E60 530i RPM Fluctuation issue

[hammi]

Hello,
Just bought a 530i E60 2005. Car has 178K Kms on it. I'm facing a issue on it while driving. The rpm fluctuates on low speed. I'm posting a video for reference.

[taimurahmed92]

You could be looking at anything from maf sensor to vacuum leaks. Goras use a smoke machine to check for vacuum leaks.

[hammi]

Its something related with the tranny feels like the TC engaging/disengaging.

[hammi]

@Xulfiqar

[hammi]

Got the tranny serviced today. Cleaned the Valve body and replaced filter. Can I use MB 236.14 oil in it? @Xulfiqar

[hammi]

[Xulfiqar]

Did you replace the mechatronic sleeve and also the little bridge seals?

While refurbing the valvebody did you also check those little dampers that are seated in it? They need to be replaced with updated parts.

Firstly make sure your problem is in the engine or transmission, this is a valvetronic engine meaning it idles with no vacuum in the intake manifold and has 100% open throttle almost all the time. The engine crankcase has modulated vacuum from the vacuum pump via the ccv diaphragm setup built into the valve cover, if you have too high vacuum in the crankcase then the valvecover is probably bad and needs to be changed.

Check the engine tune with a scan tool, to see the vanos and valvetronic positions and compare them with good data sets. If they are off then check whats wrong, it maybe a wrongly set timing (check lamp etc) or bad vanos solenoids (common)

If the issue is in the transmission then its the park release solenoid maybe leaky or bad, thats why I asked did you do a proper refurb or a jugaarbaazi refurb.

I wont suggest mercedes atf for it, find zf lifeguard 6 or ford mercon sp fluid.

[hammi]

Seems like the problem is in the transmission. If I put the car in Ds the rpms become stable. I'll share the data with you. I did not do a refurb. Just cleaned the valve body and replaced the trans filter. I have already put merc oil in it. Although haven't started the car yet. According to the mech its the same oil as lifeguard 6. Should I drain it?

[Xulfiqar]

so the video you posted is before you did the repair?

you are claiming you have put new oil in it but didnt start the car yet - while in the video you are driving it. Anyway the rpm fluctuation seems like the torque converter clutch slipping and then the TCU wants to start to reapply and is failing.

Do you have a scan tool that can show you the commanded TCC vs actual TCC slip? This would confirm it.

[hammi]

No the video is of before the repairs were done. The mechanic persisted me to let him try the car on MB oil. The car is doing the same fluctuation with MB oil as well and downshift are not as smooth as before. Anyhow I have moved the car to another workshop he will flush the MB oil and put BMW oil in it. He said the transmission might need calibration or coding altogether. God knows what the actual issue is.
He got the car scanned on some bmw software he said there are no codes from the transmission or the engine. As of now I just want the gear to come back to how it was before the service at least and start from there. Tomorrow he will flush the MB oil and put in BMW oil. I hope it works

[Xulfiqar]

Is your workshop versed in repairing automatic transmissions internally?

And why did you have the valve body cleaned? In the cleaning was the separator plate changed? Were the solenoids demagnetized and flow tested?

Was this transmission not behaving before the job?

[hammi]

No the workshop doesn't know nothing about automatic trans. I just wanted to get trans oil changed. He opened the valve body altogether as he said he had been doing it on previous cars which I doubt. Nothing was changed in the valve body he only cleaned the valve body and assembled everything back.
Before the job the trans had this issue I shared in the video but downshifts were perfect. I dont know why the downshift are laggy its either the wrong oil or he has messed up with the trans.

[hammi]

Now I have moved the car to another workshop he said he will change the oil first and start from there. I asked him if he can repair the valve body he said its a nightmare to repair these trans and they seldom work. I dont know where to start from now. Can you recommend any good workshop in isb/rwp ?

[hammi]

Gear is back to old position. Downshift is smooth but rpm still fluctuates on low rpm.
Sir @Xulfiqar Can you please list down the tests I can do to identify the issue?
Here is the Vanos values on idle. I find them abnormal.

[Xulfiqar]

you need to refurb the transmission, the bushings for the rear stator support which are the feed for I think clutch E which is engaged in 4-5-6 leaks due to wear. This requires replacement of them which is nearly a transmission overhaul job, it may also be a bad or intermittent solenoid failure. (not fully stroking) which is quite common on aging 6spd ZF units.

the vanos seems a bit off, have the timing checked - any shop owning a BMW NG6 timing set can check it for you. (its quite a tedious job just to check though), If you do find it off, then procure brand new bolts for the VANOS to camshaft and follow the torque and the stretch specification.

If you clear the VANOS learned adaptation you will notice that the engine will start running super rough and may even have the half check lamp too.

[hammi]

I think its a three way TC lock up system. The last TC lock is failing I think. I couldn't find the TC lock up command vs slippage stats though. Also its makes a metallic sound when the lock up fails the rpm falls down and feels like car slowed down. I was seeing a valve body rebuild video. In that video he changed all the solenoids and some rubber parts etc will doing that work or will it also need the clutches and torque to be replaced as well?

[Xulfiqar]

Are you relying on a mechanic or are you capable enough to repair an automatic transmission yourself?

[hammi]

I'm relying on a mechanic. I can source parts and tell him how to replace things learning from some tutorial

[hammi]

Replacing solenoids looks like a pretty easy job

[hammi]

Also before I start the gear repair I want to be sure its the gear thats faulty. My second guess is can it be a bad throttle body? A loose throttle plate or bad actuator motor? Or bad IACV?