround

The carbs seem to be the culprit up front. Fuel hoses look to be in good shape as do all of the connections (that i can see). The dash-pot has some fluid residue dripping from the bottom of it (not sure if this is normal of=r exactky what type of fluid it is).

Checked the drains forward of the windshield and they are all clear. But i will check the seals at the steering column and AC hoses

I was intending on attempting the rebuild and tune on my own to familiraize my self with engine...although i have my reservations. I've worked on all the cars i've owned doing everything from engine tune ups to shock replacement and brake work. At this point, i just want to get the car running correctly though, so i might break down and just have a reputable shop take care of it for me... if i can find one locally.

photos of the carbs here -http://s257.photobucket.com/albums/hh225/rysejones/?albumview=link

 

[bimmerboy73]

Bill,

Thanks for the advice. I'll check into the shop in Baltimore this week. Thats exactly what i was looking for!

 

[bimmerboy73]

Blue Ridge

Bill -

just stopped by Blue Ridge today during lunch (ends up i work about 2 miles from them). Time well spent. For current or potential vintage bmw owners who might be looking for a decent shop in the baltimore area, they are worth a visit. Don seems like a great guy. Ended up talking to him and Paul for about 45 minutes about coupes. I'm set up for a thorough once over and carb rebuild next week. Thanks for the tip!