Surge at 50-60 mph....

[MO525]

I have a surge that occurs when climbing a hill or when the engine is under a load.
Very gentle but noticable.
That is the only time it does it-wife's car, wife's explanation.

I haven't cleaned the throttle body yet and was going to get some Redline Fuel Injector cleaner to start.....not as easy to find locally as I thought.
I heard Advance Auto Parts carried it....not around here. :(

Thanks for your time.

[ryan roopnarine]

might want to compare the symptoms in this bulletin to the symptoms being exhibited, maybe you should test drive it and see what it does first hand

http://plaza.ufl.edu/rroopnar/SI%20%20Pendelum%20Shifting,%20Delayed%20Gear%20En gagement%20or%20Adapter%20Cas.PDF

redline fuel injector cleaner can be obtained at pepboys (for sure) or any autozone that has the redline water wetter as well.

[winfred]

i find a lot of the time full throttle surging is a slow o2 sensor, if yours is original id replace it, at 180k it's past due and should up the mpg a tad, a fuel filter is a good place to start and how old are the plugs i like bosch super F7LDCR or ngk BKR6EK in m50/52/60

[MO525]

i find a lot of the time full throttle surging is a slow o2 sensor, if yours is original id replace it, at 180k it's past due and should up the mpg a tad, a fuel filter is a good place to start and how old are the plugs i like bosch super F7LDCR or ngk BKR6EK in m50/52/60

The O2 sensor is definitely a mystery.
I don't know it's history.
Definitely a "next on my list", though.

I know it's not a transmission issue, though.

[ryan roopnarine]

I know it's not a transmission issue, though.


that's why i suggested that you drive the car yourself and find out exactly what speed it occurs at..at one time, my car surged at about 45 mph when held steady (descending hills) over and over again because of a leaking fuel injector....people here have had the Pendulum transmission issue happen to them in the gm tranny on 525is, scott C took some pictures when he rebuilt his to see the orange gasket that fails when the "pendulum" issue occurs...its important that you find out what its doing first hand.

[MO525]

that's why i suggested that you drive the car yourself and find out exactly what speed it occurs at..at one time, my car surged at about 45 mph when held steady (descending hills) over and over again because of a leaking fuel injector....people here have had the Pendulum transmission issue happen to them in the gm tranny on 525is, scott C took some pictures when he rebuilt his to see the orange gasket that fails when the "pendulum" issue occurs...its important that you find out what its doing first hand.

It's monsoon season here.
I'm hoping tomorrow is a bit drier.
It rains so hard from time to time, you can't hear yourself think inside the car, much less concentrate on hearing/feeling for "problems".
The wife still swears it's only "going up hills, giving it throttle, 45-50 mph".
I'll sure keep you posted.
Thanks for the link...it's still downloading!! Darned Dial-Up. :(

[MO525]

might want to compare the symptoms in this bulletin to the symptoms being exhibited, maybe you should test drive it and see what it does first hand

http://plaza.ufl.edu/rroopnar/SI%20%20Pendelum%20Shifting,%20Delayed%20Gear%20En gagement%20or%20Adapter%20Cas.PDF

redline fuel injector cleaner can be obtained at pepboys (for sure) or any autozone that has the redline water wetter as well.

EXCELLENT link, Ryan.
Thanks so much for taking the time to post that.
I bookmarked it!

I went through the "What to look for's" it appears that the Pendulum shifting issue is not what we're experiencing (THANK goodness).
Why do I think that?
RPM variation during the "surge": Is MINUTE, not the "approx. 500 rpm" the tech. bulletin states.
Cold start-up/shifting: NO problems. No delays and immediate response.
55-65 mph "hunting": NO problems. The car is a DREAM on the highway.

The surge my wife is speaking of does not act like a "shifting in and out" issue, more like a (for a lack of better terms) "VERY slight and smooth miss".

I WILL drive it on Monday and report back.

Thanks for all the input, folks!!!

[Luftpost]

might want to compare the symptoms in this bulletin to the symptoms being exhibited, maybe you should test drive it and see what it does first hand

http://plaza.ufl.edu/rroopnar/SI%20%20Pendelum%20Shifting,%20Delayed%20Gear%20En gagement%20or%20Adapter%20Cas.PDF

redline fuel injector cleaner can be obtained at pepboys (for sure) or any autozone that has the redline water wetter as well.

It seems mine suffers exactly as described in the bulletin. I have both the "pendulum gear hunting" and the tranny leak.

Labor allowance code is 23. Any idea what that means in hours? Hopefully not 23 hrs........ :p

Thanks for the link....sort of.

[ryan roopnarine]

here are some pics from the old board archive (courtesy of scott council) showing what had to be replaced, methinks its basically a transmission rebuild to fix it, as far as labor time is concerned.


http://www.bimmernut.com/wwwboard/e34/messages/32265.html



It seems mine suffers exactly as described in the bulletin. I have both the "pendulum gear hunting" and the tranny leak.

Labor allowance code is 23. Any idea what that means in hours? Hopefully not 23 hrs........ :p

Thanks for the link....sort of.

[MO525]

here are some pics from the old board archive (courtesy of scott council) showing what had to be replaced, methinks its basically a transmission rebuild to fix it, as far as labor time is concerned.


http://www.bimmernut.com/wwwboard/e34/messages/32265.html

Wow, THAT was gut-wrenching.

It appears to me that the gasket curled up/shrank...from some god-awfull amount of heat.....the standard death knell of most automatics.
Whew.
That had BIG dollar signs written all over it.

Thanks for another VERY informative link, Ryan!

[MO525]

I have a surge that occurs when climbing a hill or when the engine is under a load.
Very gentle but noticable.
That is the only time it does it-wife's car, wife's explanation.

I haven't cleaned the throttle body yet and was going to get some Redline Fuel Injector cleaner to start.....not as easy to find locally as I thought.
I heard Advance Auto Parts carried it....not around here. :(

Thanks for your time.

I went for a ride with my wife today.
The "surge" actually occurs at 40-50 mph when under load going uphill.
It's VERY subtle, almost like a subdued miss.
Hard to explain. A miss would be more "Jerky".
This is REAL smooth, in and out, in and out.....with VERY little RPM fluctuation at all.

Any ideas?

I put in some Redline fuel injector cleaner in this tank and will do another bottle-next tankful.

Clogged/half-clogged injector, possibly?

I looked at the O2 sensor, it's SHINY.
Possibly replaced recently?

[sbcncsu]

Wow, THAT was gut-wrenching.

It appears to me that the gasket curled up/shrank...from some god-awfull amount of heat.....the standard death knell of most automatics.
Whew.
That had BIG dollar signs written all over it.

Thanks for another VERY informative link, Ryan!

The worst part was that the rest of the transmission was perfect. The clutches and steel clutch plates were perfect, no wear, no heat discoloration of the steels. If you have the pendulum shift problem, do not foot the bill for a full rebuild, it is unnecessary. BMW sells that kit to fix the problem and the labor will be MUCH less. The gaskets that fail are in the front of the trans and full disassembly is NOT necessary. If I knew then what I know now, I would have just replaced the parts supplied in the kit from BMW. Instead, I employed the help of a close friend and Transmission rebuilder to rebuild the entire thing. Like I said, it was perfect inside....


If your car exhibits pendulum shift or the delayed engagement, the longer you wait, the more wear will occur on the clutches. The blown out gaskets are the cause of the low hydraulic pressure that engages the clutches and causes the slip and the on-off-on-off pendulum shift. The last way to tell if your car has the blown intermediate housing gaskets is a tell-tale leak of ATF from between the two pans, this is the location of the gaskets.

HTH

[MO525]

The worst part was that the rest of the transmission was perfect. The clutches and steel clutch plates were perfect, no wear, no heat discoloration of the steels. If you have the pendulum shift problem, do not foot the bill for a full rebuild, it is unnecessary. BMW sells that kit to fix the problem and the labor will be MUCH less. The gaskets that fail are in the front of the trans and full disassembly is NOT necessary. If I knew then what I know now, I would have just replaced the parts supplied in the kit from BMW. Instead, I employed the help of a close friend and Transmission rebuilder to rebuild the entire thing. Like I said, it was perfect inside....


If your car exhibits pendulum shift or the delayed engagement, the longer you wait, the more wear will occur on the clutches. The blown out gaskets are the cause of the low hydraulic pressure that engages the clutches and causes the slip and the on-off-on-off pendulum shift. The last way to tell if your car has the blown intermediate housing gaskets is a tell-tale leak of ATF from between the two pans, this is the location of the gaskets.

HTH

Thanks for the description!
I hear you though, on the hind sight.
"You live and you learn", right? :)