SOLVED: 1988 528e Purge Valve Part Number

E28 technical advice asked and given! Troubleshooting, modifications and more.
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matreyia
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Joined: Dec 22, 2021 1:05 AM
Location: Houston

SOLVED: 1988 528e Purge Valve Part Number

Post by matreyia »

Hello Everyone, I been searching online and in this forum and can't seem to find the answer.
Does anyone know if a charcoal canister purge valve still exists and if so, would you know the part number and where to get one?
I'm working on replacing all emissions components and eliminating all possible emissions related check engine light (CEL - not the "check light").

I've already ordered a new gas cap, new charcoal canister (ouch), and new charcoal expansion tank located in the trunk. I also plan to replace all hoses with silicone platinum hoses.

1988 e28 528e automatic.

Thanks for your help and knowledge.

VT
Last edited by matreyia on Jun 02, 2022 5:11 PM, edited 1 time in total.
Mike W.
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Re: 1988 528e Purge Valve Part Number

Post by Mike W. »

Might it be #25 in the diagram in the link?

https://www.realoem.com/bmw/enUS/showpa ... Id=16_0097
matreyia
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Re: 1988 528e Purge Valve Part Number

Post by matreyia »

It is in that diagram but that isn't the right unit for a March 1987 and older model which uses electronic controlled valve. Can't seem to find it anywhere.
Mike W.
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Re: 1988 528e Purge Valve Part Number

Post by Mike W. »

Realoem isn't perfect, but it's pretty good. One problem however is sometimes the images are for a variety of different models and not really very accurate, they might list a different P/N, but the same pic if it performs the same basic function. Regardless, is it a vacuum or electric valve? Here's a couple I ran across,

11741277566

Image

11631706273 which is used on 535i's, but super etas used a funny mix of parts sometimes so it's possible it's the correct one.

Image
turbodan
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Re: 1988 528e Purge Valve Part Number

Post by turbodan »

Your 88 will only display a check engine light for a fault detected in the coolant temp sensor, intake air temp sensor, oxygen sensor or air flow meter. The purge valve can be completely disconnected, cap the fitting on the throttle body, cut the hose back and stuff it into the frame rail.

From what I'm reading the original valve with the rubber gizzard molded onto it is discontinued and the replacement is a more modern in line style valve.
matreyia
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Re: 1988 528e Purge Valve Part Number

Post by matreyia »

Would a leaky hose to the purge valve cause an o2 sensor fault? I replaced two sensors in two weeks and still comes up after erasing the fault. replaced the o2 sensor heater relay too. replaced the hoses with silicone, only the purge valve hose is old as is the fuel tank vapor hose going to the front charcoal canister. Idle control valve big hose on throttle body is also new.
turbodan
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Re: 1988 528e Purge Valve Part Number

Post by turbodan »

Easy way to check is to cap off the nipple it goes onto and eliminate the possibility.

The check engine light can be caused by an excessively lean or rich mixture or a bad o2 sensor. Could be a lot of potential causes other than air leaks.

Does the AFM look like it's ever been messed with? What's the part number on the top?
matreyia
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Location: Houston

Re: 1988 528e Purge Valve Part Number

Post by matreyia »

I think the AFM is stock and virgin, but old as dirt. This only started happening AFTER I sprayed down the engine to clean it - like pressure washed...which is a no no, but I thought it would be ok since I would let the car sit for a few days after blowing water dry. Maybe water/moisture got into the AFM? Because it has a brand new o2 sensor installed now AFTER the episode.

I did order a refurbished AFM from Cardone that should arrive in a few days. Will install and test drive and update.
Thanks for the response!

VT
turbodan
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Re: 1988 528e Purge Valve Part Number

Post by turbodan »

Check your coolant temp sensor connectors for water ingress and corrosion.

I keep water far away from my engine compartment. They just aren't as waterproof as they used to be.
Mike W.
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Re: 1988 528e Purge Valve Part Number

Post by Mike W. »

Any connection or plug is suspect after cleaning with water, been there, done that. Including the spark plug cables/connectors. Hopefully you have compressed air, remove one thing at a time and blow out. Use a shop vac in reverse if you don't have air, low pressure, but lots of volume. Or a hair dryer.
matreyia
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Re: 1988 528e Purge Valve Part Number

Post by matreyia »

Ok, here is my update... I hope you can give some guidance after this.

NEW ITEMS:
new o2 sensor
new AFM refurbished
new silicone hoses to the fuel pressure regulator, and the other hose opposite that hose
new valve cover gasket
new coil, spark plug wires, distributor
new timing belt, all other belts
new seal on front camshaft (crankshaft? on top engine area)
new water pump, thermostat
new outer coolant sensor same color as old (farthest away from cabin on the thermostat)
new inner coolant sensor (suspiciously different color from old sensor)
new charcoal canister hose to purge valve solenoid
new intake manifold gaskets (maybe not tight enough???)
new exhaust manifold gaskets (maybe not tight enough??)
new PCV solenoid short connection hose on throttle body
new intake boot

Everything works now - lights, AC, heater, EXCEPT for this 02 sensor error (two blinks on check engine light)
And the ABS sensor warning with smushy brakes need to be addressed. Will install new master cylinder and replace front ABS sensors.

TEST DRIVE RESULTS: car behaves like modern car of 127 HP. No scare surprises on acceleration and shifting. Feels totally in functional.
Drove about 25 minutes around neighborhood with acceleration up to 55 mph with no problems.
Heater and AC tested working 100%. No hestitation, very smooth stable idle and acceleration. Coolant temperatures very stable, does not go to the middle of the thermometer in dash.

So I got it up to temperature and it feels great... I thought maybe the drive would shut off the o2 error but alas, it remains on the dash.

You guys think I should go ahead and take those mentioned parts out to check for water damage?
Also, I am suspicious of that inner coolant sensor next to the main coolant sensor...maybe I should change back to the original unit?
Finally, I will double check the valve cover bolts, the intake and exhaust bolts and retighten then if they are loose.

Any additional ideas greatly appreciated! I am totally stumped. I wish I could get this thing inspected last week! so i can use it for my daily.
matreyia
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Location: Houston

Re: 1988 528e Purge Valve Part Number

Post by matreyia »

Update: tested original coolant temperature sensor and no dice... still o2 error returns.
tomorrow will remove intake manifold to check for any damage from o ring of the oil return tube to the oil pan.

replacing starter, master cylinder, both front abs sensors while I am in there.
matreyia
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Location: Houston

Re: 1988 528e Purge Valve Part Number

Post by matreyia »

Update: Tuesday May 31, 2022
Just changed the starter and double checked the metal tube from the intake manifold to the oil pan. It was off kilter at the top junction where there was no sealing, so I pulled and tugged and it snapped into place upwards and now it does not move at all. I hope that this was the source of the vacuum leak that kept triggering the o2 sensor check engine light.

I have to replace the master cylinder and both abs sensors now, then will do a test drive and report results.

VT
matreyia
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SOLVED - 1988 528e Purge Valve Part Number

Post by matreyia »

O2 sensor error was due to oil return pipe that connects from the bottom of the intake manifold to the oil pan. The top connector was not full seated into the intake manifold and caused a serious vacuum leak that triggered the o2 sensor error. Tugging and wiggling the pipe snapped it into place and the bottom spring supplied the constant upward pressure to keep it sealed with the new o ring.

If you take off the intake manifold then be very careful upon reinstalling that metal pipe.
garageboy
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Re: SOLVED: 1988 528e Purge Valve Part Number

Post by garageboy »

Sorry I got to this discussion late, and glad you got it working again.

But I would really avoid replacing parts without cause on an E28. If this was 1990, where lotsa cheap factory parts were widely available, it would be less of a problem. But the parts you purchase today may not have the longevity you seek. And in general, when you're trying to solve an equation, one does not simply add more variables to the equation; that is precisely what you don't want to do. It's the same with a car. Replacing parts when you don't understand why is the opposite of what you should do. When trying to diagnose a fault, especially on a very simple and straightforward design like an M20 or M30, there is always a cause-and-effect, which, of course, you eventually found.

The engine cleaning put all electrical connectors at risk. That was the first and only place to start. Every connector must come apart and be cleaned out. Then air leaks. Just about every problem on an M20 or M30 is either a loose/bad connection or a leak in an air hose. In my opinion, assuming you didn't go to a BMW dealership and turn over your first born in exchange for all those parts you changed (it would have been thousands of dollars if you had), the car now may have other problems develop with all of these new parts... like coil (NEVER fails) or spark plug wires (many cheap ones out there that should never go near an E28). These are not maintenance items that you would have replaced at some point anyway.

And finally, the only way to clean an engine of an E28 is slowly and carefully, part by part. There are no shortcuts there. Remember the first rule: do no harm. Get a Bentley manual. Good luck!

p.s. when you say you "replaced distributor", do you mean the distributor cap and cap rotor? What did you use for parts?
matreyia
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Joined: Dec 22, 2021 1:05 AM
Location: Houston

Re: SOLVED: 1988 528e Purge Valve Part Number

Post by matreyia »

All parts were replaced as normal restoration protocol with oe or oem parts. Some were so decayed it was obvious they needed replacement. Car runs silky smooth now. Only other thing is this stubborn ABS light won't go out. Plan of action:

Done:
1. replaced both front abs sensors - old ones totally crumbled
2. clean rear abs sensors and abs rings

To Do:
3. cut rear abs sensor connectors and solder connection
4. replace both relays located on the ABS hydraulic unit in the engine bay

If all else fails, pull the damn light bulb out and drive with no ABS.

I'm all ears if you have any advice on this ABS tomfoolery.
turbodan
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Re: SOLVED: 1988 528e Purge Valve Part Number

Post by turbodan »

I imagine the air leak here was also dropping some oil right?

Just sorted the same problem out on mine. Last guy that put it together must have been missing a chromosome or something. Had threaded the spring over the lip on the tube so it was freely floating on the middle section of the tube, applying no force on anything. Tube had dropped down a good half inch and was creating a massive air leak and substantial oil leak as well.

I don't know how somebody could put it together like that but they sure did.
garageboy
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Re: SOLVED: 1988 528e Purge Valve Part Number

Post by garageboy »

matreyia wrote: Jun 12, 2022 10:32 AM All parts were replaced as normal restoration protocol with oe or oem parts.
"Normal restoration protocol"??? WTF are you talking about? "I have no idea how old the part is or whether it is good or bad, so I'm replacing it"? That's not a protocol. There's a lifetime of difference between OE and OEM in many circumstances. Unless you have years of experience with parts for these cars, you cannot just guess your way through it. It doesn't work that way.

Everything you have done has run precisely COUNTER to the advice of two of the most learned members of our forum... as well as mine... If I were you, I'd get rid of the car. It's not for you and the way your brain works. Everything you have done thus far, from the "power wash" to every single part that you should not have replaced, has, in my opinion, harmed this car.
matreyia wrote: Jun 12, 2022 10:32 AM Plan of action:
Your only plan of action is to take it to a skilled mechanic, spend the money, and suck it up and let your ego accept that you harmed your car because you simply did not know what you were doing. We've all been there at one point or another. ME TOO. The difference seems to me that I'm willing to STFU and learn from my stupid mistakes, whereas you seem to declare "Mission Accomplished" (ok, "solved") and continue to rationalize your mistakes as necessary protocol.
matreyia wrote: Jun 12, 2022 10:32 AM If all else fails, pull the damn light bulb out and drive with no ABS.

I'm all ears if you have any advice on this ABS tomfoolery.
This is simply not the car for you. The only tomfoolery going on is your diagnoses. If you disable the ABS light, I hope you are planning on keeping the car until you are an old man and never sell it. That tells me more than anything that I am unable to help you. Clearly, I'm far too sarcastic. I'm out. I'm sorry. Good luck.
matreyia
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Re: SOLVED: 1988 528e Purge Valve Part Number

Post by matreyia »

What a strange response.

If there is a part that is clearly visibly damaged with cracked or missing or falling off parts..or visibly leaking, you replace that part as per normal protocol.

I have no idea why you got worked up, but ok, see you later. I have no time to spend on people like you. Good lord.
matreyia
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Location: Houston

Re: SOLVED: 1988 528e Purge Valve Part Number

Post by matreyia »

turbodan wrote: Jun 12, 2022 8:46 PM I imagine the air leak here was also dropping some oil right?

Just sorted the same problem out on mine. Last guy that put it together must have been missing a chromosome or something. Had threaded the spring over the lip on the tube so it was freely floating on the middle section of the tube, applying no force on anything. Tube had dropped down a good half inch and was creating a massive air leak and substantial oil leak as well.

I don't know how somebody could put it together like that but they sure did.
No oil seeping at all, luckily. Just a slight misalignment - not enough to prevent assembly of the intake manifold per say, but enough to leave a space to activate the O2 sensor error. It's been a week and I have driven and let it idle for long periods and can confirm that all is in order.

As for your situation with the spring installed incorrectly...yikes, that's pretty insane. I mean if you look at the whole set up, it becomes apparent that the spring is there to push something against another thing perpetually, so it makes no sense to put the spring in the middle of the tube just sitting there freely doing nothing.

So I got my inspection done today and as I was driving home the fuel gauge went kaputt. So now I have to test the lines and start the process of elimination all over again in relation to the fuel sending system.
Mike W.
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Re: SOLVED: 1988 528e Purge Valve Part Number

Post by Mike W. »

matreyia wrote: Jun 13, 2022 5:42 PM What a strange response.

If there is a part that is clearly visibly damaged with cracked or missing or falling off parts..or visibly leaking, you replace that part as per normal protocol.

I have no idea why you got worked up, but ok, see you later. I have no time to spend on people like you. Good lord.
He must have been having a bad day or something, he's been here a while and I don't ever recall him going off like that on someone.
kojo96
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Re: SOLVED: 1988 528e Purge Valve Part Number

Post by kojo96 »

Mike W. wrote: Jun 13, 2022 11:17 PM
matreyia wrote: Jun 13, 2022 5:42 PM What a strange response.

If there is a part that is clearly visibly damaged with cracked or missing or falling off parts..or visibly leaking, you replace that part as per normal protocol.

I have no idea why you got worked up, but ok, see you later. I have no time to spend on people like you. Good lord.
He must have been having a bad day or something, he's been here a while and I don't ever recall him going off like that on someone.
Sorry Mike, but that is more often than not his regular demeanor. With a lame ass excuse at the end of the silly comment in an attempt to excuse himself .
OP, don't even pay any attention to the noise, nobody else does.
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